From the desk of George Kopf, Training & Employment Manager at Rising Sun Energy Center, Berkeley CA:

If you were relieved when BPI announced the delay of the implementation of ASHRAE 62.2.2010, you're not alone.  I am right there with you.  I don't know about you, but I struggled with 62.2.2010.  I like to think of myself as fairly intelligent and resourceful but, after hours of study and research, I am still unable to fully understand how 62.2.2010 works.  62.89 makes sense to me and I have used it accurately for years.  62.2.2010 is, IMHO, unnecessarily complex, confusing and difficult to use. 

Well, imagine my joy when I discovered ResVent's 62.2 app for my iPod!  For only $19.99, this handy little app will perform all the 62.2.2010 calculations for me.  All I have to do is input the data into the right boxes and off it goes to perform its magic.  Overall, I found the app user friendly but, sadly, I still have no better understanding of how 62.2.2010 works.  Call me old fashioned, but I like to understand what I am doing and why I am doing it.  You know, just in case the battery in my iPod fails.

When I remarked to a colleague about my joy of having resolved my 62.2.2010 woes, she was kind enough to point out to me that, lo and behold, one of the committee members responsible for crafting 62.2.2010 is also one of the folks who developed, and is now selling, the ResVent 62.2 app. 

The fact that someone on the committee responsible for crafting an overly complex standard is now directly profiting from helping me out of the jam they created seems a little odd to me.

I respect ASHRAE and all the hard work they do.  I recognize that I didn't have to spend $20 on the ResVent app.  I also believe in free enterprise.  But, to be perfectly honest, when I discovered someone on the 62.2.2010 committee got at least a portion of my $20, I felt a little disappointed.

But then again, I am a little old fashioned.

Is this just a case of buyer's remorse?  Regardless, I felt a compulsion to share this information.

Views: 2208

Reply to This

Replies to This Discussion

To clarify, it is 62.2's requirements for ventilation of existing homes that is too complicated, particularly determining the airtightness (cfm50 or ACH50) below which continuous whole-house (vs intermittent local) ventilation is required. As George said, BPI's previous guidelines, which were based on 62-1989, were easy to understand and implement, while 62.2-2010's guidelines are not.

Great point Judy.  And the fact that, even after reviewing the standard itself, this was not clear to me again tells me the standard is confusing.  Thanks again Judy!

OK!  In the 89 standard it was simple to get a number.  You ran a blower door. Looked at the map, picked an N factor for height and exposure.  Since I am near a border of two different zones, and no one has been able to tell me where the line falls, then *I guess*.  Then you apply some calculations.

Take the answer!  Below 0.35 MV is needed, above not needed.  Simple perhaps, with a huge guess on the n-factor, Yep! That is what we should be doing, making guesses, not applying standards.  Sorry guys, I disagree.

I use the app on my iPad and iPhone. I have also downloaded the spreadsheet from Paul Raymer's website at no charge. The web based app from Rick Karg is new to me, so I will have to look.

Tectite has a section to will calculate the 2010 numbers, Fantastic probably does; as does RemRate.

The 2010 standard is easy.  Instead of saying maybe you need MV or maybe you don't; it says everyone gets MV, the question is at what rate. 

So you start with your formula involving sq feet and bedrooms.  Then you allow for the effects of the spot ventilation and the shell leakage from your blower door test.  Those allowances reduce the amount of ventilation you need.  You may reduce from 80 CFM to 40 CFM  or to 0 CFM.  It is just a reduction.

Use Paul's spreadsheet to understand how the calculations work. I did. Quit guessing at a number, quit leaving homes without air sealing because it might go below the guess at what 0.35 might be.  If you blow your guess, you screwed up.

Programs that don't want to chance sealing below .35 are operating with a 40 year old mentality. They are more into saving money instead of actually providing value.

Thanks for the kind words, John.  George, I put together a comprehensive on-line course on 62.2-2010 for Energy Logic that you can get to through:

Kind of a long address, but you can try going to the Energy Logic Academy as well.

And Judy, I have to disagree with you about the complexity of the existing home calc.  First of all you don't even have to do it if you don't want to.  But if you want to leave existing fans in place, you have to measure the flow, and then go through a couple of basic steps to increase the whole building ventilation rate if the existing fans can't get it done.  I have been working with a number of weatherization agencies across the country, and the complexity is not in the calculations but in adding something else to a very small budget.

I would agree that using the infiltration credit with the blower door stuff got overly complicated, but we have wrestled that beast into line too.  And once again, you don't even have to use it unless you are so inclined.

But I think the problem lies in the direction we come at the problem.  We need to say, "We're tightening up your house and putting in a new ventilation system to improve the energy efficiency of your house for your health and safety."  The expected market for the air freshener industry is expected to hit $8.4 billion next year!  What are we covering up?

Paul you are completely right. The main complexity of the ASHRAE 62.2 standards is at the WAP level. There are some who argue that we are spending too much money in health and safety and we can no longer get positive SIRs for energy efficiency. Others argue that we need bigger budgets. There is also the question about low income home owners being able to repair or replace the fan when it fails. But few complain that its too hard to understand.

Are some of the posts on this thread stating that there are building performance professionals who hesitate to ensure safe IAQ levels because its too hard to figure out the standard? I hope not. I think we all know the standard is not intended to make the energy auditor's life any easier- its intended to ensure better IAQ for the residents.

Maybe its easier to simply accept the fact that as we improve systems for liquid water control, vapor control, air control and thermal control we must also improve ventilation controls. Some say we must treat the house as a system or take the whole house approach. No matter how we frame it, the bottom line for building performance is control. Tight houses that depend on wind pressures and delta T do not provide control.

We work in both new and existing houses MD where the 2012 IECC is in effect, and if the local jurisdiction has adopted the 2012 IRC, then 62.2-2010 is in effect.  Either use the simple formula or the table and put in the right fans regardless of blower door readings (the code mandates less than 3 ACH50) - very easy.

BUT - if that new house gets a BPI audit a month after occupancy, we now have to measure the output of the fans and use the actual output, then calculate other factors from the blower door number in the much more complicated fashion, and then almost always have to install a larger fan.  We have already seen this with a 6 month old house under the 2009 IECC in another state.

So same standard, different results for new and existing homes.

Also, we have to solve the problem of tightening the house to 69% of BAS, and then having to re-ventilate to 100% BAS rather than 70%. 

Ed Minch


I'll sell you my ASHRAE 62.2 2010 excel spreadsheet for $20!

I think 62.2 is fairly easy.

What we have to remember that it's a minimum standard, based on an assumed "natural ventilation" (leakage rate) of 0.15 achnat.

I have never subscribed to 0.35 achnat being a maximum air leakage rate, and that if you are above it that you don't need mechanical ventilation.

All houses need mechanical ventilation, and most are too tight.

We should be applying 62.2 on all houses (new & existing).

If you are not recommending mechanical ventilation on homes without it, but you are air sealing & insulating, you are committing malpractice! And sadly my experience includes "building performance contractors" doing just this.

What's the difference between a "new home" and an "existing home"? A new home nobody has lived in, and an existing home has been lived in. Yet we treat them differently? Why?

What I am concerned about is that many projects are tight enough that we don't want to have exhaust only ventilation, we need balanced, or need makeup air.

I thought somewhere I saw mention that the 62.2 2010 standard was available for free from ASHRAE, but don't seem to be able to find it. I can find some supplements for free, but they are incomplete.

Can anyone point me to a free or cheap version (not the $55 book).

I know there are a lot of words in the standard, but most is reasoning or justification. Check Iain Walker's reply, this stuff is easy.

By the way, I don't know Rick Karg well but every time I have every time met him he has been generous with his time and knowledge. He has been working and training in this field for years and is very well respected. Complaining about how he makes his living is uncalled for. Most "high volume" apps are lower priced but specialized apps for small markets are commonly costlier.

I would have buyers remorse for paying the $20 especially knowing there are software available that will calculate the ASHRAE 62.2 data for you, allow you to complete audit, run the energy model, and print a  homeowner report (customized by you) all in the field without requiring an internet connection.  Full disclosure, I work for a software company that provides just that. 

If you look up posts from me on this site from September to November you will find a few that were bitching about 62.2-2010.  I am gullible enough to believe that when BPI says they are going to do something they will do it, and I am old school enough to hate change. 

But I am proactive enough to prepare for change. BPI started suggesting 62.2-2010 last summer.  A local WAP agancy offered training last October.  I spent $800 and sent 4 guys to that training so they could be ready for 62.2-2010 in Jan 2013.  Luckily at that training we got a spreadsheet template. 

I started using that template immediately on jobs we were bidding.  So far only one house I looked at needed venting.  That house was so tight the owner called us asking for an energy audit knowing he did not need any energy upgrades, he just needed a fan, but more than that he needed to know how big the fan had to be.  The spreadsheet handled that beautifully and we put in a HRV for that guy sized by the spreadsheet.  It is working as the sheet predicted. 

Every other job I took the spreadsheet, entered and bathroom or kitchen windows seen.  ignored fans, and used the BAS 62.2-89 computed as the expected test out blower door reading.  When I do that, we never seem to need an additional fan.  I have not yet had a case where predicting the result this way lead us wrong.  I suppose some day I may find  client with a house where we will get the house below BAS and my workaround will be wrong.  I hope that I can predict that by knowing the job before we begin.  That model will not work for commission based sales guys who don't really know what they are selling.  It will work for craftsmen who sell what they know. 

Then BPI cancelled imposing 62.2-2010.  Personally I am out $800, not $20 so I feel more irritated that the standard is not being used now. 

I cannot understand why anyone is upset about paying $20 for an ap.  When you look at the standard and think about it, then find out there is an Ap out there, the decision is "Is it worth more than $20 to me to figure out how to manipulate the standard into my own spreadsheet, or should I just pay up?"


Wonderful input here from everyone. Iain, Paul, Rick, I know you've worked long and hard on 62.2, but it does need some tweaking as do all the various programs trying to implement it smoothly.

I'm a fan of ventilation, but I also need to vent. <rant on> While convincing clients that air-sealing and adding mechanical ventilation (MV) is a good idea ("Do you want to be in charge of your house "breathing", or do you want Mother Nature to be in charge?"), I have some issues with implementing the standard(s) the way it is written.  

Using the Ventilation Air Requirements table adds more ventilation than using the calculation, but the Infiltration Credit was removed with Addendum n. Oh wait, it's coming back in for -2013.  Maybe.  But then there's the Total Ventilation Rate Method.

We want that infiltration credit in whatever form we can get it.  Some homes won't need MV if we take into account infiltration.  Don't get me wrong, I think every home should have MV, but there is inadequate funding for doing that.

So if we just use the Total Ventilation Rate Method and calculate the envelope leakage using ASTM E779 or CGSB 149.10, we can allow for the Effective Annual Average Infiltration Rate.  Now just hold on a minute.  I've got a blower door and a front coming in, and I'm trying to do weatherization triage on this shack. Why can't I just use

ELA = (CFM@50 x .055)/144

to get from CFM50 to ELA to NL to Qinf ?  It's triage, not a research project.

Ventilation standards implementation has a created an implementation nightmare in NY for program managers, trainers, auditors and contractors.  In NY State, a contractor will need to know 62-89 (per NYS code and BPI), 62.2-2010 (per WAPTAC and BPI), and 62.2-2010(n) (per NYSHCR and WPN 11-6) depending on which job he is working on.  Otherwise, contractors will need a master spreadsheet which calculates all three methods and provides the minimum ventilation rate that satisfies all the standards.  I'm building that spreadsheet. Donations accepted.

An underfunded mandate to apply a standard to non-standard housing stock runs amok with WPN 11-6, SIR calculations, H&S budgets, and energy savings. With funding dropping off even further, I would expect more units will be deferred rather than weatherized.

The solution is more funding for H&S (for more than just ventilation), easy infiltration allowance, and auditor empowerment to deal with the bizarre situations.  

Oh yes, and what about RIVEC-based ventilation control? (And I had my Arduino controller half built).  If we're about saving energy while ensuring good IAQ, we need mechanical ventilation rates that varies with delta-T, humidity, wind, and occupancy numbers. CO2 and VOC monitoring would be nice, too.  I don't expect to see that in the standard before 62.2-2016, unless an addendum comes out allowing it.  <rant off>

Okay, if I ruffled any feathers, I'm sorry.  If I've got facts wrong, please correct me. I'm confident that when the dust settles, we'll have raised the quality of life for home dwellers another notch, while saving a little more energy.


Latest Activity

Summer Reyes posted a blog post
21 minutes ago
Oliver Periman is now a member of Home Energy Pros Forum
8 hours ago
Bob Krell joined Tom White's group

Trainers and Mentors

Share your experience with different training and mentoring methods. Learn about new training…See More
Bob Krell replied to Bob Krell's discussion What Do You Do When You Find Suspected Mold? in the group Healthy Indoors (IAQ)
"Most of the moisture issues there can be attributed to failure to get the roof system completely…"
Bob Krell replied to Bob Krell's discussion What Do You Do When You Find Suspected Mold? in the group Healthy Indoors (IAQ)
"You are correct about it being multi-family.  It is, in fact, an assisted-living facility, so…"
Quinn Korzeniecki added a discussion to the group Building Performance Institute (BPI)

Weatherization Pros: Only 9 Days Left to Apply for Free BPI Certification Exams!

Are you a weatherization professional? Don't miss your chance to get the costs of your new 2018 BPI…See More
Quinn Korzeniecki posted a discussion

Weatherization Pros: Get BPI Certification Exam Costs Covered!

Are you a weatherization professional? Don't miss your chance to get the costs of your new 2018 BPI…See More
Diane Chojnowski replied to David Butler's discussion Beginners Guide: Managing Subscriptions on Home Energy Pros
"Great guide David! Thanks! We send two weekly emails to keep members in the loop about new blogs,…"


  • Add Photos
  • View All

© 2017   Created by Home Performance Coalition (HPC)   Powered by

Badges  |  Report an Issue  |  Terms of Service