2012 IMC Performing Commercial Mechanical Inspections · 2019-11-06 · 2012 IMC Performing Commercial Mechanical Inspections Based Primarily on the 2012 International Mechanical

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.

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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


Overview

▪ Performing Ventilation Inspections

▪ Performing Inspections of Combustion Air

Provisions (Gas) and NonGas

▪ Performing Venting Systems Inspections

▪ Performing Inspections of Exhaust

Systems


Overview

▪ Performing Inspections of Ducts and

Plenums

▪ Performing Refrigeration Inspections

▪ Performing Inspections of Gas Piping

Installations


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


Performing Required General

Inspections

1. Check underground installations.

IMC and IFGC Section 107.2

2. Check rough-in components.


3. Perform the final inspection.


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.


3. Retest failures.



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


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?


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


From IMC

Table 308.6

and IFGC

Table 308.2

Reduced Clearance to Combustibles

Using Protective Assemblies


Performing Protection of

Structure InspectionsIMC and IFGC Section 302

▪ Four tasks:

1. Inspect structural safety.


2. Inspect cutting, notching and boring in wood

framing.


3. Inspect alterations to trusses.


4. Inspect cutting, notching and boring in steel framing.

IMC and IFCGC Section 302.5

Workbook Page 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.


3. Check protection of penetrations of floor/ceiling

assemblies and fire-resistance-rated

assemblies.

IMC Section and IFGC 302.2


Task 2: Inspect Cutting, Notching

and Boring in Wood Framing

1. Check joist notching.


2. Check stud cutting and notching.


3. Check bored holes.


4. Check engineered wood products.



Limitations for Cutting, Notching

and Bored Holes


Bored Hole Limitations


Task 3: Inspect Alterations to

Trusses

1. Check truss condition.


2. Check for alterations that add to loads of

trusses.



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


cold-formed steel framing.



nonstructural cold-formed steel wall framing.



Performing Appliance

Inspections

Module 2


Performing Appliance Location

InspectionsIMC and IFGC Section 303

▪ Three tasks:

1. Inspect general locations.

IM and IFGC Section 303.1

2. Inspect indoor locations.


3. Inspect outdoor locations.



Task 1: Inspect General

Locations

1. Check for hazardous locations.


2. Check for prohibited locations.


3. Check for protection from damage.



Task 2: Inspect Indoor Locations

1. Check room volume.


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


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



Public GarageIMC Section 304.6/IFGC Section 304.5


Public 8 ft. Min. 1 ft. above higher than the tallest vehicle.

Private GarageIMC Section 304.6/IFGC Section 304.5


Performing Appliance Access

Inspections ▪ Five tasks:

1. Inspect appliances in rooms.


2. Inspect appliances in attics.


3. Inspect appliances under floors.


4. Inspect equipment and appliances on roofs and

elevated structures.


5. Inspect appliances on sloped roofs.



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


Task 2: Inspect Appliances in

Attics IMC and IFGC Section 306.3


requirements.


2. Check for compliance with electrical

requirements.



Attic Location Requirements


Task 3: Inspect Appliances

Under Floors IMC and IFGC Section 306.4


requirements.


2. Check for compliance with electrical

requirements.



Task 4: Inspect Equipment and Appliances on

Roofs and Elevated Structures

1. Check for permanent approved means of

access.


2. Check for obstacles to access and access

safety.


3. Check permanent ladders.


4. Check catwalks.



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.


Access Platform On Roof


Guards



Installation Inspections

▪ Eight tasks:

1. Examine installation information.


2. Resolve conflicts (if applicable).


3. Inspect installations having ignition sources.


4. Inspect ventilation for hydrogen generating and

refueling operations.

IMC Section 304.5.1 /IFGC Section 703.1



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


8. Verify clearance from grade.



Task 1: Examine Installation

Information

1. Check the manufacturer’s installation

instructions.


2. Check the applicable IMC/IFGC code sections.

IMC Section 304.1/

IFGC Section 305.1

3. Compare the two.


Task 2: Resolve ConflictsIMC Section 304.2 or IFGC Section 305.1

1. Identify if installation information contains

conflicts.


2. Resolve the conflict.



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. .


2. Check the elevation of ignition source.



Oil-fired Water Heater Installation

in a Hazardous Area


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


Task 5: Inspect Garages IMC Section 304.6 or IFGC Section 305.4

1. Check public garages.


2. Check private garages.



Appliance Installation in a Public

Garage


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.



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.


Guards


Guards – Plan View


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.


Performing Inspections of Fireplaces

and Solid Fuel Appliances

Module 3


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


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


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


Typical Factory-build Fireplace

With Hearth


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


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



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



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



Condensate Piping IMC Section 307/IFGC Section 307

▪ Three tasks:

▪ Inspect fuel-burning appliances.


▪ 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.



Task 1: Inspect Fuel Burning

Appliance Drain

1. Check collection and discharge.

IMC Section 307.1/IFGC Section 307.2.

2. Check horizontal slope.


3. Check for corrosion resistance.


4. Check drain size.

IMC Section 307.2.2 and Table 307.2.2/IFGC

Section 307.3.


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.


3. Check condensate waste and drain line size.

IMC Section 307.2.2and Table 307.2.2/IFGC

Section .


Task 3: Inspect Evaporators and

Cooling Coils

1. Check condensate disposal point.

IMC Section 307.2.1

2. Check auxiliary and secondary drain systems.


3. Check traps.



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.


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 .


Task 2: Inspect Fuel Gas PipingIFGC Chapter 4

1. Identify piping and components owned by

the gas utility company.

2. Check materials and components.


4. Check sizing of gas piping.

5. Check gas flow controls.

6. Check appliance connections.


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


Performing Ventilation

Inspections

Module 5


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


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.


Air Intake Opening Locations


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).


Economizer


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.


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.


5. Check transfer air, if

being utilized.


6. Check common

ventilation systems.

IMC Section 403.2.3


Table

403.3

Required

Outdoor

Ventilation

Air


Table 403.3

Required

Outdoor

Ventilation

Air


Table 403.3

Required

Outdoor

Ventilation

Air


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.




▪ 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



▪ 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




▪ 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




▪ 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).





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



▪ 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.


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.




▪ 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.




▪ 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.




▪ 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 =


Workbook Page 87-96



▪ 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






▪ 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





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).





▪ 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



▪ 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.


▪ Zp =Voz

▪ Vpz

▪ Zone 1: Zp = 775 cfm/8,100 cfm = 0.096

▪ Zone 2: Zp = 194 cfm/780 cfm = 0.25




▪ 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.




▪ 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:




▪ 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.



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




▪ 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




▪ 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




▪ 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).




▪ 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:




▪ 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.




▪ 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.




▪ 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.




▪ 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)



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.






▪ 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


0.12 cfm/ft2


0.06 cfm/ft2



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)


▪ Zone 3: Vbz (Zone 3) = 10 cfm/person (30 people) + 0.12 cfm/sq ft

(1,200 ft2)


▪ Zone 4: Vbz (Zone 4) = 0 cfm/person (0 people) + 0.06 cfm/sq ft

(750 ft2)






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).





▪ 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










▪ 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






▪ 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




▪ 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.




▪ 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.




▪ 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.




▪ 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.




▪ 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




▪ 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)




▪ 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).


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.


An Energy-conserving

Alternative to Natural Ventilation



Combustion Air provisions (Gas)

and NonGas Fuel Installation

Module 6


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.


Five Parts (cont.)

▪ Performing inspection of mechanical combustion

air supply.

Mechanical Combustion Air Supply.

IFGC Section 304.9


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


All Air from Inside the Building


Performing Inspections for

Outdoor Air (Gas) Provisions

▪ Three tasks:

1. Inspect air opening dimensions.

IFGC Section 304.6.

2. Inspect two-permanent-opening method.


3. Inspect one-permanent-opening method.



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.


Task 2: Inspect Two-Permanent-

Opening Method

▪ Check opening location.

IFGC Section304.5.3.

▪ Check communication to the outdoors.

IFGC Section 304.6


Inlet Air from Ventilated Crawl Space

and Outlet Air to Ventilated Attic


Inlet Air from Inlet Duct and

Outlet Air to Ventilated Attic



Workbook Page 102

All Air from Outdoors


Task 3: Inspect One-Permanent-

Opening Method

1. Check opening location.


2. Combination Indoor and Outdoor Combustion

air. IFGC 304.7

3. Check communication to the outdoors.


4. Check clearances.



One-Permanent-Opening Method, All

Air from the Outdoors



Combination Indoor/Outdoor Air

▪ Three tasks:

1. Inspect indoor openings.


2. Inspect outdoor opening location.


3. Inspect outdoor opening(s) size.



Task 1: Inspect Indoor Openings

1. Check for the minimum free area.


2. Check opening locations.



Task 2: Inspect Outdoor Opening

Location

▪ Check opening locations.

IFGC Section 304.7.3 and 304.10


Task 3: Inspect Outdoor

Opening(s) Size

▪ Check outdoor opening sizes.

IFGC Section 304.6, 304.6.1 and 304.6.2.


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.


Task 1: Inspect Engineered

Systems

▪ Verify that engineered systems meet the intent

of the code.

IFGC Section 304.8.


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.


4. Check combined combustion air and ventilation

air system. IFGC Section 304.9.3.


Mechanical Combustion Air

Supply System IFGC 304.9


Mechanical Combustion Makeup

Air Supply System IFGC 304.9


Mechanical Combustion Makeup

Air Supply System IFGC 304.9


Performing Venting

Systems Inspections

Module 7


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.


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.


Appliance Categories


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.


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


Decorative ShroudsGas Vents IFGC 503.6.4.1, Chimney IFGC 503.5.4


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


Vent System Performance

Factors


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.


Connectors


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



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


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).


9. Check for connector capacity reduction.


10.Check seven times rule.



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.


Walking Though the Steps:

Length Alternative


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


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


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


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)


(A/B × C) + D

(2.5/5 × 30) + 195 =

1/2 × 30) + 195 =

15 + 195 = 210

Workbook Page 125

Offsets


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


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.



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.




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 .


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


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.


(A/B × C) + D

(2.5/5 × 30) + 195

(1/2 × 30) + 195

15 + 195 = 210

Workbook Page 134

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: ____________________


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


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: ____________________


140,000 Btu/h (40,994 W)

5 inch (127 mm)

Workbook Page 139


Venting

13.Check vent terminations.

IFGC Section 503.6.4 and Table 503.6.4.

14.Check multistory installations.


15.Check direct-vent, integral vent, mechanical

vent and ventilation/ exhaust hood venting.

IFGC Section 505


Gas Vent Termination

▪ Determine which diagram shows correct

vent termination requirement


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


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


Venting Systems


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)]


Venting Systems


F. Maximum allowable length of common

vent offset.

7.5 (191 mm)

G. Is interpolation necessary?

No


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




▪ 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).




A. Furnace Connector

Material:

Size:

B. Water Heater

Connector Material:

Size:

C. Common Vent Size:


▪ 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



D. Interpolation Necessary? No

E. Any Noted Violations?


Common Vent Sizing For

Two or More Appliances

▪ Workbook page 143

▪ In groups of 3-4

▪ Answer the A through M



Exhaust Systems

Module 8


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.


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.


Workbook Page 157-158


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


Task 3: Inspect Clothes Dryer

Exhaust


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.


Multiple Dryer Installation


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.


Termination Through Exterior

Wall






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.


7. Check type II hoods.


8. Check type I and II materials.

IMC Section 507.4 and 507.5.




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.


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.


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.


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).


Backshelf Hood


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).


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.


Pass-over Hood

▪ A passover hood is a

free-standing form of

a backshelf hood

constructed low

enough to pass food

over the top.


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).


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).


Canopy Hood - Elevation




Back-To-Back Type Canopy

Hood




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.


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.


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.


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.


Makeup Air Supplied to Hood


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.


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.



Ducts and Plenums

Module 9


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.


Task 1: Inspect Egress Elements

1. Check air movement in egress elements.

IMC Section 601.2.

2. Check the corridor ceiling.


3. Check the exit enclosure for compliance.

IMC Section 601.3.

4. Check for the air movement in egress

situations. IMC Section 601.2


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.


Typical Floor/Ceiling Return and

Plenum


Mechanical Room Used as

Return Air Plenum


Acceptable Stud and Joist Space

Plenum Installation


Unacceptable Stud and Joist

Space Plenum Installation


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.




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.


8. Check furnace connections.

IMC Section 603.11.


Flexible Connector IMC Section 603.6.4




9. Check condensation.

IMC Section 603.12.

10.Check location.

IMC Section 603.14.

11.Check for protection.


12.Check registers, grilles and diffusers.

IMC Section 603.17 (NEW ).


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.


Duct Coverings IMC Section 604.3



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.



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.


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.


Duct Smoke Detectors


Return Riser


Task 6: Inspect Ducts and Air

Transfer Openings


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.


6. Check flexible ducts

and air connectors.

IMC Section 607.7.


Performing Refrigeration

Inspections

Module 10


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.



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.



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.


Task 2: Determine Classification

1. Determine the refrigeration system’s classification.


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.


Low-Probability SystemsIMC Section 1103.3.1


High-Probability Systems IMC Section 1103.3.2


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.


Gas Piping Installations

Module 11


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.


Task 1: Inspect for Proper

Identification

1. Check exposed gas piping. IFGC Section

403.8.

2. Check multiple meter installations. IFGC

Section 401.7.


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).


A Gas Piping System Plan


Gas System Sizing Problem


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




15 ft15 ft20 ft

10 ft

25 ft

12 ft





15 ft15 ft20 ft

10 ft

25 ft

12 ft



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


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)



2. Determine length to the most remote

outlet:

Section 1: 15 ft. (4572 mm)





Total pipe length to most remote outlet: 80 ft.

(24 384 mm)



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)



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



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


▪ Pipe Section 5 (A,B,C,D):

▪ 271 cfh requires 1 ¼ inch pipe



Branch Length Method

▪ Determine the size of gas piping sections





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


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.



▪ 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)


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)



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)



Answers

D. Determine the size for each section of gas pipe.


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


Parallel System Practice



Answers

▪ Required Size (CSST)

A 37

B 25

C 19

D 23

E 23

F 18

G 18


Medium Pressure System


Medium Pressure System

▪ Required Size (CSST)

A 18

B 15

C 13

D 13

E 15

F 13

G 13





▪ 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)


• Required Size (CSST)

– H 13

– I 23

– J 15

– K 18

– L 15

– M 18

– N 13

Workbook Page 221


Task 3: Inspect Piping Materials

1. Check corrugated stainless steel tubing.


2. Check plastic tubing.


3. Check copper tubing.


4. Check protective coating and wrapping.

IFGC Section 403.8.

5. Check number and length of threads.

IFGC Section 403.9.


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.


Piping Through Foundation Wall


Alternative Piping Through Solid

Floors


Task 4: Inspect Piping System

Installation

6. Check minimum burial depth.


7. Check individual outdoor appliances.


8. Check inspection, testing and purging.

IFGC Section 406.

9. Check appliance isolation.


10.Inspect gas flow control.

IFGC Section 410.


2012 IMC Performing Commercial Mechanical

Inspection 279

Gas Flow Controls


Gas Flow Controls


Gas Pressure Regulator


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.


5. Check movable appliances.



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

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2012 IMC Performing Commercial Mechanical Inspections · 2019-11-06 · 2012 IMC Performing Commercial Mechanical Inspections Based Primarily on the 2012 International Mechanical