View
4
Download
0
Category
Preview:
Citation preview
2012 IMC Performing
Commercial Mechanical
Inspections
Based Primarily on the 2012 International
Mechanical Code® (IMC®) and the 2012
International Fuel Gas Code® (IFGC®) as
applicable.
`
Welcome
▪ I am…
▪ You are…
▪ What do you do?
▪ Where are you from?
▪ How familiar are you with the IMC and/or
IFGC?
▪ What do you hope to get out of this seminar?
2012 IMC Performing Commercial Mechanical Inspection 2
Overview
▪ General Mechanical Inspection
▪ Performing Appliance Inspection
▪ Performing Inspections of Fireplaces and
Solid Fuel Appliances
▪ Performing Inspections of Piping Systems
2012 IMC Performing Commercial Mechanical Inspection 3
Overview
▪ Performing Ventilation Inspections
▪ Performing Inspections of Combustion Air
Provisions (Gas) and NonGas
▪ Performing Venting Systems Inspections
▪ Performing Inspections of Exhaust
Systems
2012 IMC Performing Commercial Mechanical Inspection 4
Overview
▪ Performing Inspections of Ducts and
Plenums
▪ Performing Refrigeration Inspections
▪ Performing Inspections of Gas Piping
Installations
2012 IMC Performing Commercial Mechanical Inspection 5
Objectives
▪ Upon completion of this seminar, you will
be better able to:
▪ Define basic terms related to a commercial
mechanical inspection.
▪ Describe the mechanical inspection process
in a step-by-step fashion.
▪ Explain concepts of specific requirements.
▪ Determine if a given commercial occupancy
complies with the 2012 IMC and 2012 IFGC.
Workbook Page 1 2012 IMC Performing Commercial Mechanical Inspection 6
Objectives
▪ Upon completion of this seminar, you will
be better able to:
▪ Locate and apply mechanical code
requirements.
▪ Complete inspection checklists.
▪ Utilize the 2012 IMC and 2012 International
Fuel Gas Code (IFGC) to conduct commercial
building inspections.
Workbook Page 12012 IMC Performing Commercial Mechanical Inspection 7
General Mechanical Inspection
Module 1
2012 IMC Performing Commercial Mechanical Inspection 8
Performing Required General
Inspections
1. Check underground installations.
IMC and IFGC Section 107.2
2. Check rough-in components.
IMC and IFGC Section 107.2
3. Perform the final inspection.
IMC and IFGC Section 107.2
4. Review evaluations and inspection reports.
IMC and IFGC Section 107.2.
Workbook Page 9-102012 IMC Performing Commercial Mechanical Inspection 9
Observing/Verifying Tests IMC and IFGC Section 107.3
1. Check for proper testing apparatus
IMC and IFGC Section 107.3.2
2. Verify and/or observe tests.
IMC and IFGC Section 107.3
3. Retest failures.
IMC and IFGC Section 107.3.3
Workbook Page 11-122012 IMC Performing Commercial Mechanical Inspection 10
Performing Clearance to
Combustibles InspectionsIMC and IFGC Section 308
▪ Two tasks:
1. Inspect clearances
All IMC and IFGC
Section 308
2. Inspect clearance
reduction methods.
IMC and IFGC Table
308.6
2012 IMC Performing Commercial Mechanical Inspection 11Workbook Page 13
How To Measure
▪ IMC Table
308.6/IFGC Table
308.2
Workbook Page 142012 IMC Performing Commercial Mechanical Inspection 12
Task 1: Inspect ClearancesIMC and IFGC Section 308
▪ While performing an inspection you find a
finished wood door that opens to within an inch
of an appliance that requires a minimum
clearance of 12 inches (305 mm). An installer
tries to convince you that a fire hazard is not
present since the door is mechanically closed
automatically.
▪ As a code official, what would you do?
▪ How would you explain your position to the
contractor?
Workbook Page 14 2012 IMC Performing Commercial Mechanical Inspection 13
Task 2: Inspect Clearance
Reduction
1. Check that reduction is allowed.
IMC Section 308.2
2. Check listed appliances and equipment.
3. Check protective assembly construction and
installation.
IMC Section 308.3
4. Check allowable reduction.
Workbook Page 15-16 2012 IMC Performing Commercial Mechanical Inspection 14
Reduced Clearance for 3 ½ -inch
Brick Wall
For SI: 1 inch = 25.4 mm
Workbook Page 15-16 2012 IMC Performing Commercial Mechanical Inspection 15
From IMC
Table 308.6
and IFGC
Table 308.2
Reduced Clearance to Combustibles
Using Protective Assemblies
Workbook Page 15-16 2012 IMC Performing Commercial Mechanical Inspection 16
Performing Protection of
Structure InspectionsIMC and IFGC Section 302
▪ Four tasks:
1. Inspect structural safety.
IMC and IFGC Section 302.1
2. Inspect cutting, notching and boring in wood
framing.
IMC and IFGC Section 302.3
3. Inspect alterations to trusses.
IMC and IFGC Section 302.4
4. Inspect cutting, notching and boring in steel framing.
IMC and IFCGC Section 302.5
Workbook Page 17
2012 IMC Performing Commercial Mechanical Inspection 17
Task 1: Inspect Structural Safety
1. Check for structure weakening.
IMC Section 302.3.2/IFGC Section 302.3.3
2. Check structural condition after structural
alterations.
IMC and IFGC Section 302.1
3. Check protection of penetrations of floor/ceiling
assemblies and fire-resistance-rated
assemblies.
IMC Section and IFGC 302.2
Workbook Page 18 2012 IMC Performing Commercial Mechanical Inspection 18
Task 2: Inspect Cutting, Notching
and Boring in Wood Framing
1. Check joist notching.
IMC Section 302.3.1/IFGC Section 302.3.2
2. Check stud cutting and notching.
IMC Section 302.3.2/IFGC Section 302.3.3
3. Check bored holes.
IMC Section 302.3.3/IFGC Section 302.3.4
4. Check engineered wood products.
IMC Section 302.3.4/IFGC Section 302.3.1
Workbook Page 19-20 2012 IMC Performing Commercial Mechanical Inspection 19
Limitations for Cutting, Notching
and Bored Holes
Workbook Page 19-20 2012 IMC Performing Commercial Mechanical Inspection 20
Bored Hole Limitations
Workbook Page 19-20 2012 IMC Performing Commercial Mechanical Inspection 21
Task 3: Inspect Alterations to
Trusses
1. Check truss condition.
IMC and IFGC Section 302.4
2. Check for alterations that add to loads of
trusses.
IMC and IFGC Section 302.4
Workbook Page 21 2012 IMC Performing Commercial Mechanical Inspection 22
Task 4: Inspect Cutting, Notching
and Boring in Steel Framing
1. Check cutting, notching and boring holes in
structural steel framing.
IMC Section 302.5.1/IFGC Section 302.5
2. Check cutting, notching and boring holes in
cold-formed steel framing.
IMC Section 302.5.2/IFGC Section 302.6
3. Check cutting, notching and boring holes in
nonstructural cold-formed steel wall framing.
IMC Section 302.5.3/IFGC Section 302.7
Workbook Page 222012 IMC Performing Commercial Mechanical Inspection 23
Performing Appliance
Inspections
Module 2
2012 IMC Performing Commercial Mechanical Inspection 24
Performing Appliance Location
InspectionsIMC and IFGC Section 303
▪ Three tasks:
1. Inspect general locations.
IM and IFGC Section 303.1
2. Inspect indoor locations.
IMC and IFGC Section 303.5
3. Inspect outdoor locations.
IMC and IFGC Section 303.6
2012 IMC Performing Commercial Mechanical Inspection 25Workbook Page 25
Task 1: Inspect General
Locations
1. Check for hazardous locations.
IMC and IFGC Section 303.2
2. Check for prohibited locations.
IMC and IFGC Section 303.3
3. Check for protection from damage.
IMC and IFGC Section 303.4
Workbook Page 262012 IMC Performing Commercial Mechanical Inspection 26
Task 2: Inspect Indoor Locations
1. Check room volume.
IMC and IFGC Section 303.5
2. Check fuel-fired furnaces and boilers installed
in closets and alcoves.
IMC Section 303.5
3. Check elevator shafts.
IMC Section 303.8/IFGC Section 301.15
Workbook Page 272012 IMC Performing Commercial Mechanical Inspection 27
Task 3: Inspect Outdoor
Locations
▪ Check for outdoor listings and labels.
▪ Verify that any appliances that are installed
outdoors are listed and labeled for outdoor
installation or are protected as required
IMC and IFGC Section 303.6
Workbook Page 272012 IMC Performing Commercial Mechanical Inspection 28
Public GarageIMC Section 304.6/IFGC Section 304.5
2012 IMC Performing Commercial Mechanical Inspection 29
Public 8 ft. Min. 1 ft. above higher than the tallest vehicle.
Private GarageIMC Section 304.6/IFGC Section 304.5
2012 IMC Performing Commercial Mechanical Inspection 30
Performing Appliance Access
Inspections ▪ Five tasks:
1. Inspect appliances in rooms.
IMC and IFGC Section 306.2
2. Inspect appliances in attics.
IMC and IFGC Section 306.3
3. Inspect appliances under floors.
IMC and IFGC Section 306.4
4. Inspect equipment and appliances on roofs and
elevated structures.
IMC and IFGC Section 306.5
5. Inspect appliances on sloped roofs.
IMC and IFGC Section 306.5.1
Workbook Page 28 2012 IMC Performing Commercial Mechanical Inspection 31
Task 1: Inspect Appliances in
Rooms IMC and IFGC Section 306.2
1. Check for compliance with access
requirements.
IMC and IFGC Sections 306.3 thru 306.4
2. Check central furnaces installed in
compartments or alcoves.
IMC Section 306.1.1
Workbook Page 29 2012 IMC Performing Commercial Mechanical Inspection 32
Task 2: Inspect Appliances in
Attics IMC and IFGC Section 306.3
1. Check for compliance with access
requirements.
IMC and IFGC Section 306.3
2. Check for compliance with electrical
requirements.
IMC Section 306.4.1/IFGC Section 306.3.1
Workbook Page 30 2012 IMC Performing Commercial Mechanical Inspection 33
Attic Location Requirements
Workbook Page 30 2012 IMC Performing Commercial Mechanical Inspection 34
Task 3: Inspect Appliances
Under Floors IMC and IFGC Section 306.4
1. Check for compliance with access
requirements.
IMC and IFGC Section 306.4
2. Check for compliance with electrical
requirements.
IMC and IFGC Section 306.4.1
Workbook Page 312012 IMC Performing Commercial Mechanical Inspection 35
Task 4: Inspect Equipment and Appliances on
Roofs and Elevated Structures
1. Check for permanent approved means of
access.
IMC and IFGC Section 306.5
2. Check for obstacles to access and access
safety.
IMC and IFGC Section 306.5
3. Check permanent ladders.
IMC and IFGC Section 306.5
4. Check catwalks.
IMC and IFGC Section 306.5
Workbook Page 32-33 2012 IMC Performing Commercial Mechanical Inspection 36
Task 5: Inspect Sloped Roofs IMC and IFGC Section 306.5.1
1. Check for level platforms.
2. Check platform dimensions.
3. Check for guards on platform.
Workbook Page 34 2012 IMC Performing Commercial Mechanical Inspection 37
Access Platform On Roof
Workbook Page 342012 IMC Performing Commercial Mechanical Inspection 38
Guards
2012 IMC Performing Commercial Mechanical Inspection 39
Performing Appliance
Installation Inspections
▪ Eight tasks:
1. Examine installation information.
IMC Section 304.1/IFGC Section 305.1
2. Resolve conflicts (if applicable).
IMC Section 304.2/IFGC Section 305.1
3. Inspect installations having ignition sources.
IMC Section 304.3/IFGC Section 305.3
4. Inspect ventilation for hydrogen generating and
refueling operations.
IMC Section 304.5.1 /IFGC Section 703.1
Workbook Page 35 2012 IMC Performing Commercial Mechanical Inspection 40
Performing Appliance
Installation Inspections
▪ Eight tasks (cont.):
5. Inspect garages.
IMC Section 304.6 /IFGC Section 305.4
6. Inspect for boiler and furnace rooms.
IMC Section 304.8 or IFGC Section 305.6.
7. Inspect for Guards
IMC Section 304.11/IFGC Section 306.6
8. Verify clearance from grade.
IMC Section 304.10/IFGC Section 305.7
Workbook Page 352012 IMC Performing Commercial Mechanical Inspection 41
Task 1: Examine Installation
Information
1. Check the manufacturer’s installation
instructions.
IMC Section 304.1/IFGC Section 305.1
2. Check the applicable IMC/IFGC code sections.
IMC Section 304.1/
IFGC Section 305.1
3. Compare the two.
Workbook Page 36 2012 IMC Performing Commercial Mechanical Inspection 42
Task 2: Resolve ConflictsIMC Section 304.2 or IFGC Section 305.1
1. Identify if installation information contains
conflicts.
IMC Section 304.2/IFGC Section 305.1
2. Resolve the conflict.
IMC Section 304.2/IFGC Section 305.1
Workbook Page 372012 IMC Performing Commercial Mechanical Inspection 43
Task 3: Inspect Installations
Having Ignition Sources IMC Section 304.3 or IFGC Section 305.3
1. Check if the ignition source is located in a
hazardous location. .
IMC Section 304.3/IFGC Section 305.3
2. Check the elevation of ignition source.
IMC Section 304.3/IFGC Section 305.3
Workbook Page 38 2012 IMC Performing Commercial Mechanical Inspection 44
Oil-fired Water Heater Installation
in a Hazardous Area
2012 IMC Performing Commercial Mechanical Inspection 45Workbook Page 38
Task 4: Inspect Ventilation for Hydrogen
Generating and Refueling Operations IMC Section 304.5 or IFGC Section 703.1
1. Check for compliance with code requirements.
IMC Section 304.4/IFGC 703.1
2. Check natural ventilation
IMC Section 304.5/IFGC 703.1.1
3. Check mechanical ventilation
IMC Section 304.5.2/IFGC 703.1.2
4. Check specially engineered installations (if
applicable). IMC Section 304.5.3/IFGC 703.1.3
Workbook Page 39-402012 IMC Performing Commercial Mechanical Inspection 46
Task 5: Inspect Garages IMC Section 304.6 or IFGC Section 305.4
1. Check public garages.
IMC Section 304.6/IFGC 305.4
2. Check private garages.
IMC Section 304.7/IFGC 305.5
Workbook Page 412012 IMC Performing Commercial Mechanical Inspection 47
Appliance Installation in a Public
Garage
2012 IMC Performing Commercial Mechanical Inspection 48
1
Workbook Page 41
Task 6: Inspect Boiler and
Furnace Rooms IMC Section 304.8/IFGC Section .305.6
▪ Verify that boiler and furnace rooms are
protected as required by the International
Building Code.
IMC Section 304.8/IFGC Section 305.6
Workbook Page 412012 IMC Performing Commercial Mechanical Inspection 49
Task 7: Inspect for Guards IMC Section 304.11 or IFGC Section 306.6
1. Check that guards are present where
required.
2. Check guard extensions.
3. Check the top of the guard(s).
4. Check guard construction.
2012 IMC Performing Commercial Mechanical Inspection 50Workbook Page 42
Guards
2012 IMC Performing Commercial Mechanical Inspection 51Workbook Page 42
Guards – Plan View
2012 IMC Performing Commercial Mechanical Inspection 52Workbook Page 42
Task 8: Verify Clearance from
Grade IMC Section 304.10 and IFGC Section 305.7
▪ Check for appliance supports
A. Verify that these appliances and equipment are
installed on a level concrete slab or other approved
material extending not less than 3 inches (76 mm)
above adjoining grade.
OR
B. Verify that the appliance or equipment is suspended
at least 6 inches (152 mm) above adjoining grade.
Workbook Page 432012 IMC Performing Commercial Mechanical Inspection 53
Performing Inspections of Fireplaces
and Solid Fuel Appliances
Module 3
2012 IMC Performing Commercial Mechanical Inspection 54
Performing Inspections of Fireplaces and
Solid Fuel-burning Appliances Tasks
▪ Inspect masonry fireplaces.
IMC Section 902.1
▪ Inspect factory-built fireplaces.
IMC Section 903.1 (Section 903.2 NEW)
▪ Inspect fireplace stoves and room heaters, pellet
fuel appliances, and barbecue appliances.
IMC Section 905.1
Workbook Page 452012 IMC Performing Commercial Mechanical Inspection 55
Task 1: Inspect Masonry
Fireplaces IMC Section 902
▪ Check that masonry fireplaces are built
according to the IBC.
▪ Verify that any masonry fireplaces comply with
the masonry construction provisions of the IBC.
IMC Section 902.1
Workbook Page 472012 IMC Performing Commercial Mechanical Inspection 56
Task 2: Inspect Factory Built
Fireplaces IMC Section 903
▪ Check fireplace and chimney installation.
IMC Section 905.2 and IFGC Section 903.1
▪ Check hearth extensions.
IMC Section 903.2
▪ Check appliance installed in fireplaces
(unvented gas log).
IMC Section 903.3 and UL 127
Workbook Page 47-482012 IMC Performing Commercial Mechanical Inspection 57
Typical Factory-build Fireplace
With Hearth
2012 IMC Performing Commercial Mechanical Inspection 58
Workbook Page 47
Task 3: Inspect Fireplace Stoves and Room
Heaters, Pellet Fuel Appliances and Barbecue
appliances IMC Section 906
1. Check installation.
IMC Section 3905/IFGC
Section 602
2. Check for pellet fuel
burning appliances vent
connection. IMC Section
904
3. Check barbecue
appliances for compliance
with IMC Section 906 and
IFGC Section 623.1
2012 IMC Performing Commercial Mechanical Inspection 59Workbook Page 48-49
Performing Inspections of
Piping Systems
Module 4
2012 IMC Performing Commercial Mechanical Inspection 60
Four Parts
▪ Performing inspections of hydronic piping
IMC Chapter 12
▪ Performing inspections of refrigerant piping
IMC Chapter 11
▪ Performing inspections of condensate piping
IMC Section 307/IFGC Section 307
▪ Performing inspections of fuel piping and
storage systems
IMC Chapter 13
Workbook Page 512012 IMC Performing Commercial Mechanical Inspection 61
Performing Inspections of
Hydronic Piping IMC Chapter 12
▪ Three tasks:
▪ Inspect piping materials.
IMC Section 1202
▪ Inspect piping installation.
IMC Section 1204
▪ Inspect transfer fluid.
IMC Section 1207
Workbook Page 512012 IMC Performing Commercial Mechanical Inspection 62
Performing Inspections of
Refrigerant Piping IMC Chapter 11
▪ Three tasks:
1. Inspect piping materials.
IMC Section 1107
2. Inspect joints.
IMC Section 1107.6
3. Inspect stop valves.
IMC Section 1107.8
Workbook Page 572012 IMC Performing Commercial Mechanical Inspection 63
Performing Inspections of
Condensate Piping IMC Section 307/IFGC Section 307
▪ Three tasks:
▪ Inspect fuel-burning appliances.
IMC Section 307.1/IFGC Section 307.2
▪ Inspect drain pipe materials and sizes.
IMC Section 307.2.2 and Table 307.2.2/IFGC Section
307.3
▪ Inspect evaporators and cooling coils.
IMC Section 307.2/IFGC Section 307.1
Workbook Page 612012 IMC Performing Commercial Mechanical Inspection 64
Task 1: Inspect Fuel Burning
Appliance Drain
1. Check collection and discharge.
IMC Section 307.1/IFGC Section 307.2.
2. Check horizontal slope.
IMC Section 307.1/IFGC Section 307.2.
3. Check for corrosion resistance.
IMC Section 307.1/IFGC Section 307.3.
4. Check drain size.
IMC Section 307.2.2 and Table 307.2.2/IFGC
Section 307.3.
Workbook Page 622012 IMC Performing Commercial Mechanical Inspection 65
Task 2: Inspect Drain Pipe
Materials and Sizes
1. Check component materials.
IMC Section 307.2.2/IFGC Section 307.3.
2. Check material selection.
IMC Section 307.2.2/IFGC Section 307.3.
3. Check condensate waste and drain line size.
IMC Section 307.2.2and Table 307.2.2/IFGC
Section .
Workbook Page 632012 IMC Performing Commercial Mechanical Inspection 66
Task 3: Inspect Evaporators and
Cooling Coils
1. Check condensate disposal point.
IMC Section 307.2.1
2. Check auxiliary and secondary drain systems.
IMC Section 307.2.3/IFGC Section 307.5.
3. Check traps.
IMC Section 307.2.4/IFGC Section 307.4.
Workbook Page 642012 IMC Performing Commercial Mechanical Inspection 67
Performing Inspections of Fuel
Piping and Storage Systems IMC Chapter 13
▪ Three tasks:
1. Inspect fuel oil piping.
IMC Table 305.4 and 1302.3.
2. Inspect fuel gas piping (IFGC Chapter 4).
3. Inspect hydrogen piping.
IMC Table 305.4 and IFGC Section 704, 705.
Workbook Page 652012 IMC Performing Commercial Mechanical Inspection 68
Task 1: Inspect Fuel Oil Piping
1. Check for IFC
compliance.
IMC Section 1301.1.
2. Check materials.
IMC Section 1302.
3. Check joints and
connections.
IMC Section 1303.
4. Check fuel oil
system installation.
IMC Section 1305
and 1305.2.1.
5. Check fill piping.
IMC Section 1305.6.
6. Check vent piping.
IMC Section 1305.7 .
Workbook Page 66-682012 IMC Performing Commercial Mechanical Inspection 69
Task 2: Inspect Fuel Gas PipingIFGC Chapter 4
1. Identify piping and components owned by
the gas utility company.
2. Check materials and components.
3. Check installation.
4. Check sizing of gas piping.
5. Check gas flow controls.
6. Check appliance connections.
2012 IMC Performing Commercial Mechanical Inspection 70Workbook Page 69-72
Task 3: Inspect Hydrogen Piping IFGC Section 701
1. Check piping. IFGC Section 704
2. Check use. IFGC Section 704.2
3. Verify tests. IFGC Section 705
4. Check location. IFGC Section 706
5. Check for IFC compliance. IFGC Section 704.3
Workbook Page 73-742012 IMC Performing Commercial Mechanical Inspection 71
Performing Ventilation
Inspections
Module 5
2012 IMC Performing Commercial Mechanical Inspection 72
Four Tasks
1. Inspect exit enclosure ventilation.
IMC Section 601.3 (IMC 401.2 has NEW
content)
2. Inspect openings.
IMC Section 401.4
3. Inspect natural ventilation.
IMC Section 402
4. Inspect mechanical ventilation.
IMC Section 403
Workbook Page 752012 IMC Performing Commercial Mechanical Inspection 73
Task 1: Inspect Exit Enclosure
Ventilation
1. Check intake openings.
IMC Section 401.4
2. Check exhaust openings.
IMC Section 501.3.1.
3. Check opening protection.
IMC Section 401.5.
4. Check contaminant sources.
IMC Section 401.6.
Workbook Page 77-782012 IMC Performing Commercial Mechanical Inspection 74
Air Intake Opening Locations
2012 IMC Performing Commercial Mechanical Inspection 75
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm
Workbook Page 77-78
Task 2: Inspect Openings
1. Check intake openings (IMC Section 401.4 -
Ventilation).
2. Check exhaust openings (IMC Section 501.3.1
- Exhaust).
3. Check opening protection (IMC Table 401.5).
4. Check contaminant sources (IMC Section
401.6).
Workbook Page 79-802012 IMC Performing Commercial Mechanical Inspection 76
Economizer
2012 IMC Performing Commercial Mechanical Inspection 77
Task 3: Inspect Natural
Ventilation
1. Check for natural ventilation openings.
IMC Section 402.1.
2. Check ventilation area required.
IMC Section 402.2.
3. Check adjoining spaces.
IMC Section 402.3.
4. Check openings below grade (if present).
IMC Section 402.4.
Workbook Page 812012 IMC Performing Commercial Mechanical Inspection 78
Task 4: Inspect Mechanical
Ventilation
1. Check the ventilation
means.
IMC Section 403.1.
2. Determine the
ventilation rate.
IMC Table 403.3.
3. Check the ventilation
rate.
IMC Table 403.3.
▪
4. Check the
recirculation of air.
IMC Section 403.2.1.
5. Check transfer air, if
being utilized.
IMC Section 403.2.2.
6. Check common
ventilation systems.
IMC Section 403.2.3
Workbook Page 82-962012 IMC Performing Commercial Mechanical Inspection 79
Table
403.3
Required
Outdoor
Ventilation
Air
2012 IMC Performing Commercial Mechanical Inspection 80
Table 403.3
Required
Outdoor
Ventilation
Air
2012 IMC Performing Commercial Mechanical Inspection 81
Table 403.3
Required
Outdoor
Ventilation
Air
2012 IMC Performing Commercial Mechanical Inspection 82
Example 1: Single-zone
Recirculating System
▪ A 3,000-square-foot dining room is served
by a rooftop air-handling unit by means of
ducted ceiling supply registers and ceiling
return grilles. Determine the system
outdoor air intake flow rate (Vot) for the
dining room.
2012 IMC Performing Commercial Mechanical Inspection 83Workbook Page 87-96
Example 1: Single-zone
Recirculating System
▪ Application
▪ This dining room with a single rooftop unit is
considered to be a single-zone system. In order to
determine the outdoor air intake flow rate (Vot) for a
single-zone system using Equation 4-3, the breathing
zone airflow rate (Vbz) of the occupied space must
first be determined using Equation 4-1. Then, the
zone airflow effectiveness (Ez) must be determined in
accordance with Table 403.3.1.2. Next, the zone
outdoor airflow rate (Voz) must be determined using
Equation 4-2. The outdoor air intake flow rate for a
single-zone system is then simply Vot = Voz, Equation
4-3.2012 IMC Performing Commercial Mechanical Inspection 84
Workbook Page 87-96
Example 1: Single-zone
Recirculating System
▪ Step 1: Determine occupant load (Pz) for
the room for use in Equation 4-1:
Vbz = RpPz + RaAz
▪ From Table 403.3 for dining rooms, the
occupant density of 70 occupants/1,000 ft2 is
used:
▪ 3,000 ft2 × 70
▪ 1,000 ft2 = 210 occupants = Pz
2012 IMC Performing Commercial Mechanical Inspection 85Workbook Page 87-96
Example 1: Single-zone
Recirculating System
▪ Step 2: Determine the breathing zone outdoor airflow
(Vbz) for the room:
▪ First, the outdoor air rates for people (Rp) and area
(Ra) must be obtained for the dining room from Table
403.3:
▪ Rp = 7.5 cfm/person and Ra = 0.18 cfm/ft2
▪ Equation 4-1 can now be solved:
▪ Vbz = RpPz + RaAz
▪ Vbz = (7.5 cfm/person × 210 people) + (0.18 cfm/ft2 ×
3,000 ft2)
▪ Vbz = 2,115 cfm
2012 IMC Performing Commercial Mechanical Inspection 86Workbook Page 87-96
Example 1: Single-zone
Recirculating System
▪ Step 3: Determine the zone outdoor
airflow (Voz):
▪ It is given that the room is served by a rooftop air
handling unit by means of ducted ceiling supply
registers and ceiling return grilles. Thus, the zone
air distribution effectiveness (Ez) can be obtained
from Table 403.3.1.2. In cooling mode, Ez = 1.0,
and in heating mode, Ez = 0.8. The most
restrictive value, Ez = 0.8, must be used (assume
that Note g of Table 403.3.1.2 does not apply).
2012 IMC Performing Commercial Mechanical Inspection 87Workbook Page 87-96
Example 1: Single-zone
Recirculating System
▪ Step 3: Determine the zone outdoor
airflow (Voz):
▪ Equation 4-2 can now be solved for the room:
Voz = Vbz
Ez
Cooling Mode: Voz = 2,115
1.0 = 2,115 cfm
Heating Mode: Voz = 2,115
0.8 = 2,644 cfm2012 IMC Performing Commercial Mechanical Inspection 88
Workbook Page 87-96
Example 1: Single-zone
Recirculating System
▪ Step 3: Determine the zone outdoor airflow (Voz):
▪ As a result, the greater system demand for the dining room
requires 2,644 cfm of outdoor air in heating mode. This
value of Voz should be used to determine the maximum
system requirement for outdoor air intake flow rate (Vot),
Equation 4-3:
Vot = Voz = 2,644 cfm
▪ In comparison, the amount of outdoor air required using
the 2006 code would be based on the same occupant
load. However, the outdoor air ratio is 20 cfm per person.
Therefore, the amount of outdoor air is 210 occupants ×
20 cfm/occupant = 4,200 cfm of outdoor air required.
2012 IMC Performing Commercial Mechanical Inspection 89Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ A single-story 8,000-square-foot office building
consists of 7,250 square feet of general office
space and a 500-square-foot conference room.
▪ The building is served by a rooftop unit by means
of ducted ceiling supply registers and ceiling return
grilles. The primary airflow provided by the rooftop
unit is 8,100 cfm for the office space and 780 cfm
for the conference room. Determine the outdoor
air intake flow rate for the system serving the
office area and conference room.
2012 IMC Performing Commercial Mechanical Inspection 90Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ Application
▪ This office area and conference room constitutes two
separate zones that are served by a single rooftop
unit. In order to determine the outdoor air intake flow
rate (Vot) for a multiple-zone system using Equation 4-
8, the breathing zone airflow rate (Vbz) of the occupied
space must first be determined using Equation 4-1.
Then, the zone airflow effectiveness (Ez) must be
determined in accordance with Table 403.3.1.2. Next,
the zone outdoor airflow rate (Voz) must be
determined using Equation 4-2.
2012 IMC Performing Commercial Mechanical Inspection 91Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ Application
▪ After determining the previously listed variables, the
outdoor air intake flow rate for amultiple-zone
recirculating system must be determined using
Sections 403.3.2.3.1 through 403.3.2.3.4. The primary
outdoor air fraction (Zp) must be determined using
Equation 4-5. Then the system ventilation efficiency
(Ev) is determined in accordance with Table
403.3.2.3.2 and the uncorrected outdoor air intake
flow rate (Vou) is determined using Equations 4-6 and
4-7.
2012 IMC Performing Commercial Mechanical Inspection 92Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ Step 1: Determine occupant loads (Pz) for each
zone:
▪ For the general office space (Zone 1), the
occupant density of 5 occupants/1,000 ft2 is used
(from Table 403.3 for office spaces).
▪ Pz (Zone 1) = 7,250 ft2 × 5 occupants/1,000 ft2 =
37
▪ For the conference room (Zone 2), the occupant
density of 50 occupants/1,000 ft2 is used.
▪ Pz (Zone 2) = 500 ft2 × 50 occupants/1000 ft2 =
252012 IMC Performing Commercial Mechanical Inspection 93
Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ Step 2: Determine the breathing zone outdoor
airflow (Vbz) for each zone:
▪ First, the outdoor air rates for people (Rp) and area
(Ra) must be obtained for each zone from Table
403.3:
▪ Zone 1 values: Rp (Zone 1) = 5 cfm/person and Ra
▪ (Zone 1) = 0.06 cfm/ ft2
▪ Zone 2 values: Rp (Zone 2) = 5 cfm/person and Ra
▪ (Zone 2) = 0.06 cfm/ ft2
2012 IMC Performing Commercial Mechanical Inspection 94Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ Step 2: Determine the breathing zone outdoor
airflow (Vbz) for each zone:
▪ Equation 4-1 can now be solved for each zone:
▪ Vbz = RpPz + RaAz
▪ Zone 1: Vbz = (5 cfm/person × 37 people) + (0.06
cfm/ft2 × 7,250 ft2)
▪ Vbz = 620 cfm
▪ Zone 2: Vbz = (5 cfm/person x 25 people) + (0.06
cfm/ft2 × 500 ft2)
▪ Vbz = 155 cfm
2012 IMC Performing Commercial Mechanical Inspection 95Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ Step 3: Determine the zone outdoor
airflow (Voz) for each zone:
▪ It is given that the room is served by a rooftop
air-handling unit by means of ducted ceiling
supply registers and ceiling return grilles.
Thus, the zone air distribution effectiveness
(Ez) can be obtained from Table 403.3.1.2. In
cooling mode, Ez = 1.0, and in heating mode,
Ez = 0.8 (assume that Note g of Table
403.3.1.2 does not apply).
2012 IMC Performing Commercial Mechanical Inspection 96Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ Equation 4-2 can now be solved for each zone:
▪ Voz = Vbz/Ez
▪ Ez
▪ Zone 1: Cooling Mode: Voz = 620 cfm
▪ 1.0 = 620 cfm
▪ Heating Mode: Voz = 620 cfm
▪ 0.8 = 775 cfm
▪ Zone 2: Cooling Mode: Voz = 155 cfm
▪ 1.0 = 155 cfm
▪ Heating Mode: Voz = 155 cfm
▪ 0.8 = 194 cfm2012 IMC Performing Commercial Mechanical Inspection 97
Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ Step 4: Determine the primary outdoor air
fraction (Zp) for each zone:
▪ The primary airflow (Vpz) is given:
▪ Vpz (Zone 1) = 8,100 cfm and Vpz (Zone 2) = 780 cfm.
▪ Equation 4-5 can now be solved for each zone:
▪ Zp =Voz
▪ Vpz
▪ Zone 1: Zp = 775 cfm/8,100 cfm = 0.096
▪ Zone 2: Zp = 194 cfm/780 cfm = 0.25
2012 IMC Performing Commercial Mechanical Inspection 98Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ Step 5: Determine the system ventilation
efficiency (Ev):
▪ The largest value of Zp among all zones
served by the system must be used.
▪ Therefore, for Zp = 0.25, Table 403.3.2.3.2
yields Ev = 0.9.
2012 IMC Performing Commercial Mechanical Inspection 99Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ Step 6: Determine the uncorrected outdoor air intake
flow rate (Vou):
▪ Note that the occupant diversity (D) calculation is optional,
meaning that if no diversity is desired to be applied or if there is
insufficient information for applying Equation 4-7, the designer
can simply set D equal to 1 in Equation 4-6. The occupant
diversity is used to account for occupants who will be either in
one zone or the other at any given time. For this example, it is
assumed that D is equal to 1 so as to make the results of Section
403.3.2.3 more obvious, thereby making the example more
meaningful. If, however, an occupant diversity (D) was applied in
this example it would be calculated as follows:
2012 IMC Performing Commercial Mechanical Inspection 100Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ The design assumption is that the conference
room (Zone 2) may at times be occupied by
outside visitors to conduct a presentation or
meet with the staff with the balance of the
conference room occupancy consisting of
staff. An assumption is made that, on
average, 80 percent of the conference room
zone occupancy will be comprised of staff that
normally occupies the Zone 1 office area.
2012 IMC Performing Commercial Mechanical Inspection 101Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems▪ This results in a system population (Ps) as follows:
▪ Ps = system population = Zone 1 population + Zone 2 visitors
▪ Ps = 37 people + (25 people × 0.2 visitor rate) = 42 occupants
which are expected to be concurrently in all zones served by the
system. The denominator of Equation 4-7 is simply the sum of
the occupant loads of all zones, that being the sum of Zone 1, 37
occupants and Zone 2, 25 occupants.
▪ Equation 4-7 can now be solved for D, occupant diversity:
▪ D =
▪ D = 42 occupants/(37 occupants + 25 occupants) = 42/62 = 0.68
2012 IMC Performing Commercial Mechanical Inspection 102Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ As stated earlier, D = 1 will be used in the remainder
of this example.
▪ Equation 4-6 is solved as follows:
▪ Vou = D × Σall zones RpPz + Σall zones RaAz
▪ Vou = D {[Rp (Zone 1) x Pz (Zone 1)] + [Rp (Zone 2) x
Pz (Zone 2)]} + {[(Ra (Zone 1) × Az (Zone 1)] + [Ra
(Zone 2) × Az (Zone 2)]}
▪ Vou = 1[(5 cfm/person × 37 people) + (5 cfm/ person ×
25 people)] + [(0.06 cfm/ft2 × 7,250 ft2) + (0.06 cfm/ft2
× 500 ft2)]
▪ Vou = 185 + 125 + 435 + 30 = 775 cfm
2012 IMC Performing Commercial Mechanical Inspection 103Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ Step 7: Determine the outdoor air intake flow
rate (Vot):
▪ Equation 4-8 gives the adjusted overall outdoor air
flow rate required for the system, using the most
restrictive value for system ventilation efficiency (Step
5),
▪ Ev:
▪ Vot = Vou
▪ Ev
▪ Vot = 775 cfm/0.9 = 861 cfm
2012 IMC Performing Commercial Mechanical Inspection 104Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ This is the overall amount of outdoor air supplied by
the rooftop unit to both zones.
▪ Now consider what the overall amount of outdoor air
would have been if the Maximum Zp of 0.25 had been
applied to both Zones 1 and 2 instead of working
through the process of calculating the “corrected”
outdoor air intake flow rate as performed in this
example.
▪ For Zone 1, the outdoor/primary air fraction (Zp) of
0.25 would require that 2,025 cfm be supplied to Zone
1 (2,025/8,100 = 0.25).
2012 IMC Performing Commercial Mechanical Inspection 105Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ For Zone 2, the outdoor/primary air fraction (Zp) of
0.25 would require the same as before, 194 cfm.
(194/780 = 0.25).
▪ Adding both zones: 2,025 + 194 = 2,219 cfm. As can
be seen, the process of Section 403.3.2.3 has
reduced (corrected) the outdoor rate by 1,358 cfm. If
the occupant diversity factor (D) had been applied in
this example, the true nature of the “correction” from
Equation 4-8 would have been obscured. In
comparison, the amount of outdoor air required using
the 2006 code would be the following:
2012 IMC Performing Commercial Mechanical Inspection 106Workbook Page 87-96
Example 2: Multiple-zone
Recirculating Systems
▪ Zone 1:
▪ 7,250 ft2 × 7 occupants
▪ 1,000 ft2 = 51 occupants × 20 cfm/occupant = 1,020
cfm OA
▪ Zone 2:
▪ 500 ft2 × 50 occupants
▪ 1,000 ft2 = 25 occupants × 20 cfm/occupant = 500 cfm
OA
▪ Total amount of outdoor air supplied by the rooftop
unit is 1,520 cfm under the 2006 code.
2012 IMC Performing Commercial Mechanical Inspection 107Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems
▪ A wing of a new high school consists of a
2,200-square-foot art classroom, a 1,400-
square-foot science lab, a 1,200-square-
foot computer lab and a 750-square-foot
corridor. The entire wing is to be served by
a single central air-handling unit in an
adjoining mechanical room, via ceiling
supply and ceiling return grilles and
registers.
2012 IMC Performing Commercial Mechanical Inspection 108Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems
▪ The primary airflow provided for the
building consists of 2,800 cfm for the art
classroom, 2,400 cfm for the science lab,
1,800 cfm for the computer lab and 500
cfm for the corridor. Determine the outdoor
air intake flow rate for the building area.
2012 IMC Performing Commercial Mechanical Inspection 109Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems
▪ Step 1: Determine occupant loads (Pz) for each
zone:
▪ For the art classroom (Zone 1), Table 403.3 under the
Education occupancy, the occupant density is:
▪ Pz (Zone 1) = (2,200 ft2/1,000 ft2) × 20 occupants
▪ Pz (Zone 1) = 44 occupants
▪ For the science lab (Zone 2), the maximum
occupancy is given as:
▪ Pz (Zone 2) = (1,400 ft2/1,000 ft2) × 25 = 35
occupants)
2012 IMC Performing Commercial Mechanical Inspection 110Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems▪ For the computer lab (Zone 3), the maximum occupancy
is:
▪ Pz (Zone 3) = (1,200 ft2/1,000 ft2) × 25 occupants
▪ Pz (Zone 3) = 30 occupants
▪ For the corridor (Zone 4), no specific occupancy criterion is
given; therefore, from Table 403.3 under the Education
occupancy, the table says to go to Public Spaces for
corridor requirements. The table entry for corridors does
not have a value listed in the Occupant Density or People
outdoor air rate columns; therefore, Pz (Zone 4) = 0, and
only requires the Area Outdoor Airflow Rate in Breathing
Zone component to be considered, which will occur later in
the example.
2012 IMC Performing Commercial Mechanical Inspection 111Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems
▪ Step 2: Determine the breathing zone outdoor
airflow (Vbz) for each zone:
▪ First, the outdoor air rates for people (Rp) and area (Ra)
must be obtained for each zone from Table 403.3:
▪ Zone 1 values Rp (Zone 1) = 10 cfm/person; Ra (Zone 1) =
0.18 cfm/ft2
▪ Zone 2 values: Rp (Zone 2) = 10 cfm/person; Ra (Zone 2) =
0.18 cfm/ft2
▪ Zone 3 values: Rp (Zone 3) = 10 cfm/person; Ra (Zone 3) =
0.12 cfm/ft2
▪ Zone 4 values: Rp (Zone 4) = 0 cfm/person; Ra (Zone 4) =
0.06 cfm/ft2
2012 IMC Performing Commercial Mechanical Inspection 112Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems▪ Equation 4-1 can now be solved for each zone:
▪ Vbz = Rp(Pz) + Ra(Az)
▪ Zone 1: Vbz (Zone 1) = 10 cfm/person (44 people) + 0.18 cfm/ft2
(2,200 ft2)
▪ Vbz (Zone 1) = 836 cfm
▪ Zone 2: Vbz (Zone 2) = 10 cfm/person (35 people) + 0.18 cfm/ft2
(1,400 ft2)
▪ Vbz (Zone 2) = 602 cfm
▪ Zone 3: Vbz (Zone 3) = 10 cfm/person (30 people) + 0.12 cfm/sq ft
(1,200 ft2)
▪ Vbz (Zone 3) = 444 cfm
▪ Zone 4: Vbz (Zone 4) = 0 cfm/person (0 people) + 0.06 cfm/sq ft
(750 ft2)
▪ Vbz (Zone 4) = 45 cfm
2012 IMC Performing Commercial Mechanical Inspection 113Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems
▪ Step 3: Determine the zone outdoor
airflow (Voz) for each zone:
▪ It is given that the building is served by a
rooftop air- handling unit via ceiling supply
and ceiling return. Thus, the zone air
distribution effectiveness (Ez) can be obtained
from Table 403.3.1.2; in cooling mode, Ez =
1.0, and in heating mode, Ez = 0.8 (assume
that Note g to the Table is not applicable in
this example).
2012 IMC Performing Commercial Mechanical Inspection 114Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems
▪ Equation 4-2 can now be solved for each zone:
▪ Voz = Vbz /Ez
▪ Zone 1: Cooling Mode Voz (Zone 1) = 836 cfm/1.0 = 836 cfm
▪ Heating Mode: Voz (Zone 1) = 836 cfm/0.8 = 1,045 cfm
▪ Zone 2: Cooling Mode: Voz (Zone 2) = 602 cfm/1.0 = 602 cfm
▪ Heating Mode: Voz (Zone 2) = 602 cfm/0.8 = 753 cfm
▪ Zone 3: Cooling Mode: Voz (Zone 3) = 444 cfm/1.0 = 444 cfm
▪ Heating Mode: Voz (Zone 3) = 444 cfm/0.8 = 555 cfm
▪ Zone 4: Cooling Mode: Voz (Zone 4) = 45 cfm/1.0 = 45 cfm
▪ Heating Mode: Voz (Zone 4) = 45 cfm/0.8 = 57 cfm
2012 IMC Performing Commercial Mechanical Inspection 115Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems
▪ Step 4: Determine the primary outdoor air
fraction (Zp) for each zone:
▪ The primary airflow (Vpz) is given for each Zone: Vpz
(Zone 1) = 2,800 cfm; Vpz
▪ (Zone 2) = 2,400 cfm; Vpz (Zone 3) = 1,800 cfm; and
Vpz (Zone 4) = 500 cfm.
▪ The primary airflow (Vpz) is given for each Zone: Vpz
(Zone 1) = 2,800 cfm; Vpz
▪ (Zone 2) = 2,400 cfm; Vpz (Zone 3) = 1,800 cfm; and
Vpz (Zone 4) = 500 cfm.
▪ Zp = Voz/Vpz
2012 IMC Performing Commercial Mechanical Inspection 116Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems
▪ Step 4: Determine the primary outdoor air
fraction (Zp) for each zone:
▪ Zone 1: Zp (Zone 1) = 1,045 cfm/2,800 cfm = 0.37
▪ Zone 2: Zp (Zone 2) = 753 cfm/2,400 cfm = 0.31
▪ Zone 3: Zp (Zone 3) = 555 cfm/1,800 cfm = 0.31
▪ Zone 4: Zp (Zone 4) = 57 cfm/500 cfm = 0.12
2012 IMC Performing Commercial Mechanical Inspection 117Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems
▪ Step 5: Determine the system ventilation
efficiency (Ev):
▪ The largest value of Zp among all zones
served by the system must be used; thus, for
Zp = 0.37 (largest value among all zones),
Table 403.3.2.3.2 yields a value of 0.7 for Ev.
2012 IMC Performing Commercial Mechanical Inspection 118Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems
▪ Step 6: Determine the uncorrected
outdoor air intake (Vou):
▪ For occupant diversity (D), Equation 4-7 is
used to account for occupants who will either
be in one zone or the other at any given time.
2012 IMC Performing Commercial Mechanical Inspection 119Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems
▪ For this example, the school district has noted that
the art classroom and computer lab will be normally
occupied throughout the school day; however, the
school district estimates that the science lab will be
used only for two or three periods a day for
combined classes and special events; thus, it is only
occupied roughly 50 percent of the school day.
However, since the science lab will draw its
population from other areas of the campus, there is
no assumed occupant diversity between the
classrooms and labs within our analysis.
2012 IMC Performing Commercial Mechanical Inspection 120Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems
▪ Additionally, the corridor will be normally
unoccupied, and will only have occupants
between classes; as such, the corridor does not
factor into the occupancy diversity calculation,
but is considered only for area outdoor air rate.
▪ Since no one zone will draw occupants away
from another zone, the occupant diversity value
for our example is D = 1.0.
2012 IMC Performing Commercial Mechanical Inspection 121Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems
▪ Equation 4-6 can now be solved:
▪ Vou = D [Σall zones (RpPz)] + [Σall zones (RaAz)]
▪ Vou = D {[Rp (Zone 1) × Pz (Zone 1)] + [Rp (Zone 2) × Pz (Zone 2)]
+ [Rp (Zone 3) × Pz (Zone 3)] + [Rp (Zone 4) × Pz (Zone 4)]} +
{[Ra (Zone 1) × Az (Zone 1)] + [Ra(Zone 2) × Az (Zone 2)] + [Ra
(Zone 3) × Az (Zone 3)] + [Ra (Zone 4) × Az (Zone 4)]}
▪ Vou = 1.0 [(10 cfm/person × 44 people) + (10 cfm/person × 35
people) + (10 cfm/person × 30 people) + (0 cfm/person × 0
people)] + [(0.18 cfm/ft2 × 2,200 ft2) + (0.18 cfm/ft2 × 1,400 ft2) +
(0.12 cfm/ft2 × 1,200 ft2) + (0.06 cfm/ft2 × 750 ft2)]
▪ Vou = [1,090] + [837]
▪ Vou = 1,927 cfm
2012 IMC Performing Commercial Mechanical Inspection 122Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems
▪ Step 7: Determine the outdoor air intake flow rate (Vot):
▪ Equation 4-8 gives the adjusted overall outdoor air flow rate
required for the system, using the most restrictive value for
system ventilation efficiency, Ev:
▪ Vot = Vou/Ev
▪ Vot = 1,927 cfm/0.7 = 2,753 cfm
▪ Compare with the 2006 code Table 403.3 method:
▪ Art Classroom = (2,200 ft2/1,000 ft2) × 50 occupants = 110
occupants (110 × 15 cfm/occupant = 1,650 cfm)
▪ Science Lab = (1,400 ft2/1,000 ft2) × 30 occupants = 42
occupants (42 × 20 cfm/occupant = 840 cfm)
▪ Computer Lab = (1,200 ft2/1,000 ft2) × 50 occupants = 60
occupants (60 × 15 cfm/occupant = 900 cfm)
2012 IMC Performing Commercial Mechanical Inspection 123Workbook Page 87-96
Example 3: Multiple-zone
Recirculating Systems
▪ Step 7: Determine the outdoor air intake flow rate (Vot):
▪ Equation 4-8 gives the adjusted overall outdoor air flow rate
required for the system, using the most restrictive value for
system ventilation efficiency, Ev:
▪ Corridor = (750 ft2 × 0.05 cfm/ft2 = 38 cfm)
▪ In the 2006 edition of the code, (1,650 + 840 + 900 + 38) = 3,428
cfm would have been required.
▪ Note that the science lab and computer lab both require an
exhaust system in accordance with Table 403.3, and such
system is in addition to the ventilation calculated in this example
(see Section 403.4).
2012 IMC Performing Commercial Mechanical Inspection 124Workbook Page 87-96
Energy Recovery Ventilation
Systems Section 514
▪ 514.1 General.
▪ Ducted heat recovery ventilators shall be listed and
labeled in accordance with UL 1812. Nonducted heat
recovery ventilators shall be listed and labeled in
accordance with UL 1815.
▪ 514.4 Recirculated air.
▪ Air conveyed within energy recovery systems shall
not be considered as recirculated air where the
energy recovery ventilation system is constructed to
limit cross-leakage between air streams to less than
10 percent of the total airflow design capacity.
2012 IMC Performing Commercial Mechanical Inspection 125Workbook Page 87-96
An Energy-conserving
Alternative to Natural Ventilation
2012 IMC Performing Commercial Mechanical Inspection 126Workbook Page 84-89
Performing Inspections of
Combustion Air provisions (Gas)
and NonGas Fuel Installation
Module 6
2012 IMC Performing Commercial Mechanical Inspection 127
Five Parts
▪ Performing inspections of indoor air (gas).
IFGC Section 304.5.
▪ Performing inspections of outdoor air provisions.
IFGC Section 304.6.
▪ Performing inspection of combination
indoor/outdoor air.
IFGC Section 304.7.
▪ Performing inspections of engineered systems
and combustion air supply.
IFGC Section 304.8.
Workbook Page 972012 IMC Performing Commercial Mechanical Inspection 128
Five Parts (cont.)
▪ Performing inspection of mechanical combustion
air supply.
Mechanical Combustion Air Supply.
IFGC Section 304.9
Workbook Page 972012 IMC Performing Commercial Mechanical Inspection 129
Task 1: Inspect Indoor Air
1. Determine the required indoor volume.
IFGC Section 304.5.1 and 304.5.2
2. Check indoor opening size and location.
IFGC Section 304.5.3.
Workbook Page 99-
100
2012 IMC Performing Commercial Mechanical Inspection 130
All Air from Inside the Building
2012 IMC Performing Commercial Mechanical Inspection 131Workbook Page 99-100
Performing Inspections for
Outdoor Air (Gas) Provisions
▪ Three tasks:
1. Inspect air opening dimensions.
IFGC Section 304.6.
2. Inspect two-permanent-opening method.
IFGC Section 304.6.1.
3. Inspect one-permanent-opening method.
IFGC Section 304.6.2.
Workbook Page 1012012 IMC Performing Commercial Mechanical Inspection 132
Task 1: Inspect Air Opening
Dimensions
▪ Check minimum dimension of any air opening.
IFGC Section 304.5.3, 304.5.3.1 and 304.5.3.2.
Workbook Page 1022012 IMC Performing Commercial Mechanical Inspection 133
Task 2: Inspect Two-Permanent-
Opening Method
▪ Check opening location.
IFGC Section304.5.3.
▪ Check communication to the outdoors.
IFGC Section 304.6
Workbook Page 1022012 IMC Performing Commercial Mechanical Inspection 134
Inlet Air from Ventilated Crawl Space
and Outlet Air to Ventilated Attic
2012 IMC Performing Commercial Mechanical Inspection 135Workbook Page 102
Inlet Air from Inlet Duct and
Outlet Air to Ventilated Attic
2012 IMC Performing Commercial Mechanical Inspection 136
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm
Workbook Page 102
All Air from Outdoors
2012 IMC Performing Commercial Mechanical Inspection 137Workbook Page 102
Task 3: Inspect One-Permanent-
Opening Method
1. Check opening location.
IFGC Section 304.6.2.
2. Combination Indoor and Outdoor Combustion
air. IFGC 304.7
3. Check communication to the outdoors.
IFGC Section 304.7.1.
4. Check clearances.
IFGC Section 304.7.1.
Workbook Page 1032012 IMC Performing Commercial Mechanical Inspection 138
One-Permanent-Opening Method, All
Air from the Outdoors
2012 IMC Performing Commercial Mechanical Inspection 139Workbook Page 103
Performing Inspections of
Combination Indoor/Outdoor Air
▪ Three tasks:
1. Inspect indoor openings.
IFGC Section 304.7.1.
2. Inspect outdoor opening location.
IFGC Section 304.7.2.
3. Inspect outdoor opening(s) size.
IFGC Section 304.7.3.
Workbook Page 1042012 IMC Performing Commercial Mechanical Inspection 140
Task 1: Inspect Indoor Openings
1. Check for the minimum free area.
IFGC Section 304.7.3.
2. Check opening locations.
IFGC Section 304.7.3.
Workbook Page 1042012 IMC Performing Commercial Mechanical Inspection 141
Task 2: Inspect Outdoor Opening
Location
▪ Check opening locations.
IFGC Section 304.7.3 and 304.10
Workbook Page 1052012 IMC Performing Commercial Mechanical Inspection 142
Task 3: Inspect Outdoor
Opening(s) Size
▪ Check outdoor opening sizes.
IFGC Section 304.6, 304.6.1 and 304.6.2.
Workbook Page 1052012 IMC Performing Commercial Mechanical Inspection 143
Performing Inspections of Engineered
Systems and Mechanical Combustion Air
Supply
▪ Two tasks:
1. Inspect engineered systems.
IFGC Section 304.8.
2. Inspect mechanical combustion air supply.
IFGC Section 304.9.
Workbook Page 1062012 IMC Performing Commercial Mechanical Inspection 144
Task 1: Inspect Engineered
Systems
▪ Verify that engineered systems meet the intent
of the code.
IFGC Section 304.8.
Workbook Page 1062012 IMC Performing Commercial Mechanical Inspection 145
Task 2: Inspect Mechanical
Combustion Air Supply
1. Check outdoor air supply rate.
IFGC section 304.9
2. Check makeup air.
IFGVC Section 304.9.1.
3. Check appliance interlock.
IFGC Section 304.9.2.
4. Check combined combustion air and ventilation
air system. IFGC Section 304.9.3.
Workbook Page 1072012 IMC Performing Commercial Mechanical Inspection 146
Mechanical Combustion Air
Supply System IFGC 304.9
2012 IMC Performing Commercial Mechanical Inspection 147Workbook Page 107
Mechanical Combustion Makeup
Air Supply System IFGC 304.9
2012 IMC Performing Commercial Mechanical Inspection 148Workbook Page 107
Mechanical Combustion Makeup
Air Supply System IFGC 304.9
2012 IMC Performing Commercial Mechanical Inspection 149Workbook Page 107
Performing Venting
Systems Inspections
Module 7
2012 IMC Performing Commercial Mechanical Inspection 150
Venting Systems Inspection
Tasks
▪ Inspect for general compliance.
IFGC Section 501.1 and 501.2.
▪ Inspect vents.
IFGC Section 502 and 503.1.
▪ Inspect chimneys.
IFGC Section 501.3., 501.15-501.15.2, 501.15.3
▪ Inspect connectors.
IFGC Section 503.10 and 504.3.2.
▪ Inspect appliance venting.
IFGC Section 503.
Workbook Page 1092012 IMC Performing Commercial Mechanical Inspection 151
Task 1: Inspect for General
Requirements Compliance
▪ Only 1 step
IFGC Section 501.2 and 503.
▪ The critical operating characteristics are as
follows:
▪ Positive or nonpositive (negative or neutral) pressure
within the venting system.
▪ Whether the flue gas generated has a temperature
that approaches the dew point making excessive
condensation likely.
Workbook Page 1112012 IMC Performing Commercial Mechanical Inspection 152
Appliance Categories
2012 IMC Performing Commercial Mechanical Inspection 153
Pressure Excessive Condensation
Positive Non-Positive Avoids Creates
Category I X X
Category
II
X X
Category
III
X X
Category
IV
X vented X
Workbook Page 111
Task 2: Inspect Vents▪ Only one step
IFGC Section 502.1, 503 and 504.
▪ There are six types of venting systems that must
be inspected:
1. Type B gas vent.
2. Type BW gas vent.
3. Type L vent.
4. Chimney.
5. Single-wall metal pipe.
6. Plastic pipe and stainless steel special venting
systems.
Workbook Page 1122012 IMC Performing Commercial Mechanical Inspection 154
Task 3: Inspect Chimneys
1. Check masonry
chimneys.
IFGC Section 501.3
2. Check for common
chimneys or flue-ways.
IFGC Section 501.9.
3. Check gas-fired
appliances.
IFGC Section 503.5.6. 1
4. Check for decorative
shrouds.
IFGC Section 503.6.4.1.
5. Check existing chimneys
and vents.
IFGC Section 501.15.
6. Check sizing of venting
systems.
IFGC Section 501.15.1
2012 IMC Performing Commercial Mechanical Inspection 155Workbook Page 113-118
Decorative ShroudsGas Vents IFGC 503.6.4.1, Chimney IFGC 503.5.4
2012 IMC Performing Commercial Mechanical Inspection 156Workbook Page 113-118
Existing Chimneys and VentsIFGC 501.15
OUTSIDE WALL
REPLACEMENT BOILER-CATEGORY III VENTEDTHROUGH WALL
REMOVED APPLIANCE,PREVIOUS CHIMNEY-CONNECTED BOILER
EXISTING MASONRY CHIMNEY
EXISTING WATER HEATER
CLEAN-OUT
2012 IMC Performing Commercial Mechanical Inspection 157Workbook Page 107-112
Vent System Performance
Factors
2012 IMC Performing Commercial Mechanical Inspection 158Workbook Page 107-112
Task 4: Inspect Connectors
1. Check for potential condensate production.
IFGC Section 503.1 and 503.9.
2. Check connector location.
IFGC Section 503.10 through 503.15.
3. Check combined connectors.
IFGC Section 503.10.3.3.
4. Check offsets.
IFGC Section 503.10.8, 504.2.3 and 504.3.2.
5. Check connector length limit.
IFGC Section 504.3.2 and 503.10.8.
Workbook Page 119-1212012 IMC Performing Commercial Mechanical Inspection 159
Connectors
2012 IMC Performing Commercial Mechanical Inspection 160Workbook Page 119-121
Walking though the Steps:
Connector Length LimitA 3" diameter
B 4" diameter
C 6" diameter
2.5'
4.5'
2'
1'
9.5'
FANOR
DRAFTHOOD
APPLIANCEDRAFTHOODDRAFTHOOD
DRAFTHOOD
2012 IMC Performing Commercial Mechanical Inspection 161
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm
Workbook Page 122
Connector Length Limit -
Answer
A: Actual connector length = 2.5Max. allowed = 4.5
B: Actual connector length = 4.5Max. allowed = 6.0
C: Actual connector length = 9.5Max. allowed = 9.0
2012 IMC Performing Commercial Mechanical Inspection 162Workbook Page 123
Task 4: Inspect Connectors
6. Check for length alternative.
IFGC Section 503.10.8 or 504.3.2.
7. Check for common vent offsets.
IFGC Section 503.6.9.2 or 504.3.5.
8. Check for vent capacity reduction (elbows).
IFGC Section 504.3.6.
9. Check for connector capacity reduction.
IFGC Section 504.3.3.
10.Check seven times rule.
IFGC Section 504.2.8.
Workbook Page 123-1292012 IMC Performing Commercial Mechanical Inspection 163
Step 6 Check for length
altenative
▪ If a furnace is served by a 5-inch (127
mm) vent connector that is 12 feet (3658
mm) in length, the 11/2 feet (457 mm) for
every inch of connector diameter is
exceeded by 41/2 feet (1402 mm).
Therefore, the maximum capacity of the
connector would be reduced by 10
percent.
2012 IMC Performing Commercial Mechanical Inspection 164Workbook Page 123
Walking Though the Steps:
Length Alternative
2012 IMC Performing Commercial Mechanical Inspection 165Workbook Page 124
3' R
ISE
5-INCH DIAMETERDOUBLE-WALL CONNECTOR
CL
DOUBLE-WALLCONNECTOR
FROM 2ndCATEGORY IAPPLIANCE
HOT WATER BOILERFAN-ASSISTED82% EFFICIENT135,000 Btu/h
20 ftTOTALVENT
HEIGHT
Length Connector
A. Determine maximum allowable vent
connector length
▪ Use Table 504.3.2
▪ 5 inch (127 mm) connector diameter is 7 ½
feet (2286 mm).
225
2012 IMC Performing Commercial Mechanical Inspection 166Workbook Page 124
Length Connector
B. Determine absolute maximum allowable
vent connector length
▪ Use Section 503.10.8
▪ 5 inch (127 mm) connector diameter 20 feet
(6096 mm) [High Vent].
195
2012 IMC Performing Commercial Mechanical Inspection 167Workbook Page 125
Length Connector
C. Evaluate steps 1 and 2
▪ Apply the more restrictive criteria, or
▪ Apply connector length alternative provisions
of Section 504.3.3
30
2012 IMC Performing Commercial Mechanical Inspection 168Workbook Page 125
Length Connector
D. Apply provisions of Section 504.3.3
▪ Use Tables 504.3(2) and 504.3(1)
▪ Extend vent connector maximum length to 15 feet
(4572 mm)
▪ Apply 10 percent capacity reduction
▪ Maximum input capacity of 176,000 Btu/h (51 535 W)
▪ [176,000 x .90] = 158,400 Btu/h (46 381 W)
▪ 158,400 Btu > 135,000 Btu/h (46 381 W > 39 529 W)
▪ Boiler exceeds minimum required input of 59,000 Btu/h
(17 276 W) in Table 504.2(1)
2012 IMC Performing Commercial Mechanical Inspection 169
(A/B × C) + D
(2.5/5 × 30) + 195 =
1/2 × 30) + 195 =
15 + 195 = 210
Workbook Page 125
Offsets
2012 IMC Performing Commercial Mechanical Inspection 170Workbook Page 128
Step 10 - Seven Times Rule
▪ Flow area of vertical vent must not be larger
than seven times the area of the smallest
appliance vent connection.
IFGC Section 504.2.9
Workbook Page 1292012 IMC Performing Commercial Mechanical Inspection 171
Task 5: Inspect Appliance
Venting
1. Check sizing of category I appliance venting
systems. IFGC Section504.2.2.
2. Check sizing of venting systems for a single
appliance. IFGC Section 504.2.2.
3. Check minimum size.
IFGC Section 504.2.2 (1-5).
4. Check vent offsets.
IFGC 504.2.3.
2012 IMC Performing Commercial Mechanical Inspection 172Workbook Page 130-133
Task 5: Inspect Appliance
Venting
5. Check multiple input rate appliances.
IFGC 504.2.6.
6. Check chimney and vent locations.
IFGC 504.2.9.
7. Check liner system sizing.
IFGC 504.2.7.
8. Check vent area and diameter.
IFGC Section 504.2.8.
Workbook Page 130-1332012 IMC Performing Commercial Mechanical Inspection 173
Task 5: Inspect Appliance
Venting
9. Check table interpolation.
IFGC Table 504.3 (1) and 504.3 (2).
10.Check sizing of a venting system for two of
more appliances.
IFGC Table 504.3 (1) through 504.3 (7).
11.Check height and rise measurement.
IFGC Table 504.3 (1) through 504.3 (7).
12. Check vent fittings.
IFGC Section 504.3.9-504.2.9.1 .
Workbook Page 130-1332012 IMC Performing Commercial Mechanical Inspection 174
Table Interpolation
IFGC Table 504.2(1)
▪ Vent type is Type B from furnace
connection to terminal
▪ Input rating of draft hood furnace
= 210,000 Btu/h (61 545 W)
▪ Vertical design height of vent =
121/2 feet (3810 mm)
▪ Diameter of vent = 6 inches (152
mm)
▪ Length of lateral = 2 feet (610
mm)2012 IMC Performing Commercial Mechanical Inspection 175
Workbook Page 134
Table Interpolation
IFGC Table 504.2(1)
A. Find the maximum vent capacity (MAX)
at the first height entry greater than 121/2
feet (3810 mm), [i.e., 15 feet (4572 mm)].
225
B. Find the maximum vent capacity (MAX)
at the next height entry lower than 121/2
feet (3810 mm), [i.e., 10 feet (3048 mm)].
195
2012 IMC Performing Commercial Mechanical Inspection 176Workbook Page 134
Table Interpolation
IFGC Table 504.2(1)
C. Determine the difference between the two
maximum vent capacities.
330
D. Determine the maximum vent capacity for
a 121/2-foot-high (3810 mm) vent.
2012 IMC Performing Commercial Mechanical Inspection 177
(A/B × C) + D
(2.5/5 × 30) + 195
(1/2 × 30) + 195
15 + 195 = 210
Workbook Page 134
Sizing Type B Vent System
2012 IMC Performing Commercial Mechanical Inspection 178Workbook Page 137
Sizing Type B Vent System
A. Find each connector size:
a. Select correct table:
Table number: ____________________
b. Determine the least total height of vent and the rise for each
connector.
Vent height: ____________________
Water heater rise: ____________________
Furnace rise: ____________________
c. Determine the vent connector size per the applicable table:
Water heater: ____________________
Furnace: ____________________
2012 IMC Performing Commercial Mechanical Inspection 179
504.3(1)
15 feet (4572 mm)
1 foot (305 mm)
3 feet (914 mm)
4 inch (102 mm)
5 inch (127 mm)
Workbook Page 139
Sizing Type B Vent System
B. Find common vent size:
a. Determine the total Btu/h input:
Combined input rating: ____________________
b. Using the common vent portion of the same table
used
to size the connectors, determine the size of the
common vent.
Size of common vent: ____________________
2012 IMC Performing Commercial Mechanical Inspection 180
140,000 Btu/h (40,994 W)
5 inch (127 mm)
Workbook Page 139
Task 5: Inspect Appliance
Venting
13.Check vent terminations.
IFGC Section 503.6.4 and Table 503.6.4.
14.Check multistory installations.
IFGC Section 503.6.10.
15.Check direct-vent, integral vent, mechanical
vent and ventilation/ exhaust hood venting.
IFGC Section 505
Workbook Page 141-1522012 IMC Performing Commercial Mechanical Inspection 181
Gas Vent Termination
▪ Determine which diagram shows correct
vent termination requirement
2012 IMC Performing Commercial Mechanical Inspection 182
455'
6'
12
18
CorrectIncorrect,
[needs 7'6" (2286 mm)]
Workbook Page 144
Venting Systems
▪ Given the following information, size the
entire venting system.
▪ Water heater- 40,000 Btu/h (11,717 W)
▪ Natural Draft
▪ 3-inch (76 mm) Draft hood
▪ Furnace 80,000 Btu/h (23,425 W)
▪ Fan Assisted
▪ 4-inch (102 mm) Flue Collar
2012 IMC Performing Commercial Mechanical Inspection 183Workbook Page 145
Venting Systems
▪ Work the problem here.
A. A. Diameter for the water heater connector.
4 inches
B. Diameter for the furnace connector.
4 inches
C. Percent capacity reduction for common vent.
20 percent, Sections 504.3.5 and 505.3.6
2012 IMC Performing Commercial Mechanical Inspection 184Workbook Page 145
Venting Systems
▪ Work the problem here.
D. Diameter of common vent.
5 inches, (159,000 Btu/h ´ 0.80 = 127,200 Btu/h)
(46,557 W × 0.80 = 37,245.6 W)]
E. Maximum allowable horizontal connector length.
6 feet (1829 mm) or in accordance with Sections 504.3.2
and 503.10.9 the MAX Length allowed is 12.75' (3886 mm)
[75% × 17' (5182 mm) = 12.75 (75% × 5182 = 3886)]
2012 IMC Performing Commercial Mechanical Inspection 185Workbook Page 145
Venting Systems
▪ Work the problem here.
F. Maximum allowable length of common
vent offset.
7.5 (191 mm)
G. Is interpolation necessary?
No
2012 IMC Performing Commercial Mechanical Inspection 186Workbook Page 145
Sizing of Venting Systems
for Two or More Appliances
2012 IMC Performing Commercial Mechanical Inspection 187Workbook Page 148
Sizing of Venting Systems
for Two or More Appliances
▪ Determine the venting system sizing for
the two appliances.
▪ Find the size of the common vent based
on least total height and the combination
of connected appliances
2012 IMC Performing Commercial Mechanical Inspection 188Workbook Page 148
Sizing of Venting Systems
for Two or More Appliances
▪ Consider the system to have the following
characteristics:
▪ A two-appliance FAN + NAT system, combining a water
heater (NAT) equipped with a draft hood with a fan-
assisted Category I furnace (FAN).
▪ Single-wall pipe connectors are used.
▪ Vent height is 35 feet (10 668 mm).
▪ Furnace connector rise is 4 feet (1219 mm).
▪ Water heater connector rise is 2 feet (610 mm).
▪ Furnace input is 75,000 Btu/h (21,961 W).
▪ Water heater input is 42,000 Btu/h (12,298 W).
2012 IMC Performing Commercial Mechanical Inspection 189Workbook Page 141
Sizing of Venting Systems
for Two or More Appliances
A. Furnace Connector
Material:
Size:
B. Water Heater
Connector Material:
Size:
C. Common Vent Size:
2012 IMC Performing Commercial Mechanical Inspection 190
▪ Type B
▪ 4 inches, [Table 504.3(1)]
▪ Single-wall
▪ 4 inches, [Table 504.3(2)]
▪ 4 inches (102 mm) [10% reduction for
offset, 132,000 Btu/h × 0.9 = 118,800
Btu/h (38,651 W × 0.9 = 34,785.9 W)]
Workbook Page 149
Sizing of Venting Systems
for Two or More Appliances
D. Interpolation Necessary? No
E. Any Noted Violations?
2012 IMC Performing Commercial Mechanical Inspection 191Workbook Page 142
Common Vent Sizing For
Two or More Appliances
▪ Workbook page 143
▪ In groups of 3-4
▪ Answer the A through M
2012 IMC Performing Commercial Mechanical Inspection 192Workbook Page 150
Performing Inspections of
Exhaust Systems
Module 8
2012 IMC Performing Commercial Mechanical Inspection 193
Six Tasks
1. Inspect for required systems compliance.
IMC Section 502.
2. Inspect motors and fans.
IMC Section 503.
3. Inspect clothes dryer exhaust. IMC Section 504 and
IFGC Section 614.1.
4. Inspect commercial kitchen exhaust systems.
IMC Section 506 through 509.
5. Inspect hazardous exhaust systems.
IMC Section 510.
6. Inspect energy recovery ventilation systems.
IMC Section 514.
Workbook Page 1552012 IMC Performing Commercial Mechanical Inspection 194
Task 1: Inspect for Required
Systems Compliance
1. Check exhaust location.
IMC Section 501.3.1 and 501.3.1.1.
2. Check areas requiring exhaust systems.
IMC Section 501.1
3. Check for recirculation.
IMC Table 403.3.
4. Check termination points.
IMC Section 501.3.1.
Workbook Page 157-158
2012 IMC Performing Commercial Mechanical Inspection 195
Task 2: Inspect Motors and Fans
1. Check sizes.
IMC Section 503.1.
2. Check fan protection.
IMC Section 503.2.
3. Check fans in areas with corrosives.
IMC Section 503.4.
4. Check for required Fan Interlocks.
IMC Section 503
Workbook Page 1592012 IMC Performing Commercial Mechanical Inspection 196
Task 3: Inspect Clothes Dryer
Exhaust
1. Check installation.
IMC Section 504.1 and IFGC Section 614.
2. Check exhaust penetrations.
IMC Section 504.2 and IFGC Section 614.2.
3. Check exhaust installation.
IMC Section 504.4 and IFGC 614.4.
Workbook Page 160-1612012 IMC Performing Commercial Mechanical Inspection 197
Multiple Dryer Installation
2012 IMC Performing Commercial Mechanical Inspection 198Workbook Page 160-161
Task 4: Inspect Commercial
Kitchen Exhaust Systems
1. Check for the presence of exhaust systems where
required. IMC Section507.2, 507.2.1, 507.2.1.1 and
507.2.2
2. Check grease duct clearances.
IMC Section 506.3.6
3. Check grease duct enclosure.
IMC Section 506.3.11.1 through 506.3.11.4.
4. Check terminations through an exterior wall, if present.
IMC Section 506.3.3.12.2.
Workbook Page 162-1672012 IMC Performing Commercial Mechanical Inspection 199
Termination Through Exterior
Wall
2012 IMC Performing Commercial Mechanical Inspection 200
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm
Workbook Page 162-167
Task 4: Inspect Commercial
Kitchen Exhaust Systems
5. Check ducts.
IMC Section 506.1 through 506.3, 506.3.1,
506.3.1.1, 506.3.1.2 and 506.3.2.
6. Check type I hoods.
IMC Section 507.2.1.
7. Check type II hoods.
IMC Section 507.2.2.
8. Check type I and II materials.
IMC Section 507.4 and 507.5.
Workbook Page 162-1672012 IMC Performing Commercial Mechanical Inspection 201
Task 4: Inspect Commercial
Kitchen Exhaust Systems
9. Check capacity of the hoods.
IMC Section 507.13.
10.Check fuel burning appliances.
IMC Section 507.3.
11.Check commercial kitchen makeup air.
IMC Section 508.
12.Verify or observe the capture and containment
test.
IMC Section 507.16.1.
Workbook Page-162-1672012 IMC Performing Commercial Mechanical Inspection 202
COMMERCIAL COOKING
RECIRCULATING SYSTEM
▪ Self-contained system consisting of the exhaust
hood, the cooking equipment, the filters and the
fire suppression system. The system is
designed to capture cooking vapors and residue
generated from commercial cooking equipment.
The system removes contaminants from the
exhaust air an re-circulates the air to the space
from which it was withdrawn.
2012 IMC Performing Commercial Mechanical Inspection 203
COMMERCIAL COOKING
APPLIANCES
▪ Appliances used in a commercial food service
establishment for heating or cooking food and which
produce grease vapors, steam, fumes, smoke or odors
that are required to be removed through a local exhaust
ventilation system… For the purpose of this definition, a
food service establishment shall include any building or a
portion thereof used for the preparation and serving of
food.
2012 IMC Performing Commercial Mechanical Inspection 204
Backshelf Hood
A backshelf hood is also referred to as a low-proximity
hood, or as a sidewall hood where all mounted. It’s
front lower lip is low over the appliance(s) and is “set
back” from the front of the appliance(s). It is always
closed to the rear of the appliances by a panel where
free-standing, or by a panel or wall where wall mounted
and its height above the cooking surface varies. (This
style of hood can be constructed with partial end panels
to increase its effectiveness in capturing the effluent
generated by the cooling operation).
2012 IMC Performing Commercial Mechanical Inspection 205
Backshelf Hood
2012 IMC Performing Commercial Mechanical Inspection 206
Double Island Canopy Hood
▪ A double island canopy hood is placed over back
to back appliances or appliance lines. It is open
on all sides and overhangs both fronts and the
sides of the appliance(s). It could have a wall
panel between the backs of the appliances. (The
fact that exhaust air is drawn from both sides of
the double canopy to meet in the center causes
each side of this hood to emulate a wall canopy
hood, and thus it functions much the same with or
without an actual wall panel between the backs of
the appliances).
2012 IMC Performing Commercial Mechanical Inspection 207
Eyebrow Hood
▪ A eyebrow hood is mounted directly to the face
of an appliance, such as an oven and
dishwasher, above the opening(s) or door(s)
from which effluent is emitted, extending past
the sides and overhanging the front of the
opening to capture the effluent.
2012 IMC Performing Commercial Mechanical Inspection 208
Pass-over Hood
▪ A passover hood is a
free-standing form of
a backshelf hood
constructed low
enough to pass food
over the top.
2012 IMC Performing Commercial Mechanical Inspection 209
Single Island Canopy Hood
▪ A single island copy hood is
placed over a single appliance or
appliance line. It is open on all
sides and overhangs the front,
rear, and sides of the appliance(s).
A single island canopy is more
susceptible to cross drafts and
requires a greater exhaust air flow
than an equivalent sized wall-
mounted canopy to capture and
contain effluent generated by
cooling operations(s).
2012 IMC Performing Commercial Mechanical Inspection 210Workbook Page 162-167
Wall Canopy Hood
▪ A wall canopy exhaust hood is mounted
against a wall above a single appliance or
line of appliance(s), or it could be free-
standing with a back panel from the rear
of the appliances to the hood. It
overhangs the front and sides of the
appliance(s) on all open sides.
▪ The wall acts as a back panel, forcing the
makeup air to be drawn across the front of
the cooking equipment, thus increasing
the effectiveness of the hood to capture
and contain effluent generated by the
cooking operation(s).
2012 IMC Performing Commercial Mechanical Inspection 211Workbook Page 162-167
Canopy Hood - Elevation
2012 IMC Performing Commercial Mechanical Inspection 212
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm
Workbook Page 162-167
Back-To-Back Type Canopy
Hood
2012 IMC Performing Commercial Mechanical Inspection 213
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm
Workbook Page 162-167
Extra-Heavy-Duty Cooking
Appliance
▪ Extra heavy duty cooling appliances include
appliances utilizing solid fuel such as wood,
charcoal, briquettes and mesquite as the
primary source of heat for cooking.
2012 IMC Performing Commercial Mechanical Inspection 214
Heavy-Duty Cooling Appliance
▪ Heavy-duty cooling appliances include electric
under-fired broilers, electric chain (conveyor)
broilers, gas under-fired broilers, gas chain
(conveyor) broilers, gas open-burner ranges
(with or without oven), electric and gas wok
ranges and electric ad gas over-fired (upright)
broilers and salamanders.
2012 IMC Performing Commercial Mechanical Inspection 215
Light-Duty Cooking Appliances
▪ Light-duty cooling appliances include gas and
electric ovens (including standard, bake,
roasting, revolving, re-therm, convection,
combination convection/steamer, conveyor, deck
or deck-style pizza, and pastry), electric and gas
steam-jacketed kettles, electric and gas
compartment steamers (both pressure and
atmospheric) and electric and gas
cheesemelters.
2012 IMC Performing Commercial Mechanical Inspection 216
Medium-Duty Cooling Appliance
▪ Medium-duty cooling appliances include electric
discrete element ranges (with or without oven),
electric and gas hot top ranges, electric and gas
griddles, electric and gas double sided griddles,
electric and gas fryers (including open deep fat
fryers, donut fryers, kettle fryers and pressure
fryers), electric and gas pasta cookers, electric
and gas conveyor pizza ovens, electric and gas
tilting skillets (brasing pans) and electric and gas
rotisseries.
2012 IMC Performing Commercial Mechanical Inspection 217
Makeup Air Supplied to Hood
2012 IMC Performing Commercial Mechanical Inspection 218Workbook Page 162-167
Task 5: Inspect Hazardous
Exhaust System
1. Check for hazardous exhaust systems where
required.
IMC Section 510.2.
2. Check design.
IMC Section 510.3.
3. Check operation.
IMC Section 510.3.
Workbook Page 1682012 IMC Performing Commercial Mechanical Inspection 219
Task 6: Inspect Energy
Recovery Ventilation Systems
1. Check IECC compliance, if necessary.
IMC Section 514.1.
2. Check if installation is allowed.
IMC Section 514.2.
Workbook Page 1692012 IMC Performing Commercial Mechanical Inspection 220
Performing Inspections of
Ducts and Plenums
Module 9
2012 IMC Performing Commercial Mechanical Inspection 221
Six Tasks
1. Inspect egress
elements.
IMC Section 601.2.
2. Inspect plenums.
IMC Section 602.
3. Inspect duct
construction and
installation.
IMC Section 603.
4. Inspect insulation.
IMC Section 604.
5. Inspect smoke
detection systems
control.
IMC Section 606.
6. Inspect ducts and air
transfer openings.
IMC Section 607.
Workbook Page 1712012 IMC Performing Commercial Mechanical Inspection 222
Task 1: Inspect Egress Elements
1. Check air movement in egress elements.
IMC Section 601.2.
2. Check the corridor ceiling.
IMC Section 601.2.1.
3. Check the exit enclosure for compliance.
IMC Section 601.3.
4. Check for the air movement in egress
situations. IMC Section 601.2
Workbook Page 172-1732012 IMC Performing Commercial Mechanical Inspection 223
Task 2: Inspect Plenums
1. Check locations of supply, return, exhaust, relief and
ventilation air plenums.
IMC Section 602.1.
2. Check plenum construction.
IMC Section 602.2.
3. Check materials exposed within plenums.
IMC Section 602.2..1.
4. Check stud cavity and joist space plenums.
IMC Section 602.3.
5. Check for flood hazard.
IMC Section 602.4.
2012 IMC Performing Commercial Mechanical Inspection 224Workbook Page 174-175
Typical Floor/Ceiling Return and
Plenum
2012 IMC Performing Commercial Mechanical Inspection 225Workbook Page 174-175
Mechanical Room Used as
Return Air Plenum
2012 IMC Performing Commercial Mechanical Inspection 226Workbook Page 174-175
Acceptable Stud and Joist Space
Plenum Installation
2012 IMC Performing Commercial Mechanical Inspection 227Workbook Page 174-175
Unacceptable Stud and Joist
Space Plenum Installation
2012 IMC Performing Commercial Mechanical Inspection 228Workbook Page 174-175
Task 3: Inspect Duct
Construction and Installation
1. Check duct sizing.
IMC Section 603.2.
2. Check duct classification.
IMC Section 603.3.
3. Check metallic ducts.
IMC Section 603.4.
4. Check nonmetallic ducts.
IMC Section 603.5.
Workbook Page 176-1792012 IMC Performing Commercial Mechanical Inspection 229
Task 3: Inspect Duct
Construction and Installation
5. Check flexible air ducts and flexible air
connections.
IMC Section 603.6.
6. Check underground ducts.
IMC Section 603.8.
7. Check duct joints and supports.
IMC Section 603.9 and 603.10.
8. Check furnace connections.
IMC Section 603.11.
Workbook Page 176-1792012 IMC Performing Commercial Mechanical Inspection 230
Flexible Connector IMC Section 603.6.4
2012 IMC Performing Commercial Mechanical Inspection 231Workbook Page 176-179
Task 3: Inspect Duct
Construction and Installation
9. Check condensation.
IMC Section 603.12.
10.Check location.
IMC Section 603.14.
11.Check for protection.
IMC Section 603.15 and 603.16.
12.Check registers, grilles and diffusers.
IMC Section 603.17 (NEW ).
Workbook Page 176-1792012 IMC Performing Commercial Mechanical Inspection 232
Task 4: Inspect Insulation
1. Check for IECC compliance.
IMC Section 604.1.
2. Check surface temperature.
IMC Section 604.2.
3. Check coverings and linings.
IMC Section 604.3.
4. Check foam plastic insulation.
IMC Section 604.4.
Workbook Page 180-1822012 IMC Performing Commercial Mechanical Inspection 233
Duct Coverings IMC Section 604.3
2012 IMC Performing Commercial Mechanical Inspection 234Workbook Page 180-182
Task 4: Inspect Insulation
5. Check appliance testing and labeling.
IMC Section 604.5.
6. Check penetration of assemblies.
IMC Section 604.6.
7. Check identification.
IMC Section 604.7.
8. Check lining installation.
IMC Section 604.8.
Workbook Page 180-1822012 IMC Performing Commercial Mechanical Inspection 235
Task 4: Inspect Insulation
9. Check for thermal
continuity.
IMC Section 604.9.
10.Check service
openings.
IMC Section 604.10.
11.Check vapor
retarders.
IMC Section 604.11.
12.Check weatherproof
barriers.
IMC Section 604.12.
13.Check internal
insulation.
IMC Section 604.13.
Workbook Page 180-1822012 IMC Performing Commercial Mechanical Inspection 236
Task 5: Inspect Smoke Detection
Systems Control
1. Check that required controls are present.
IMC Section 606.1.
2. Check location of controls.
IMC Section 606.2.1 – 606.2.3.
3. Check installations.
IMC Section 606.3.
4. Check controls operation.
IMC Section 606.4.
Workbook Page 183-1842012 IMC Performing Commercial Mechanical Inspection 237
Duct Smoke Detectors
2012 IMC Performing Commercial Mechanical Inspection 238Workbook Page 183-184
Return Riser
2012 IMC Performing Commercial Mechanical Inspection 239Workbook Page 183-184
Task 6: Inspect Ducts and Air
Transfer Openings
1. Check installation.
IMC Section 607.2.
2. Verify damper
testing and ratings.
IMC Section 607.3
and 607.3.1.
3. Check location
requirements.
IMC Section 607.5.
4. Check horizontal
assemblies.
IMC Section 607.6.
5. Check Membrane
penetrations.
IMC Section 607.6.2.
6. Check flexible ducts
and air connectors.
IMC Section 607.7.
Workbook Page 185-1862012 IMC Performing Commercial Mechanical Inspection 240
Performing Refrigeration
Inspections
Module 10
2012 IMC Performing Commercial Mechanical Inspection 241
Three Tasks
▪ Inspect for general requirements compliance.
IMC Section 1102.1.
▪ Inspect classification.
IMC Section 1102.2 and Table 1103.1.
▪ Inspect machinery room.
IMC Section 1104.2.
Workbook Page 1872012 IMC Performing Commercial Mechanical Inspection 242
Task 1: Inspect for General
Requirements Compliance
1. Check factory-built equipment and appliances.
IMC Section 1101.2.
2. Check for protection.
IMC Section 1101.3.
3. Check water connection.
IMC Section 1101.4.
4. Check fuel gas connection.
IMC Section 1101.5.
Workbook Page 188-1892012 IMC Performing Commercial Mechanical Inspection 243
Task 1: Inspect for General
Requirements Compliance (cont)
5. Check for changes in refrigerant type.
IMC Section 1101.8.
6. Looking for access port caps. IMC Section
1101.10 (NEW).
7. Verify field test. IMC Section 1108.
Workbook Page 188-1892012 IMC Performing Commercial Mechanical Inspection 244
Task 2: Determine Classification
1. Determine the refrigeration system’s classification.
IMC Section 1102.1 and 1103.1.
2. Determine the refrigerant classification.
IMC Section 1102.2 and Table 1103.1.
3. Determine the maximum allowable quantity of
refrigerant.
IMC Table1103.1.
4. Determine the system enclosure requirements.
IMC Section 1103.3, 1103.3.1 and 1102.3.2.
5. Check refrigeration equipment location and installation.
IMC Section 1105 and 1106.
Workbook Page 190-1952012 IMC Performing Commercial Mechanical Inspection 245
Low-Probability SystemsIMC Section 1103.3.1
2012 IMC Performing Commercial Mechanical Inspection 246Workbook Page 190-195
High-Probability Systems IMC Section 1103.3.2
2012 IMC Performing Commercial Mechanical Inspection 247Workbook Page 190-195
Task 3: Inspect Machinery Room
1. Check refrigerant
detector.
IMC Section 1105.3.
2. Check fuel-burning
appliances.
IMC Section 1105.5.
3. Check rate for
normal ventilation.
IMC Section 1105.6.
4. Check for
compliance with
special
requirements.
IMC Section 1106.
5. Refrigerant piping.
IMC Section 1107.
Workbook Page 196-1972012 IMC Performing Commercial Mechanical Inspection 248
Gas Piping Installations
Module 11
2012 IMC Performing Commercial Mechanical Inspection 249
Five Tasks
1. Inspect for proper identification.
IFGC Section 401.5.
2. Review gas piping system plan.
3. Inspect piping materials.
IFGC Section 403.
4. Inspect piping system installation.
IFGC Section 404.
5. Inspect gas flow controls.
IFGC Section 410.
Workbook Page 1992012 IMC Performing Commercial Mechanical Inspection 250
Task 1: Inspect for Proper
Identification
1. Check exposed gas piping. IFGC Section
403.8.
2. Check multiple meter installations. IFGC
Section 401.7.
Workbook Page 2002012 IMC Performing Commercial Mechanical Inspection 251
Task 2: Review Gas Piping
System Plan
1. Determine maximum gas demand.
IFGC Section 402.2.
2. Determine length to most remote outlet.
IFGC Section 402.4.1 and 402.4.2.
3. Select the correct table.
IFGC Table 402.4 (1)-(35).
4. Locate gas-demand figures.
IFGC Table 402.4 (1)-(35).
5. Locate nominal size of pipe required.
IFGC Table 402.4 (1)-(35).
Workbook Page 201-2032012 IMC Performing Commercial Mechanical Inspection 252
A Gas Piping System Plan
2012 IMC Performing Commercial Mechanical Inspection 253Workbook Page 201-203
Gas System Sizing Problem
2012 IMC Performing Commercial Mechanical Inspection 254
Outlet B40-gal Water Heater45,000 Btu/hr Outlet AClothes Dryer20,000 Btu/hr
Point ofDelivery Outlet C Range73,000 Btu/hr
Outlet DFurnace133,000 Btu/hr
15 ft15 ft20 ft
10 ft
25 ft
12 ft
5 ft 5 ftSection 4 Section 3 Section 2 15 ftSec tion 1Section 5
Outlet B40-gal Water Heater45,000 Btu/hr Outlet AClothes Dryer20,000 Btu/hr
Point ofDelivery Outlet C Range73,000 Btu/hr
Outlet DFurnace133,000 Btu/hr
15 ft15 ft20 ft
10 ft
25 ft
12 ft
5 ft 5 ftSection 4 Section 3 Section 2 15 ftSec tion 1Section 5
Outlet B40-gal Water Heater45,000 Btu/hr Outlet AClothes Dryer20,000 Btu/hr
Point ofDelivery Outlet C Range73,000 Btu/hr
Outlet DFurnace133,000 Btu/hr
15 ft15 ft20 ft
10 ft
25 ft
12 ft
5 ft 5 ftSection 4 Section 3 Section 2 15 ftSec tion 1Section 5
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm
Workbook Page 205
Outlet B40-gal Water Heater
45,000 Btu/hr
Outlet AClothes Dryer20,000 Btu/hr
Point ofDelivery
Outlet C Range73,000 Btu/hr
Outlet DFurnace
133,000 Btu/hr
15 ft15 ft
20 ft
10 ft
25 ft
12 ft
5 ft 5 ft
Section 4 Section 3
Section 215 ft
Sectio
n 1
Section 5
Gas System Sizing Problem
1. Determine maximum gas demand:
Outlet A: 20 cfh (0.57m3/hr)
Outlet B: 45 cfh (1.27m3/hr)
Outlet C: 73 cfh (2.07m3/hr)
Outlet D: 133 cfh (3.76m3/hr)
Maximum gas demand: 271 cfh (7.86m3/hr)
2012 IMC Performing Commercial Mechanical Inspection 255Workbook Page 205
Gas System Sizing Problem
2. Determine length to the most remote
outlet:
Section 1: 15 ft. (4572 mm)
Section 2: 25 ft. (7620 mm)
Section 3: 5 ft. (1524 mm)
Section 4: 5 ft. (1524 mm)
Section 5: 30 ft. (9144 mm)
Total pipe length to most remote outlet: 80 ft.
(24 384 mm)
2012 IMC Performing Commercial Mechanical Inspection 256Workbook Page 206
Gas System Sizing Problem
3. Select applicable table:
Specific gravity: 0.60
Gas pressure: 10 IN WC (254 mm)
Pressure drop: 0.5 IN WC (12.7 mm)
Type of material: Steel Pipe
Special conditions: NA
Table Used: 402.4(2)
Table 402.4(2)
2012 IMC Performing Commercial Mechanical Inspection 257Workbook Page 206
Gas System Sizing Problem
4. Locate gas demand figures:
▪ Horizontal row showing length of piping
▪ Indicates length from point of delivery to most
remote outlet
▪ If not exact, use next longer distance
▪ Use this row for all gas demand figures
2012 IMC Performing Commercial Mechanical Inspection 258Workbook Page 206
Gas System Sizing Problem
5. Locate nominal size of pipe required:▪ Outlet C:
▪ 73 cfh requires 3/4 inch pipe
▪ (2.07 m3/hr requires 19.1 mm)
▪ Outlet D:
▪ 133 cfh requires 1 inch pipe
▪ (3.76 m3/hr requires 25.4mm)
▪ Pipe Section 4 (A,B,C):
▪ 138 cfh requires 1 inch pipe
▪ (3.91 m3/hr requires 25.4mm)
▪ Pipe Section 5 (A,B,C,D):
▪ 271 cfh requires 1 ¼ inch pipe
▪ (7.67 m3/hr requires 31.8mm)
2012 IMC Performing Commercial Mechanical Inspection 259Workbook Page 206
Branch Length Method
▪ Determine the size of gas piping sections
2012 IMC Performing Commercial Mechanical Inspection 260Workbook Page 207
Branch Length Method
2012 IMC Performing Commercial Mechanical Inspection 261
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm
Workbook Page 207
GAS GRILL
20 MBH
CSST
20’ F
RANGE
60 MBH WATER
HEATER
40 MBH
FURNACE 75
MBH
CLOTHES DRYER 35
MBH (MBH = 1,000 Btu/h)
SCHEDULE 40 STEEL
TRUNKLINE
LONGEST RUN
15’J 15’I 15’G
H 20’
POINT OF
DELIVERY
SPECIFIC
GRAVITY
0.60
A
10’
B
10’
D15’
E5’
C25’
ALL BRANCHES
CSST
9” WC
PRESSURE
Branch Length Method
1. Determine the size of trunk line sections
▪ Determine load for each section of pipe
▪ A = 230 MBH
▪ B = 170 MBH
▪ C = 135 MBH
▪ D = 95 MBH
▪ E = 20 MBH
▪ Determine the table to use = 402.4(2)
▪ Because longest run length of pipe is between
rows, use next higher row.
2012 IMC Performing Commercial Mechanical Inspection 262Workbook Page 208
Branch Length Method
▪ Determine the size of trunk line sections
▪ Determine size for each section of pipe
▪ A = 1 ¼ inch (31.8 mm)
▪ B = 1 inch (25.4 mm)
▪ C = 1 inch (25.4 mm)
▪ D = ¾ inch (19.1 mm)
▪ E = ½ inch (9.5 mm)
2012 IMC Performing Commercial Mechanical Inspection 263Workbook Page 208
Check Your Learning:
Answers
A. Determine the load for the following
branch sections
▪ Section F: 20 cfh (0.71 m3/hr)
▪ Section G: 60 cfh (1.7 m3/hr)
▪ Section H: 35 cfh (0.99 m3/hr)
▪ Section I: 40 cfh (1.13 m3/hr)
▪ Section J: 75 cfh (2.12 m3/hr)
2012 IMC Performing Commercial Mechanical Inspection 264Workbook Page 211
Check Your Learning:
Answers
B. Determine the length for each branch
▪ Section F: 85 ft. (25 908 mm)
▪ Section G: 25 ft. (7620 mm)
▪ Section H: 40 ft. (12 192 mm)
▪ Section I: 60 ft. (18 288 mm)
▪ Section J: 75 ft. (22 860 mm)
C. Determine the table to use
▪ Table 402.4(15)
2012 IMC Performing Commercial Mechanical Inspection 265Workbook Page 211
Check Your Learning:
Answers
D. Determine the size for each section of gas pipe.
2012 IMC Performing Commercial Mechanical Inspection 266
Pipe Section Length (ft.) Load (MBH) Size
F 85 20 18
G 25 60 19
H 40 35 18
I 60 40 23
J 75 75 30
Workbook Page 201
Hybrid Pressure System
Sizing
9 INCHES
WC
METER
SERVICE
REGULATOR
5 PSIG
A
90’
SCHEDULE 40 STEEL PIPING THROUGHOUT
RTU
1
200 MBH
10’ B
“POUNDS-TO-INCHES” REGULATORS
10’ D
RTU
2150 MBH
I
20’
F
40’
C
75’
RTU
3
RTU
4
H 15’
J 15’
E 25’
10’ G
125 MBH
150 MBH
9 INCHES
WC
2012 IMC Performing Commercial Mechanical Inspection 267Workbook Page 212
Parallel System Practice
2012 IMC Performing Commercial Mechanical Inspection 268Workbook Page 215
Check Your Learning:
Answers
▪ Required Size (CSST)
A 37
B 25
C 19
D 23
E 23
F 18
G 18
2012 IMC Performing Commercial Mechanical Inspection 269Workbook Page 215
Medium Pressure System
2012 IMC Performing Commercial Mechanical Inspection 270Workbook Page 217
Medium Pressure System
▪ Required Size (CSST)
A 18
B 15
C 13
D 13
E 15
F 13
G 13
2012 IMC Performing Commercial Mechanical Inspection 271Workbook Page 217
Branch Length Method
2012 IMC Performing Commercial Mechanical Inspection 272Workbook Page 221
Branch Length Method
▪ Required Size (Schedule
40)
▪ A 1 ¼” (31.8 mm)
▪ B 1 ¼” (31.8 mm)
▪ C 1” (25.4 mm)
▪ D 1” (25.4 mm)
▪ E ¾” (19.1 mm)
▪ F ¾” (19.1 mm)
▪ G 1/2” (12.7 mm)
2012 IMC Performing Commercial Mechanical Inspection 273
• Required Size (CSST)
– H 13
– I 23
– J 15
– K 18
– L 15
– M 18
– N 13
Workbook Page 221
2012 IMC Performing Commercial Mechanical Inspection 274Workbook Page 222
Task 3: Inspect Piping Materials
1. Check corrugated stainless steel tubing.
IFGC Section 403.5.4.
2. Check plastic tubing.
IFGC Section 403.11.
3. Check copper tubing.
IFGC Section 403.5.2.
4. Check protective coating and wrapping.
IFGC Section 403.8.
5. Check number and length of threads.
IFGC Section 403.9.
Workbook Page 223-2252012 IMC Performing Commercial Mechanical Inspection 275
Task 4: Inspect Piping System
Installation
1. Check prohibited location.
IFGC Section 404.3.
2. Check piping in concealed locations.
IFGC Section 404.5.
3. Check piping through foundation walls is prohibited,
underground penetration prohibited.
IFGC Section 404.6.
4. Check protection against physical damage.
IFGC Section 404.7.
5. Check piping in solid floors.
IFGC Section 404.8.
Workbook Page 226-2272012 IMC Performing Commercial Mechanical Inspection 276
Piping Through Foundation Wall
2012 IMC Performing Commercial Mechanical Inspection 277Workbook Page 226-227
Alternative Piping Through Solid
Floors
2012 IMC Performing Commercial Mechanical Inspection 278Workbook Page 226-227
Task 4: Inspect Piping System
Installation
6. Check minimum burial depth.
IFGC Section 404.12.
7. Check individual outdoor appliances.
IFGC Section 404.12.1.
8. Check inspection, testing and purging.
IFGC Section 406.
9. Check appliance isolation.
IFGC Section 406.3.2.
10.Inspect gas flow control.
IFGC Section 410.
Workbook Page 228-230
2012 IMC Performing Commercial Mechanical
Inspection 279
Gas Flow Controls
2012 IMC Performing Commercial Mechanical Inspection 280Workbook Page 228-230
Gas Flow Controls
2012 IMC Performing Commercial Mechanical Inspection 281Workbook Page 228-230
Gas Pressure Regulator
2012 IMC Performing Commercial Mechanical Inspection 282Workbook Page 228-230
Task 5: Inspect Gas Flow
Controls
1. Check MP regulators.
IFGC Section 410.2.
2. Check venting regulators.
IFGC Section 410.3.
3. Check appliance connections.
IFGC Section 411.1.
4. Check protection from damage.
IFGC Section 411.1.2.
5. Check movable appliances.
IFGC Section 411.1.4.
Workbook Page 231-2332012 IMC Performing Commercial Mechanical Inspection 283
284
International Code Council is a Registered Provider with The American
Institute of Architects Continuing Education Systems. Credit earned on
completion of this program will be reported to CES Records for AIA
members. Certificates of Completion for non-AIA members are available on
request.
This program is registered with the AIA/CES for continuing professional
education. As such, it does not include content that may be deemed or
construed to be an approval or endorsement by the AIA of any material of
construction or any method or manner of handling, using, distributing, or
dealing in any material or product. Questions related to specific materials,
methods, and services will be addressed at the conclusion of this
presentation.
2012 IMC Performing Commercial Mechanical Inspection
2012 IMC Performing
Commercial Mechanical
Inspection
285
Copyright Materials
This presentation is protected by US and
International Copyright laws. Reproduction,
distribution, display and use of the
presentation without written permission of the
speaker is prohibited.
© International Code Council 2011
Thank you for participating
To schedule a seminar, contact:
The ICC Training & Education Department
1-888-ICC-SAFE (422-7233) Ext. 33818
or
E-mail: icctraining@iccsafe.org
2012 IMC Performing Commercial Mechanical Inspection 286
Recommended