Upload
phungcong
View
224
Download
0
Embed Size (px)
Citation preview
Applying the latest version of the National Ventilation Standard
Heyoka Solutions, LLC
Paul H. Raymer
All Contents Copyright 2013 by Heyoka Solutions, LLC. ALL RIGHTS RESERVED. Any use of materials, photographs, drawings, depictions or content, including reproduction, modification, distribution or republication, without the prior written consent of Heyoka Solutions, LLC, is strictly prohibited. Copyright infringement is a violation of federal law subject to criminal and civil penalties.
©Heyoka Solutions, LLC 2013
Located on Cape Cod, Massachusetts;
Member ASHRAE 62.2 SSPC
HERS Rater, BPI Analyst, Envelope, Heating, and AC/Heat Pump Certified;
Certified IREC/ANSI Assessor;
Author of the Residential Ventilation Handbook
©Heyoka Solutions, LLC 2012
©Heyoka Solutions, LLC 2012
One cubic foot of air (cfm) moves into a house only if one
cubic foot of air moves out of the house.
1cfm in = 1 cfm out
©Heyoka Solutions, LLC 2012
Air always flows from areas of higher pressure to
areas of lower pressure.
(Second Law of Thermodynamics)
©Heyoka Solutions, LLC 2012
• CFM – cubic feet per minute;
• FPM – feet per minute
• Static pressure – resistance to flow - measured in "WC (iwg) or Pa (Pascal);
• Sone – linear measurement of sound;
• HVI (Home Ventilating Institute) and HRAI (Heating Refrigeration and Air Conditioning Institute of Canada).
©Heyoka Solutions, LLC 2013
Whole Building Ventilation is dilution ventilation – “the solution to pollution is dilution”.
Courtesy of Panasonic
& Paddy Morrissey
©Heyoka Solutions, LLC 2012
(4) “Air” Changes = 6.25% Pollution
Pure “Pollution” (2) “Air” Changes 25% pollution
(1) “Air” Change
50% pollution
(3) “Air” Changes
12.5% pollution
©Heyoka Solutions, LLC 2013
1. Natural airflow through the building depends on many factors including temperatures, wind, mechanical forces, etc. It is not constant. It is variable.
2. People essentially need the same amount of fresh air to breathe. It is constant. It is not variable.
3. You cannot satisfy a constant need with a variable source unless that source constantly exceeds the need.
9
©Heyoka Solutions, LLC 2013
10
People
Building Air Leakage
Time
Wea
ther
Over ventilated
Under ventilated
©Heyoka Solutions, LLC 2012
©Heyoka Solutions, LLC 2013
National Ventilation Standard
Single family, multifamily up to three stories, and manufactured and modular buildings;
Considers chemical, physical, and biological contaminants but does not consider thermal comfort;
Acceptable IAQ will not necessarily be achieved even if all requirements are met.
©Heyoka Solutions, LLC 2013
Requires whole-building ventilation in all new and the majority of existing homes;
Provides sizing procedures;
Outlines equipment parameters;
Requires installed system testing.
Requires local exhaust ventilation in bathrooms and kitchens in all homes;
Provides sizing procedures;
Outlines equipment parameters;
Requires installed system testing.
©Heyoka Solutions, LLC 2013
Select a whole building airflow from the table (or calculate it);
Select appropriate airflow rates for local exhaust;
Select quiet equipment whose performance is certified by HVI;
Install it so it works; Test it to prove that it works; Document the design.
Edward Brannock, Pilot & Entrepreneur
©Heyoka Solutions, LLC 2012
©Heyoka Solutions, LLC 2013
Ventilation rate by the formula or by the table.
Pick a number from the table:
How big is the house?
How many bedrooms does it have?
©Heyoka Solutions, LLC 2013
Floor Area (ft2) 1 2 3 4 5
<500 ft2 30 38 45 53 60
501 – 1000 45 53 60 68 75
1001 - 1500 60 68 75 83 90
1501 - 2000 75 83 90 98 105
2001 - 2500 90 98 105 113 120
2501 - 3000 105 113 120 128 135
3001 - 3500 120 128 135 143 150
3501 - 4000 135 143 150 158 165
4001 - 4501 150 158 165 173 180
4501 - 5000 165 173 180 188 195
Example: 1200 square foot house with 2 bedrooms. Requires 68 cfm continuous ventilation.
©Heyoka Solutions, LLC 2013
Formula:
Qtot = 0.03Afloor + 7.5 x (Nbedrooms +1)
Example: Same 1200 square foot 2 bedroom house: (1200 x .03) + 7.5 x (2 + 1) = 36 + 22.5 = 58.5 cfm Lower airflow than the table, but remember that 62.2 is a MINIMUM ventilation guideline.
©Heyoka Solutions, LLC 2013
If the home has had a blower door test, the actual infiltration can be used to adjust the ventilation rate.
0.052 x CFM50 x S x wsf = “infiltration credit”
©Heyoka Solutions, LLC 2013
Atlantic City Intl AP 0.53
Belmar Asc 0.52
Caldwell/Essex Co. 0.44
Cape May Co 0.49
McGuire AFB 0.48
Millville Muni AP 0.44
Newark Intl AP 0.54
Teterboro AP 0.5
Trenton Mercer County AP 0.48
There are 1100 ‘wsf’ factors!
1 Story 1
1.5 Stories 1.18
2 Stories 1.32
2.5 Stories 1.44
3 Stories 1.55
Building height
factors (s)
Wsf factors for NJ:
©Heyoka Solutions, LLC 2013
1200 square foot, 2 bedroom, 1 story house in Trenton, NJ
Initial Blower Door number of 1400 CFM50
0.052 x CFM50 x S x wsf = “infiltration credit”
0.052 x 1400 x 1 x 0.48 = 34.9
©Heyoka Solutions, LLC 2013
1200 square foot, 2 bedroom, 1 story house in Trenton, NJ
Initial Blower Door number of 1400 CFM50
Original whole building ventilation rate = 58.5
With infiltration credit:
58.5 – 34.9 cfm = 24 cfm
©Heyoka Solutions, LLC 2013
1200 square foot, 2 bedroom, 1 story house in Trenton, NJ
Initial Blower Door number of 1400 CFM50
Final Blower Door number of 1100 CFM50
0.052 x CFM50 x S x wsf = “infiltration credit”
0.052 x 1100 x 1 x 0.48 = 27.5
©Heyoka Solutions, LLC 2013
1200 square foot, 2 bedroom, 1 story house in Trenton, NJ
Initial Blower Door number of 1400 CFM50
Final Blower Door number of 1100 CFM50
Original whole building ventilation rate = 34.5
With infiltration credit:
58.5 – 27.5 cfm = 31 cfm
©Heyoka Solutions, LLC 2013
Gives credit for existing fans and operable windows and infiltration.
©Heyoka Solutions, LLC 2013
Compliance options for existing buildings:
o Whole building ventilation rate is the sum of the whole building rate determined by table 4.1 plus any deficit for existing spot ventilation fans minus an infiltration credit.
Measure the airflow through existing fans and compare that to the local exhaust requirements;
An operable window reduces the deficit by 20 cfm.
©Heyoka Solutions, LLC 2012
1580 square foot, 3 bedroom, 1 story house in Madison, WI (wsf = 0.61)
Initial Blower Door number of 1400 CFM50
Kitchen has a window and a fan that moves 60 cfm
Bathroom has a window and a fan that moves 20 cfm Existing fans can be left in place
Whole building ventilation rate can be increased
©Heyoka Solutions, LLC 2012
Operable Window = 20 cfm Kitchen requires 100 cfm. It has a window and a 60 cfm fan: 100 – 60 – 20 = 20 cfm “deficit” Bathroom requires 50 cfm. It has a window and a 20 cfm fan: 50 – 20 – 20 = 10 cfm “deficit” Ventilation deficit = (20 + 10)/4 = 7.5 Original Whole Building Ventilation rate:
1580 x 0.03 + 7.5 x (3 + 1) = 77 cfm Adjusted Whole Building Ventilation rate = 77 + 7.5 = 85 cfm
©Heyoka Solutions, LLC 2012
Adjusted Whole Building Ventilation rate = 77 + 7.5 = 85 cfm With Infiltration Credit for original Blower door number (1400 CFM50) :
0.052 x 1400 x 1 x 0.61 = 44.4
77 + 7.5 - 44 = 41 cfm With tightened home Infiltration Credit:
0.052 x 1100 x 1 x 0.61 = 34.9
77 + 7.5 – 34.9 = 50 cfm
©Heyoka Solutions, LLC 2012
1580 square foot, 3 bedroom, 1 story house in Madison, WI
Start
Blower door 1400 CFM50
Tightened Blower door 1100 CFM50
Initial Flow Rate 77 cfm
With Appendix A only
85 cfm
With Infiltration Credit & Appendix A
41 cfm 50 cfm
©Heyoka Solutions, LLC 2012
• The existing building calculation can only be
used for existing homes.
• A really leaky existing house can have a required whole building mechanical ventilation rate of 0 cfm.
©Heyoka Solutions, LLC 2012
©Heyoka Solutions, LLC 2013
The intermittent operation option adds a bit of complexity.
Short durations (3 hours or less cycle time) are simple:
Run ½ the time double the required flow;
Run 1/3 the time triple the flow.
©Heyoka Solutions, LLC 2012
Pin Timer
Electronic Timer
Progammable Intermittent Timer
Fan & Light Switch
©Heyoka Solutions, LLC 2012
©Heyoka Solutions, LLC 2012
Select equipment with performance certified by AMCA or HVI;
Very quiet: 1 sone or less – quieter than a quiet refrigerator!
Exhaust or Supply only ventilation;
Mechanically balanced ventilation;
Mechanically balanced ventilation with heat or energy recovery.
©Heyoka Solutions, LLC 2012
© Raymer, Residential Ventilation Handbook
©Heyoka Solutions, LLC 2012
Desiccant wheel ERV 2nd Law of Thermodynamics – Heat moves to cold, wet moves to dry Heat Recovery Ventilator (HRV) transfers heat from the warm air stream to the cool air stream. Energy Recovery Ventilator (ERV) transfers heat and moisture from warm, moist air stream to the cooler, drier air stream.
©Heyoka Solutions, LLC 2012
If the house is tight, in a heating dominated climate, less moisture inside the house will be removed by an ERV because it will be transferred to the incoming air stream. HRV and ERV efficiency ratings are based on balanced operation. Their efficiencies will change if they are connected to air handlers and run in an unbalanced condition. They need to be installed where their filters and cores can be maintained. They do not supply EXTRA air to balance other devices.
©Heyoka Solutions, LLC 2012
Fresh air supply
with a motorized
damper
Fan cycler switch runs air handle at 20
minute intervals
Supply side of air handler
Kitchen Bedroom
Bath
Source: Paul Francisco
©Heyoka Solutions, LLC 2012
Outside air supplied to return side of the air handler
Aldes CAR
AirCycler Field Controls Damper
©Heyoka Solutions, LLC 2012
Local ventilation removes the pollutants at the source.
©Heyoka Solutions, LLC 2013
Intermittent Continuous
Kitchen 100 cfm Vented range hood required if
exhaust fan flow rate is less than 5 kitchen ACH
5 ACH
Bathroom 50 cfm 20 cfm
©Heyoka Solutions, LLC 2013
Typical ceiling insert
bath fans.
Certified by HVI or AMCA
for both airflow and sound.
©Heyoka Solutions, LLC 2013
Range hoods
Exterior mounted fan
©Heyoka Solutions, LLC 2013
Select a whole building airflow from the table (or calculate it);
Select appropriate airflow rates for local exhaust;
Select quiet equipment whose performance is certified by HVI;
©Heyoka Solutions, LLC 2012
©Heyoka Solutions, LLC 2012
Air is lazy;
Electrons are more forgiving;
Never use “duck” tape;
Always choose the shortest, straightest path to the outside;
System must be serviceable;
Never, never, never vent into the attic.
©Heyoka Solutions, LLC 2012
• In-line fans are designed to drag air
through ducts;
• Propeller or axial fans are not good for
ducts;
• Backdraft dampers can cut the airflow in
half.
© Raymer, Residential Ventilation Handbook
©Heyoka Solutions, LLC 2012
The effects of duct length on airflow performance in more detail.
Actual length is the actual, physical
length of the duct run (how far is it from
A to B);
Equivalent length is equivalent
resistance to the airflow generated by
the fittings;
Effective length is the sum of the Actual
and Equivalent lengths.
Actual length + Equivalent length = Effective length
© Raymer, Residential Ventilation Handbook
©Heyoka Solutions, LLC 2012
Description Equivalent Length
(Ft) for rigid
ducting
45° adjustable
elbow, 2-piece
5
90° adjustable
elbow, 4-piece
10
Wye, equal sizes 10
Tee, take-off 50
Tapered
increaser/reducer
4
Hard
increaser/reducer
8
© R
aym
er, Resid
ential V
entilatio
n H
and
bo
ok
©Heyoka Solutions, LLC 2012
Description Equivalent Length
(Ft)
Triangular wall cap for round duct
with backdraft damper & bird screen
28
Triangular wall cap for round duct
with bird screen, without backdraft
damper
14
Rounded wall cap for round duct
with backdraft damper & bird screen
14
Louvered wall cap 16
Low profile soffit vent with
backdraft damper and bird screen
33
Roof cap, low-profile for round duct
with backdraft damper & bird screen
60
Roof cap, ‘goose-neck’, for round
duct with backdraft damper & bird
screen
71
© R
aym
er, R
esid
enti
al V
enti
lati
on
Han
db
oo
k
©Heyoka Solutions, LLC 2012
Increasing the duct diameter from 4” to 6” will dramatically reduce the friction loss.
From Jennings, Environmental Engineering Analysis and Practice ,1970
7.5 Pa 62.5 Pa
©Heyoka Solutions, LLC 2012
Ducts need to be supported;
Choose the shortest path;
Ducts running through unheated
spaces must be insulated.
©Heyoka Solutions, LLC 2013
“In theory, everything works in practice. In practice, it’s different.”
Yogi Berra
©Heyoka Solutions, LLC 2012
Duct Blaster with DG700
Q200 Duc-Tester
with DM-2 gauge
©Heyoka Solutions, LLC 2013
Calibrated Duct Tester Fan Under Test
Point A
When the pressure at Point A = 0 pa, the flow through the Duct Tester fan = the flow through the fan under test.
©Heyoka Solutions, LLC 2013
©Heyoka Solutions, LLC 2012
1. Set the Device on the DG700 to EXH;
2. Set the Config to correspond to the opening on the Exhaust hood (A1, B2, C3);
3. “T” both channel inputs to the hose connected to the Exhaust hood;
4. If the pressure on Channel A exceeds 8 pa, open the Exhaust hood to the next notch;
5. Read the flow on Channel B.
If the flow exceeds 124 cfm, a different device must be used.
©Heyoka Solutions, LLC 2012
A Balometer will measure flows between 10 and 500
cfm.
Vane anemometer is less effected by ambient conditions like temperature, humidity and altitude. Accurate between 0 and 75 cfm.
©Heyoka Solutions, LLC 2012
Brand Model ID Required Airflow
Tot. Installed Airflow Normal Boost
Fanwho Quantum 3 36.5 42 76
Ventilation Product Information:
Brand Model ID Function (Multi-speed, intermittent, etc.)
Fanwho IAQ4040 Multi-function, variable flow
Control:
System Function & Operating Notes
HRV designed to exhaust air from the bathrooms and supply air to the bedrooms, low speed continuous operation, manual boost.
Req. Maintenance Clean filters monthly. Replace annually.
Clean the core annually.
©Heyoka Solutions, LLC 2012
Go to the Heyoka website. Search for:
ASHRAE6213WBCW Plug in coupon code ASHRAE13 to get the Excel spreadsheet for free until 9/30/13!
©Heyoka Solutions, LLC 2012
Thanks for listening
Paul Raymer
www.HeyokaSolutions.com
. . . and that’s the name of that tune!
Read the book. Don’t wait for the movie!