Building Ventilation Standards, procedures, troubleshooting articles list
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Index to articles discussing building ventilation diagnosis, improvement, repair, inspection, standards & specifications:
Building Ventilation Design, Inspection, Diagnosis, Cure - articles: How to Inspect, Diagnose, & Repair Ventilation & Fresh Air (or Stale Air) Problems in buildings.
These articles explain how to inspect, diagnose and repair ventilation problems in buildings.
We suggest building ventilation methods and we describe the pros and cons of different ventilation approaches used to assure good indoor air quality, low building energy usage, and minimal building moisture problems.
We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.
Building Ventilation Design, Inspection, Diagnosis, Cure: key articles
Information is provided about visual clues of building condition as well as direct inspection for the presence or absence of proper building ventilation systems, pathways, and moisture and air barriers to stop leaks where we do not want ventilation.
Our page top sketch explaining the wind-washing effect on attic insulation is provided courtesy of Carson Dunlop Associates.
At left we show an example of severe indoor condensation at a window.
In the articles listed here we explain how to identify and correct various building leaks, moisture, and venting
problems such as ice dams, blocked attic ventilation, excessive indoor humidity, how to prevent indoor mold, and how to respond to building floods and
similar emergencies.
Our photo (above-left) shows extreme condensation at a building basement window.
Moisture at this level risks severe mold growth which can be costly to clean up, and over a longer time this condition invites rot or insect attack on the building.
Below is our list of articles on the diagnosis and cure of building ventilation problems.
To find what you need quickly, if you don't want to scroll through this ventilation design, equipment, installation & troubleshooting ARTICLE INDEX you are welcome to use the page top or bottom SEARCH BOX to search InspectApedia for specific articles and information.
FLOOR TYPES & DEFECTS - inspection, diagnosis, repair, and installation tips for resilient flooring, vinyl and asphalt floor tiles, wood flooring, tile floors, carpeting in buildings
HEAT LOSS in BUILDINGS, how to determine and calculate heat loss from a building (or heat gain in a cooling climate), how to evaluate building insulation, & how to insulate buildings. What will it cost to heat the building, where are the problems
HUMIDITY LEVEL TARGET - how dry does the building interior need to be? How Low Should You Keep Indoor Humidity to Avoid a Mold Problem?
ROOF ICE DAM LEAKS - what are ice dams, what causes them, why do they cause building leaks & mold. How to inspect for evidence of leaks, identify causes, and correct bad attic ventilation, improper roof venting, and these causes of attic mold or roof structure damage
MOISTURE CONTROL in BUILDINGS - home page of our extensive list of articles on how to identify and fix sources of building water or moisture problems
MOISTURE PROBLEMS in BUILDINGS, CAUSES & CURES Understanding moisture problems can steer you free of trouble", Steve Bliss: Building it Right, Solar Age, March 1983 p. 37, 38. -- Adapted with permission, from original material to form this web page article.
ROT, TIMBER FRAME - how moisture, vapor barrier, & insulation may conspire to rot a building
SHEATHING, FOIL FACED - VENTS - do we need to vent building walls with siding installed over foam board insulating sheathing
SOFFIT VENTILATION - design guide for proper soffit ventilation at the building roof eaves
THERMAL TRACKING, GHOSTING STAINS how to recognize thermal tracking or thermal bridging & how to diagnose Stains on Ceilings & Walls, Building Air Leaks & Insulation Defects, as well as other indoor air quality or building concerns
VENTILATION, BALANCED HEAT COST SAVINGS - how to calculate heating cost savings from correcting the building air change rate and using balanced ventilation systems
VENTILATION in BUILDINGS - home page for our extensive list of articles on how to properly ventilate buildings
VENTILATION DESIGN PROBLEMS & SOLUTIONS - describes common design issues in making a successful building ventilation system, providing solutions for various building venting and moisture problems with supply air & return air problems & solutions, Building indoor air pressure drop during ventilation, Building indoor air ventilation system noise problems & solutions, and building Ventilation airflow controls
WATER ENTRY in BUILDINGS: what the basement waterproofing companies don't tell you? Water entry prevention and repair suggestions.
WIND WASHING INSULATION at EAVES - how wind and air movement in to a building at soffit vents can push back insulation and lead to heat loss in buildings, ice dams, and even leaks into building walls.
WINTERIZE A BUILDING - how to protect a building and its plumbing and mechanical systems from freeze damage, how to shut down a building to minimize damage; how to de-winterize a building.
ASHRAE resource on dew point and wall condensation - see the ASHRAE Fundamentals Handbook, available in many libraries.
2005 ASHRAE Handbook : Fundamentals, ( book for sale at Amazon) Inch-Pound Edition (2005 ASHRAE HANDBOOK : Fundamentals : I-P Edition) (Hardcover), Thomas H. Kuehn (Contributor), R. J. Couvillion (Contributor), John W. Coleman (Contributor), Narasipur Suryanarayana (Contributor), Zahid Ayub (Contributor), Robert Parsons (Author), ISBN-10: 1931862702 or ISBN-13: 978-1931862707
2004 ASHRAE Handbook : Heating, Ventilating, and Air-Conditioning, ( book for sale at Amazon) Systems and Equipment : Inch-Pound Edition (2004 ASHRAE Handbook : HVAC Systems and Equipment : I-P Edition) (Hardcover) by American Society of Heating, ISBN-10: 1931862478 or ISBN-13: 978-1931862479
2004 ASHRAE Handbook - HVAC Systems and Equipment The 2004 ASHRAE HandbookHVAC Systems and Equipment discusses various common systems and the equipment (components or assemblies) that comprise them, and describes features and differences. This information helps system designers and operators in selecting and using equipment.
Major sections include Air-Conditioning and Heating Systems (chapters on system analysis and selection, air distribution, in-room terminal systems, centralized and decentralized systems, heat pumps, panel heating and cooling, cogeneration and engine-driven systems, heat recovery, steam and hydronic systems, district systems, small forced-air systems, infrared radiant heating, and water heating);
Air-Handling Equipment (chapters on duct construction, air distribution, fans, coils, evaporative air-coolers, humidifiers, mechanical and desiccant dehumidification, air cleaners, industrial gas cleaning and air pollution control); Heating Equipment (chapters on automatic fuel-burning equipment, boilers, furnaces, in-space heaters, chimneys and flue vent systems, unit heaters, makeup air units, radiators, and solar equipment);
General Components (chapters on compressors, condensers, cooling towers, liquid coolers, liquid-chilling systems, centrifugal pumps, motors and drives, pipes and fittings, valves, heat exchangers, and energy recovery equipment); and Unitary Equipment (chapters on air conditioners and heat pumps, room air conditioners and packaged terminal equipment, and a new chapter on mechanical dehumidifiers and heat pipes).
1996 Ashrae Handbook Heating, Ventilating, and Air-Conditioning Systems and Equipment: Inch-Pound Edition (Hardcover for sale at Amazon), ISBN-10: 1883413346 or ISBN-13: 978-1883413347 , The 1996 HVAC Systems and Equipment Handbook is the result of ASHRAE's continuing effort to update, expand and reorganize the Handbook Series. Over a third of the book has been revised and augmented with new chapters on hydronic heating and cooling systems design; fans; unit ventilator; unit heaters; and makeup air units.
Extensive changes have been added to chapters on panel heating and cooling; cogeneration systems and engine and turbine drives; applied heat pump and heat recovery systems; humidifiers; desiccant dehumidification and pressure drying equipment, air-heating coils; chimney, gas vent, fireplace systems; cooling towers; centrifugal pumps; and air-to-air energy recovery. Separate I-P and SI editions."
Principles of Heating, Ventilating, And Air Conditioning, ( book for sale at Amazon), A textbook with Design Data Based on 2005 AShrae Handbook - Fundamentals (Hardcover), Harry J., Jr. Sauer (Author), Ronald H. Howell, ISBN-10: 1931862923 or ISBN-13: 978-1931862929
1993 ASHRAE Handbook Fundamentals, (Hardcover book for sale at Amazon), ISBN-10: 0910110964 or ISBN-13: 978-091011096
Best Practices Guide to Residential Construction, by Steven Bliss. John Wiley & Sons, 2006. ISBN-10: 0471648361, ISBN-13: 978-0471648369, Hardcover: 320 pages, available from Amazon.com and also Wiley.com. See our book review of this publication.
Offermann, Francis (Bud) J., P.E., C.I.H., ASHRAE & Mark Nicas, Ph.D., MPH, C.I.H., USE WITH ADEQUATE VENTILATION ? [PDF], ASHRAE Journal, May 2018, also available as a PDF here with permission of the authors. Abstract:
Consumer products such as paints, cleaning chemicals, and adhesives often contain toxic volatile chemicals. When these products are used indoors, these chemicals are released into the air resulting in inhalation exposures to applicators and other occupants.
The resulting indoor concentrations can result in exposures that cause acute adverse health effects, including death, and/or explosion risks.
Warning labels on these products and information in “safety data sheets” often simply caution to “use with adequate ventilation.”
Excerpt: Providing consumers with the required ventilation
rates and product quantity limitations for indoor applications
of paints, cleaning chemicals, and adhesives
should significantly reduce adverse health impacts associated
with the use of these products.
U.S. Department of Energy Resources on Building Ventilation
CONTROLLING MOISTURE in LOG HOMES [PDF] U.S. Department of Energy and the more general (but brief) DOE article series on moisture control:
GUIDE to HOME VENTILATION [PDF] (2010) U.S. Department of Energy, EERE Information Center 1-877-EERE-INFO (1-877-337-3463) www.energysavers.gov retrieved 2019/10/03 original source: https://www.energy.gov/sites/prod/files/guide_to_home_ventilation.pdf
HUMIDITY LEVEL TARGET What indoor humidity should we maintain in order to avoid a mold problem?
US EPA & NYSERDA HOMEOWNER'S GUIDE TO VENTILATION [PDF] U.S. DOE & New York State Energy Research and Development Authority, retrieved 2019/10/03 original source http://bcapcodes.org/wp-content/uploads/2015/12/homeowners-vent-guide.pdf Excerpt:
Ventilation supplies fresh air to your home and dilutes or removes
stale air. There are many ways this can happen. For example,
opening windows to air out your home can supply fresh outdoor
air that dilutes stale indoor air. Turning on the fan over the
kitchen range or in the bathroom removes odors and moisture.
Other common examples of home ventilation include chimneys,
which remove combustion gases, and clothes dryer fans, which
exhaust warm, moist air and chemicals from laundry soaps.
You may already know if you have a ventilation problem. Do you
notice the sour smell of garbage from a trash can; a musty, gymlike smell coming from the bedroom walls; or mold or mildew in
closets, or on ceilings or exterior walls? Is there condensation on
the inside of your windows? Are your eyes irritated when you’re
at home? These conditions may be signs of poor ventilation.
VAPOR BARRIERS OR VAPOR DIFFUSION RETARDERS [PDF] U.S. Department of Energy original source: how vapor barriers work, types of vapor diffusion barriers, installing vapor barriers
VENTILATION US DOE , U.S. DOE, describes the purpose of building ventilation and three basic ventilation strategies:
WEATHER RESISTIVE BARRIERS - HOUSEWRAP[PDF] U.S. Department of Energy original source: how to select and install housewrap and other types of weather resistive barriers, U.S. DOE
Reader Q&A - also see the FAQs series linked-to below
On 2019-10-11 by (mod) -
Patricia
Vent must be extended to the building exterior, it may not terminate in the Attic.
On 2019-10-11 by Patricia
This is not an individual home. It is a three-story building
This is a condo setting, therefore there is a crawl attic
Is it legal to vent a bathroom into an attic that is a common area ie: third floor condo
On 2019-08-24 by (mod) - whole house fan/venting
Mike:
Is your whole house fan installed in the top floor ceiling & thus will vent out of any roof vents available: both ridge and soffits?
Or is it a roof exhaust vent fan installed in the roof itself - in which case when it's on the fan will suck air in at ridge and soffits and wont' be so great at venting the house ?
On 2019-08-24 by mike maruska
whole house fan/venting Today, 10:04 AM New build for son . I plumber 50 yrs. Industrial. 785sq ft ranch on crawl. roof has 12 ft ridge vent. Spec says vented sofetts-looks like 112' linear .
Builder installed home depot cheap 200$ whole house fan (kid smokes.) Sounds like helicopter-wife left house when he turned on. "he can turn it on to let het out then shut down" builder says trying to sell install- I found a quiet cool fan for 450 dollars with no sound (43 dba) I want instead of his cheapo oversized 3000 plus cfm fan. Issue now is venting. I need 2.5 cfm per sq ft as per recommended 3.0 is better. 780 x 2.5= 1950 cfm ---so the quiet cool 2250 cfm is the plan if possible.
My ridge vent is 18sq nfa inches per foot or 216 sq inches (12 ft long). soffet vent is ventilated dont know wha he will use there but 125 linear ft.
will this whole house fan even work absent holes cut in roof for vents to accomadate the 2250 quiet fan altrnative to his loud oversized cheapo? thought i read 1/2 ridge vent 1/2 sofitt vent somewhere. advise best way to go. paid 950$ for cheapo installed and would like to save whole house fan since he smokes -if possible.
On 2019-05-28 by ruth dickey
we have 1904 sq. ft. crawl space, doublewide, , we have custom wood skirting, , we have the original vapor barrier on the ground over the clay dirt floor, the top overhead is all buttoned up nice, , however, we have added numerous passive vents, and we get a lot of rain and humidity, , , there are noi leaks, , and rain water doeds not get in, we have gutters with extenders, to trenches, away from foundation, plus a dith for raian water in the rear, extending around one side of property for , so it does not get under crawl, however, also our hvac does not work, we do not use heat or air, we have wood stove in winter, and fans in summer,
so that is not a factor in the moisture of the crawlspace, m,, this wood skirting does not breathe, and the 8x14 inch or so soffit vents, they give you are not really 1 sq. ft. of passive vent air, that's recommended for every 150 sq. ft.
so we are going to add more passive air vents, and if we have to, , we ll add a new 6 mil plastic floor vapor barrier over the old one, a job that I dread, because the skirting has to stay on the whole time, and , in spots, its less than 15 inches high, with the anchor straps there and everything, we cannot get into a dehumidifier, they are very expensive, and this ,
vapor barrier under there, has sharp rocks all over under it, , its like Vietnam under there, with full knee and arm pads, ect., , I believr its just not getting enough venting, mainly, down the wide middle part, , and the jerks whpo installed it, blocked off two of the rear vents, , too low to the ground, where the metal frame is blocking them, ,
plus the wood skirting does not breathe, we chodse wood over other types for , strength, weed eaters ect., and for the cold winter months, , please advise., , will we be better off with steel skirting, and if so even though we cannot afford that for quite a while, what about in the winter?, we have heatape for pipes, but, again these 8x14 or so soffit type vents they give you are only half of the recommended 1 ft to 150 ft of space, thank you for your answers.
On 2019-05-15 by (mod) -
You should indeed follow the advice of your inspector. Even a smsll change in conditions can produce fatal carbon monoxide.
On 2019-05-15 by ken
My merchantal vent system on my oil boiler looks to be to low. Although I had no problems with it for 20 years an inspector came in and said I need it a foot high off the ground. Right now it is only a few inches of the ground. Never had any carbin monixide problems. Can you help me ?
On 2019-01-06 by (mod) -
Jerry:
Thanks for asking about cold air falling into the bath from a ceiling exhaust vent: it's probably an event that irks lots of people, especially in winter.
Cold air will fall down out of a ceiling exhaust vent fan for at least the following reasons:
1. there is a source of air that can enter the fan and duct system, such as a wall terminating fan vent that is not closing
2. cold air is more-dense, or heavier, than warm air, so if there is enough cold air supply in the fan exhaust duct, once it's in the duct system it can fall "down" in some locations, overpowering the natural wish of warm air to rise and escape out of the same path.
3. Wind or outdoor air currents blowing air into the exhaust fan terminating opening can be a big contributor to cold air backflow through the exhaust fan opening.
Take a look at the bath exhaust vent fan articles in the series starting at
BATHROOM VENTILATION CODES SPECS - home - https://inspectapedia.com/ventilation/Bathroom_Ventilation.php
for details on proper exhaust vent fan ducting, location, etc.
On 2019-01-04 by Jerry
What would cause cold air to come out of fan vent in ceiling of bathroom? stays cold you can feel a draft also. Thanks,
On 2018-03-22 by (mod) -
I have not seen such a requirement but I will research your question further.
There is a basic assumption with exhaust vents that any adjacent vent is working correctly, that is, it closes when it's not active. That's to assure that there's not a backdraft from another nearby exhaust nor from any other source.
On 2018-03-22 by Geode
I would like to know if there is a code requirement for minimum distance between two bathroom exhausts through an exterior wall, each separate ducts and separate exhausts.
Both would run through attic space thru gable end. They would be well away from windows and no other exhaust or intakes located in same wall. I don't see an issue especially if both had baffles.
VENTILATION in BUILDINGS at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.
ASHRAE resource on dew point and wall condensation - see the ASHRAE Fundamentals Handbook, available in many libraries.
Best Practices Guide to Residential Construction, by Steven Bliss. John Wiley & Sons, 2006. ISBN-10: 0471648361, ISBN-13: 978-0471648369, Hardcover: 320 pages, available from Amazon.com and also Wiley.com. See our book review of this publication.
Offermann, Francis (Bud) J., P.E., C.I.H., ASHRAE & Mark Nicas, Ph.D., MPH, C.I.H., USE WITH ADEQUATE VENTILATION ? [PDF], ASHRAE Journal, May 2018, also available as a PDF here with permission of the authors.
CONTROLLING MOISTURE in LOG HOMES [PDF] U.S. Department of Energy and the more general (but brief) DOE article series on moisture control
Ventilation", U.S. DOE, describes the purpose of building ventilation and three basic ventilation strategies
...
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
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TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop Weldon & Associates Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
The HOME REFERENCE BOOK - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
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HOME INSPECTION EDUCATION: HOME STUDY COURSES - ASHI@Home Training 10-course program. Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
The Horizon Software System manages business operations,scheduling, & inspection report writing using Carson Dunlop's knowledge base & color images. The Horizon system runs on always-available cloud-based software for office computers, laptops, tablets, iPad, Android, & other smartphones
Building Ventilation
Information is provided about visual clues of building condition as well as direct inspection for the presence or absence of proper building ventilation systems, pathways, and moisture and air barriers to stop leaks where we do not want ventilation.
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: info@carsondunlop.com. The firm provides professional
HOME INSPECTION SERVICES and also extensive HOME INSPECTION EDUCATION and home inspection-related PUBLICATIONS. Alan Carson is a past president of ASHI, the American Society of Home Inspectors.
The HOME REFERENCE BOOK - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. 
