I have received an email about how BPI is to adopt ASHRAE Standard 62.2-2010, replacing 62-89. Just wondering if anyone can explain what the difference between the two standards is and how it affects energy auditors who are currently using 62-89?
Sure 89 is toast & 62.2's formula is (Total square foot of a home/100) + (Number of bedrooms + 1) x 7.5 cfm)
Now if you want to delve into a ton of the arguments about it - Carl Seville posted an interesting email thread about it as it relates to WX work
Sorry I have got to say it - you (generically stated) all are great at parroting the mantra "THE HOUSE IS A SYSTEM" & then you promptly forget all about it when you do your SIRS & payback equations. Christ I saw someone say they couldn't fix an issue once that would have only cost $10 because they couldn't figure out the payback on that item...
I like Rick's thoughts in the link above on thinking of the two tasks as.. ONE measure? What if we call this measure “taking control of airflow” or “controlling airflow”? The first task of this “controlling airflow” measure is air sealing. Air sealing reduces uncontrolled air leakage. The second task of the “controlling airflow” measure is installing ventilation according to ASHRAE 62.2-2010 to ensure a controlled amount of fresh air. These two tasks go hand-in-hand as the two parts of controlling airflow; one is not appropriate without the other; they are synergistic. In this conceptual frame, air sealing and ventilation are no longer battling one another as two distinct, conceptually opposed measures.
There's a fairly cheap "Exhaust Fan Flow Meter" from Energy Conservatory that's worth owning, and if you don't want to buy theirs I've seen instructions for a home-made version. I have the TEC product, use it, and like it.
Pat, you will almost never need a 100 cfm continuous fan to meet 62.2, unless the home is very large (>3,500 ft2). Whole house mechanical ventilation rates are on the order of 0.17 ACH, which is usually in the 35-60 cfm range. Much smaller fan than what you are talking about. Almost any fan you install that meets either the bathroom (50 cfm) or kitchen (100 cfm) requirements will be more than big enough to satisfy whole house requirement.
You are certainly right that ventilation is not a net-energy saving measure, it is an energy consuming measure; unless significant air tightening also occurs, then you may still get net-savings. It will only have an SIR if we incorporate health care costs.
You are absolutely right that regulation and government are the answer. We need proper practice to be incorporated into law, like Title 24 in California, which requires energy modeling, 62.2 compliance, etc. The home performance contractor will have a very hard time making a profit without structural measures that push homeowners to hire them.
The Exhaust Fan Flow meter is a cheap tool, ~125. An even cheaper method is a garbage bag and a stop watch. You know the volume of the garbage bag, apply it to the register to and time its filling/emptying. This is much easier to do with supply airflows, but can be done from exterior for exhaust airflows. http://www.cmhc-schl.gc.ca/en/co/maho/yohoyohe/inaiqu/inaiqu_003.cfm
This is a surprisingly accurate and repeatable test.
most fans are rated without ducting attached. a duct and a couple elbows will rapidly reduce a 100 cfm fan to 50 cfm. at full speed. that is why i said 100+ cfm fan.
There is a great deal of furor about the ASHRAE 62.2-2010 Standard a lot of which comes from only looking at parts of the Standard. Like a house, the Standard is a system and should be taken as a whole. Having said that, I want to look at a couple of parts. The Standard was originally crafted for new homes, but has been modified to make allowances for existing homes with existing fans.
It does require whole building and local exhaust ventilation. The simplest way to get the whole building ventilation rate is to use the floor area and the number of bedrooms (plus one) and use the table. You will get a slightly lower ventilation rate by using the formula, (.01 times the floor area plus 7.5 times the number of bedrooms plus one). For an existing house, you can adjust that rate even further by applying the “infiltration credit”. For a very leaky house, the rate can actually be reduced to zero! But, of course, you don’t want a very leaky house! The process of applying the “infiltration credit” can be bewildering, but there are some great Apps and spreadsheets available that make it simple. (There is a free one on my website at www.HeyokaSolutions.com).
The standard does also require local exhaust ventilation, removing the worst pollutants at their sources in kitchens and bathrooms. While the sound level for the whole building ventilation system has to be quiet (less than 1 sone) or people will definitely shut it off, the sound level for the local exhaust ventilation for newly installed fans can be as loud as 3 sones.
If there are already existing fans in the bathrooms or kitchens, Appendix A of the Standard allows you to leave those in place no matter how little air they move or how noisy they are. You may need to adjust the whole building ventilation rate to compensate for a weak bathroom fan or range hood. For example, a kitchen with an operable window (20 cfm “value”) and a 70 cfm fan would reduce the required 100 cfm to 10 cfm (100 minus 20 plus 70). A bathroom with an operable window (20 cfm “value”) and a 30 cfm fan would reduce the 50 cfm requirement to 0. You add up all the deficits (in this case 10 plus 0) and divide by four (2.5 cfm) and add that to your whole building requirement. So you can leave the existing fans in place (vented to the outside) or you can replace that bathroom fan with a quiet, efficient fan that meets the whole building requirement and the local exhaust and let it run all the time. There are excellent fans that will meet these requirements for under $130.
You don’t need to add a control per the Standard. You just need to be sure that the switch that controls the whole building ventilation system is marked to indicate that is what it is for. Some manufacturers will supply that labeling with their fans. Of course, if people shut it off the whole ventilation effectiveness goes away (can’t say out the window) so you could put the switch in a less obvious spot. It just needs to be accessible by the homeowner. If you want to run the fan intermittently, then you have to buy a more powerful fan as well as the control. So keep it simple and run it continuously. The electrical energy used is tiny. The fan mentioned above uses about the same power as the transformer for your doorbell. There is a conditioned air cost, but that is also small, roughly about $0.25 per day depending on a whole bunch of stuff. You get the savings from being able to tighten up the house without impacting the health of the building or the occupants.
The required testing can be done with the TEC flow hood ($135) or a garbage bag taped to a hanger (go to the CMHC website for how to do that) or with your duct tester or your blower door if you want to test a range hood!
I totally agree with you, Pat, that we’re still in the trend setter part of the market, but it’s a lot better than it was when I started doing energy audits in 1978. The fact that ASHRAE 62.2-2010 is now a requirement means that ventilation is being pushed to the forefront. We need to keep educating homeowners and builders and HVAC contractors that it is important and it doesn’t have to be that hard or expensive.
Thank you for this Paul. I was on a webinar yesterday where either I heard the methodology for existing fans wrong, or it was presented wrong.
Am I to understand from this that if an existing fan does not vent to outside, you must make it vent to outside?
Does it mater if that fan is burried and inacessible (cathderal ceiling, or lower level ceiling)?
The fans themselves can be purchased for 120-130, yes, plus tax, plus handling charges, plus freight, plus controls, plus electrician in some jurisdictions, plus labor to install, plus risk (there is always risk) plus accessory items like duct and exterior hoods, plus working in the attic and/or on the third story gable end, etc., oh yeah, plus profit.
i ordered your calculator and will have a look at it tomorrow.
I think BPI should stop raising the bar and bashing me in the head with it, and start going on TV to establish themselves, and us, as consumer advocates. it is time for them to start moving the mountain and stop persecuting their followers.
BPI shoudl be mentioned every time Holmes on Homes goes on TV. Consumers should be asking for BPI folks. Holmes could help establish BPI as a consumer advocate, and BPI needs to explore that. 10 years in, they still are not known by the general public in NY.
Hang in there, Pat. Geez. So much frustration! If there is an existing fan venting into the structure of a cathedral ceiling or into the ceiling or into the attic, you know it is doing damage! I worked on a house in NJ where the wonderful old lady who lived there had about a dozen bath fans installed in her ceiling venting into the attic because her late husband had a thing for bath fans. Rather than remove them which would have impacted her memories, we unplugged the fans so they wouldn't run, and sealed them up from the attic.
The advantage there, of course, was that we could get to them from the attic. If they can be vented outdoors, they have to be vented outdoors. If they can't be vented outdoors . . . they should be decommissioned so they won't do any more harm. (That's not in 62.2. It's just practical stuff.)
Here's another thing. There are a handful of us on the 62.2 committee who are really concerned about how the Standard impacts existing buildings. If there are things in the Standard that we are missing, I would truly appreciate taking that information to the meetings and seeing what we can battle through to get it fixed. The Appendix A stuff got done in the shortest time I have ever experienced, mostly in one evening (with beer) in a hotel room! I have written the section of the new BPI Standard relative to IAQ and Ventilation. I think it's pretty good, but we'll see.
thanks again. get it in the standard to 'decommission' fans that cannot be corrected if you can please. inspectors tend to look at the world as black & white and refuse to consider greys.
also please get BPI to do some advertising directed at consumers. Good Housekeeping, Better Homes & Gardens, Holmes on Homes, This Old House, etc. that is how companies like Icynene became marketing marvels.
I agree, would love to see some marketing for the Home Performance Industry...
Mike Homes is a great place to start. But I'm a fan of doing things myself and not counting on others. I'd like to see the contractors of NYS come together and promote the HP ourselves.
The old standard sounded good but really was not based on any real data or science pertaining to small homes that I know of.
So now we should just vent out the savings.
Sure, If we tighten a house up we just might cause some type of health problem. After all, the house is a system. Right? So why not just open the window because I wonder where the FRESH air we bring in is coming from or has been. Guess that's not important, lets charge a homeowner money to tighten up the house to save money and improve their comfort. Then charge money to install mechanical ventilation to suck out the savings. God forbid we stop importing nasty’s from China. Or ask corporate America’s to stop selling poisons as cleaning products. Shouldn’t the EPA or DOE require ovens to be vented outside. Why, it is easier to make hard working contractors to force it on working poor Americans then have corporations take responsibility….
It’s a WIN, WIN, WIN all around, unless you’re a working man trying to meet a SIR….
The big problem I have with this is a one size fits all approach.
No one other then the auditor, who has eyed the job site and interviewed the homeowners, should be making the recommendations. In our business there are just too many variables. Smokers, pets, extremely dirty homes or over cleaned. Hobby shops, home business, nail and hair salons. I’m not saying standards should not be used as guides but not written in stone. Really how is anyone able to say what is needed or not unless you have surveyed the site?
There is no other industry that does sch good and is required to know so much on so many levels than ours. Doctors, Lawyers, Police? Our jobs are hard enough, without being Q/A and scrutinized to death then guided from afar.