Amazing Email String about Weatherization and ASHRAE 62.2
By Green Building Curmudgeon|Published: June 8th, 2012
At ACI this year, I had the pleasure of meeting many members of a group known as the Trainers Consortium. Following a recent conference call, which I was unable to attend, the following email string appeared in my inbox. Barely able to keep up with the conversation, I felt that it deserved broader distribution as it covered some very important and interesting (at least to us geeks) topics. Please enjoy the conversation an add your own thoughts:
And so it begins:
During the Trainers Consortium conference call yesterday about ASHRAE 62.2, I had a thought that might help some of us with a big conceptual problem.
First, the problem: I have always thought of air sealing as a distinct weatherization measure. And I have always thought of installing ventilation as a distinct weatherization measure. Air sealing saves energy and increases thermal comfort. Installing ventilation is a health and safety activity that does not save energy, but increases energy use. For the last decade or more I have been frustrated by my inability to convince people that it is a good idea to air seal a house and then install ventilation. For many people, it seems that these two measures are working against one another, or that one undermines the other. Of course, as trainers, staff of the DOE low-income weatherization program, private contractors, or members of the ASHRAE 62.2 committee, we want to find a way around this conceptual problem.
The solution? What if, rather than thinking about air sealing and adding ventilation as two distinct measures, we think of them as two tasks of 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.
I think this conceptual frame might help us foster “buy in” from installers and home owners, which, by the way, was the primary topic of the conference call yesterday.
Taking this idea a bit further, perhaps we should not look at the benefits of air sealing alone, but look at the benefit of controlling airflow. The benefits of controlling airflow are 1) reduced energy loss from air leakage, 2) increased thermal comfort, 3) enhanced health, and 4) lower medical bills. The costs of controlling airflow are 1) labor and materials for air sealing and 2) cost of installing ventilation fans and controls. The Wisconsin low-income weatherization program has found that there is a significant net dollar benefit when air sealing savings and ventilation costs are bundled together. The SIR of “controlling airflow” can be calculated in this manner.
Congratulations, Rick! Love it! I think you’ve finally tied a hair ribbon on the bolt of lightning, to paraphrase WC Fields. Have to give some credit to Tony Gill for inserting the control concept as well. Who says Mainiacs don’t know what they’re doing?
And we need to install balanced systems or sealed combustion appliances, because the atmospheric water heater is part of the synergistic system and if we tighten the home and only install a continuations exhausting fan we will back draft the water heater and ruin indoor air quality, not to mention if we create a continious negative pull on the house we will increases any radon problem, again ruining the indoor air quality, adding to medical and burial costs not to mention liability. If we install fans that pressurize the home we will shorten the life of the building by driving moisture into it's structures.
I say install HRVs or ERVs to reduce the energy penalty. You still get to sell fans and software and it takes care of all the problems.
I wasn’t present for the call, but I hope you’ll allow me to ask a few questions.
The frustrations related to ASHRAE 62.2 are more complex than trainers just failing to understand the ideals that Rick so skillfully expresses. WAP State programs, local agencies, and private contractors tried to achieve a balance between air sealing and ventilation for decades before 62.2.
Some trainers wonder whether the advocates of ASHRAE 62.2 have proof that this new standard really delivers: “1) reduced energy loss from air leakage, 2) increased thermal comfort, 3) enhanced health, and 4) lower medical bills” compared to the previous approach.
Other questions include.
1. Did ASHRAE consider the depressurization issues (backdrafting, radon, soil gases) that could be caused by the retrofit fans?
2. Did ASHRAE consider the need to clean fan blades, grills, and filters to maintain the airflow of the newly weatherized homes with their increased airtightness?
3. Could ASHRAE communicate its standards in plain English without confusing omissions like the exception to fan installation for leaky homes, which is implicit (unstated) rather that explicit (stated) in the standard?
4. Is the large commitment of training costs and WAP direct expenditures justified by ASHRAE 62.2’s benefits?
We may have to wait a while for the answers to these questions.
I absolutely agree with Joe, although think there may be several alternatives to power venting every DHWT.
The pragmatic application of Rick's stated concept is combining testing for combustion safety, ASHRAE 62.2 and infiltration into a single steps of service and using a single diagnostic tool to diagnose any critical measures.
In IL we are beginning to use a spreadsheet which I believe was designed by Paul Knight and Paul Francisco. I am fairly certain it employs a formula that only suggests ventilation needs and defines depressurization limits for that building.
After performing a systematic test of a building a customized set of measures can be made based on the results of the diagnostic tool. That approach may not require any ventilation or inexpensive duct sealing or a power vented DHWT.
However, no matter what ASHRAE 62.2 or combustion safety measures are required, they should be braided into the air sealing SIR since you can't have one without the other.
Rick is right. The marriage of these ideas should be present in training, agency process and marketing materials.
Karg started it!
I’ll take John’s questions in order, and in that process I am also going to address Joe’s e-mail.
Proof of the 4 things Rick mentioned?
1) Reduced energy from air leakage – Rick didn’t actually say that was a direct benefit of 62.2, he said it was a benefit of controlling airflow. There is no doubt that by installing a fan to 62.2 we will be reducing our savings relative to air sealing to the exact same level and not installing a fan. However, to the extent that 62.2 promotes greater air sealing because we are no longer trying to “stop in time” to avoid the (BTL/MVR/insert obsolete acronym here) we do get reduced energy from air leakage. And certainly the NET benefit of the entire package can be a strong savings.
2) Increased thermal comfort – whenever you want to control the comfort in your environment you can do that better when you have air sealed. In museums, where controlled environments are rule #1, air sealing is also rule #1 (think about the cases they put displays in). As with #1, if 62.2 allows more air sealing to be done because we are no longer trying to avoid triggering (insert obsolete acronym) then we are better able to control our environment. The air sealing reduces the entry of outdoor air at different temperatures as well as different humidity. The fan reduces the amount of indoor-generated humidity as well as other contaminants. Wisconsin has done 3 studies that have showed lower CO2 and humidity in homes with 62.2. So I say the answer to this one is yes.
3) (and 4) enhanced health and lower medical bills – when we reduce the indoor contaminant levels (as shown in the Wisconsin study) there is every reason to believe that health improves. It may not be addressing an acute hazard but rather a long-term low-level issue. However, the quantitative studies have not yet been completed to put a value on that.
John’s other questions:
1) A – combustion safety: Yes, though not clearly well for retrofit homes. We discussed this on the call. 62.2 has a requirement for maximum total exhaust of the largest two exhausts, which is based on a 5 ACH50 home. This is a lot tighter than we often get our homes to. I am working to get that changed and made something more obviously friendly to WAP. For now my recommendation is that we use good combustion safety testing. I disagree with the notion that we should always install balanced ventilation. In many homes there is simply not a combustion safety problem, and it is a lot cheaper to determine that with testing than the incremental cost to go from exhaust to balanced ventilation. We should never say that one solution is always the solution. We should look at the house (all of them are different) and figure out what makes the most sense.
B – soil gases and radon: No, but I disagree with the automatic conclusion that 62.2 makes the situation worse. The fan does change the pressure in the home by some amount, often small, which can bring in more soil gas. It also dilutes the air in the house – that is the purpose of ventilation – which will get rid of more soil gas. While the data are not yet available, my estimates suggest that we will dilute more than we will bring in, and 62.2 will be a net benefit when it comes to soil gas.
2) There are no specific requirements for maintenance. 62.2 is not in a position (any more than NFPA is in a position on furnaces) to mandate maintenance by users. People often use this maintenance issue as an argument against 62.2. In some ways the fan is different than a furnace, because people will figure out a way to replace a failed furnace (or just turn on the gas oven and open the door) and they might not for a fan. But when we install a new furnace and that has a filter we do not have any way of knowing whether people will ever change the filter, but we install it anyway. And what about the condensate for a 90+ furnace? If the line gets clogged or the pump fails, I am not at all confident that the owner will get it fixed. But we install 90+ anyway. I will say that good exhaust fans look to me to be a lot more robust than a furnace fan. Take a good exhaust fan and put a piece of paper over 75% of it. You will lose some flow, about a quarter. Now choke off 75% of the return inlet to the furnace. You will likely lose more than 25%, and you are more likely to cause high-temperature rise problems for the furnace. Good exhaust fans have been running for well over 15 years with little or no maintenance. I see the maintenance issue as a red herring.
3) Yes and no. We are required by ASHRAE to put it in code-intended language. Code-intended language is not plain English. However, in cases like the one John mentions, when it is brought to our attention we can fix it. We have membership on this committee so we don’t have to sit idly by and feel frustrated about confusion of these requirements. The example that John mentions, in fact, was rectified quite some time ago shortly after the confusion was brought to our attention. This example is now explicit.
4) This is a bit subjective. Some think yes, some think no. If we were able to quantify and monetize the non-energy benefits I think we would be much more all on the same page.
Finally, one thing that I am often confused about is whether critics of 62.2 are against any ventilation standard being used at all or whether it is a question of benefit relative to 62-1989. If the latter, look at it this way. The organization that made 62-1989 determined that it was inadequate for residential buildings. It would have been a lot easier to leave it alone, but they determined that it was a big enough problem that it needed to be addressed. Now, if an auto manufacturer says that one of their vehicles is defective they recall it, and we as consumers don’t buy any more of those until they fix it. ASHRAE recalled 62-1989. We should not be using it. So then the question becomes do we ignore ventilation altogether or not. If the answer is no, we don’t ignore it, then what do we use as guidance?
Hello all, My concerns up here in upstate NY with 62.2 are fairly simple. How do we keep our clients from turning off the ventilation units when it’s real cold? It’s counterintuitive to our clients to have a fan running when it’s 30 below in Saranac Lake. How do we address wood burning stoves in light of 62.2? With the cutbacks in HEAP I expect we will see more clients burning more wood in more cheap stoves. I’m hearing more reports of auditors performing audits on homes with no heat because the client has exhausted their HEAP benefits, how do we justify the additional expense of 62.2 in light of these funding cutbacks? Last but not least what happens when the ventilation system fails?
So far I’m not convinced of the rational for the implementation of 62.2 in this region. Please help convince me with you eloquent arguments.
I cannot agree more.
We have distinctly different housing stocks in Michigan from city areas to the “wilderness” of the Upper Peninsula. Certainly the discussion Rick Karg has introduced has merit on homes that air infiltration is a major impact on the SIR. But homes that are considered “Off-the-Grid” may never be candidates for forced venting.
It simply amazes me how we went from discussing “cost effective” air sealing a couple of years ago to air sealing to levels requiring forced venting today. We have been working with auditors at the agency level to better understand what the data means. In the rural areas it may be best to limit air sealing to levels that do not require forced venting for ASHRAE compliance to air sealing in urban areas as SIR driven and provide venting. I have some concerns that an exhaust only system may not have the good air quality make up drawn in especially with a crawl we cannot adequately isolate. But the cost of a combined HRV unit is well above the DOE H&S limits. Our State of Michigan utilities do not want to fund what they classify as “H&S” measures.
These are challenging times to get our Weatherization program to address energy savings with limited budgets from governmental and utility funding.
I hope our program survives long enough to learn how to adapt to these regulations
Russell W Glasgow
In the end we are all shooting for efficient, comfortable and healthy homes. “Seal Tight, Ventilate Right” is certainly a mantra we have subscribed to here in Vermont for some time. We view airsealing and mechanical ventilation as a package deal necessary to successful weatherization projects but in the end 62.2 and WAP just feels a bit like a square peg/ round hole scenario.
We have long targeted .35 ACH and an ability to keep indoor relative humidity levels in the 30-50 % range to limit the amount of bad stuff that grows when relative humidity levels creep outside of those ranges. Airsealing and Mechanical Ventilation as a package are inherent in that pursuit.
But an essential part of maintaining a healthy home is client education. We’ve had much successes educating clients on what to look for on their $ 5 humidity gauges, the importance of using a $ 5 shower squeegee after they are done in the bath, and then to use a quality fan when it will provide tangible benefits.
If the home is a bit below min. tightness limits, Two speed fans w/ motion sensors work very nicely to induce some extra airflow until high speed exhaust is really needed. These are all things that can be explained and easily understood by our clients.
But unfortunately people (and eventually their fans) are turned off by an explanation of “It’s highly complex” and it’s tough to offer more than that with the 62.2 calculations. All the extra installed cfm capacity doesn’t help when it’s in the off position. On another note the more common sense approach offered up by 62-89 did fit DOE cost effectiveness guidelines nicely.
So I guess I’m just begging for someone to really sell me on 62.2 as a good fit for WAP. I don’t wish to be a naysayer, just want to ensure we are providing our clients with the best possible project outcomes (Efficient & Healthy Homes) at the most affordable price point.
This is a great thread.
It seems that some of the issues revolve around the fact that we are trying to apply new science to old, sometimes very old, housing stock and really are only able to partially weatherize. Sure we can air seal add attic insulation and a 90% furnace and then add another fan to meet 62.2. Are we sure it will work? And how does a Weatherization program absorb the cost?
Consumer education, is and isn’t an issue. There is no guarantee the persons living in the home will ever follow our instructions. We have all visited homes where a 90% furnace has been installed and the owner still has the thermostat set at 90 degrees. No harm done they just save 10% over the 80% they had. But what if the owner shuts off the fan or the fan decides to quit and now the home becomes unsafe due to moisture and air quality because it was sealed tight? Where will the blame be put? Will we need legal documents to protect the programs?
Maybe it isn’t an issue but there sure seems to be enough concern across the country to warrant more discussion.
Another personal opinion –
I agree that some of our homes are excellent candidates for complete and unadulterated ASHRAE 62.2 scope of work. And when those homes are occupied by intelligent energy conscience persons/families it truly is a win-win situation. BUT…that is not the case all the time, half the time, occasionally. We conduct our audit, we provide client education on controls and when to turn on and when to turn off appliances. But I still have monitored homes with a furnace thermostat set at 90 a client complaining they are always cold. The kitchen gas range door open and all four burners on. I immediately look to my CO meter to determine the amount of toxins they have produced by using an appliance incorrectly. But by gosh and by golly they have a bath fan in an upstairs bathroom able to pull the toxins into the sleeping areas of the home.
I believe we can use the ventilation standards listed in ASHRAE 62.2 in some dwellings. Not all. The devastating element which we all would share is not one I chose to be party to.
I do chose to enforce ASHREA 62.2 only when I do have a prime candidate living in a dwelling which would benefit the resident as well as produce a good/GREAT end result I want to see reported to DOE.
Now my personal opinion is not going to impact my violating a Direct Order from DOE where I am required to apply ASHRAE 62.2 standards, but I do consider worst case scenarios. And that does impact my personal opinion on this subject.
That is it, have at me.
Lots of questions…
Matt asked how to keep people from turning the fans off when it is cold. Answer: don’t put it on a wall switch. The standard does not require a wall switch. The standard says “Readily accessible override control must be provided to the occupant” and then ALLOWS a switch to be that control. A breaker panel is also typically a readily accessible override control. We want them to be able to shut it off when there is bad outdoor air (think of wildfire season where they have those) but that doesn’t mean that we have to put in a wall switch. When it comes right down to it, of course, we cannot absolutely force people to use them – if they are really intent they can always cut the wires. We also can’t force them to do anything else, like change filters, use a CO alarm, keep the fan switch on the thermostat on “AUTO”, etc.
Matt asked about how to deal with wood burning stoves. Answer: it is a combustion appliance, use combustion safety testing. Also, keep in mind that the standard does not require an exhaust fan. If you are worried about the wood stove use a different strategy than exhaust.
Matt asked about what happens when the fan fails. As I said in my previous e-mail, the good quality fans required by 62.2 are pretty robust and many have been running for well over 10 years without failing. I have been looking for the example of a fan that is less than 1 sone failing in a few years and I just haven’t gotten those anecdotes. Contrast that with components in furnaces, not all of which ever get dealt with.
Russ also mentioned a concern about exhaust fans in certain houses. Again, if you are really concerned about the effect of exhaust in a specific house (combustion safety, clear unsealable connections to “bad” spaces, etc.) put in supply or balanced. You don’t have to put an exhaust in. I think Wisconsin’s experience is that about 96% of the fans they put in are exhaust. The fact that it is not 100% means that they are able to take into account those cases where it isn’t a good idea and do something else.
Josh mentions client education. Absolutely correct. People use systems they believe are important. One of the major focuses of the call yesterday was this subject, the need to put together a simple-to-understand client education fact sheet that explains the purpose and value of ventilation. People use furnaces despite their cost because they have decided that being warm is important enough. Why do we insist on warm air but not healthy air?
General concern about applicability of 62.2 to WAP. First off, it does account for climate differences. For the same CFM50 house, less fan flow will be needed in upstate NY and the UP than in Knoxville. So it takes that into account. Next, it allows for a range of different solutions – you don’t HAVE to use exhaust. So if your climate (or a specific house) is one where one solution isn’t a good idea use a different one. Next, we get to take a credit for remaining infiltration – thereby making it so that a leaky house doesn’t need as much (or any) as a tighter house.
As for “when the fan fails”, let’s leave aside the point I have made above about fans not failing very often. In my opinion we should never leave the house in a condition known to violate the current knowledge simply because we don’t think people will fix it if something goes wrong in 10 years. How many of us don’t put in furnace filters because they think people won’t change them anyway? How many of us don’t install 90+ furnaces because we are concerned the homeowner won’t replace a failed condensate pump? And are we on the hook for a new furnace when they didn’t do the maintenance required to keep it operating properly? No. Now let’s say the fan does actually fail. Let’s compare what happens now vs. what that result would be. Now we don’t install a fan, and we stop before the BTL/MVR/etc. If we end up still above that obsolete value, but because of the 62.2 calculation we need a fan, but it fails, then we are no worse off than we are right now today. If you are worried about that condition then you should not be happy with what we are doing now. (In other words, for many homes now we are effectively installing the “failed-fan” scenario.)
Next point: air contaminants. There are a lot of contaminants in the air: sometimes there is excessive moisture (usually occupant-generated), CO2, CO, formaldehyde, radon, VOCs, NO2, particles, odors. Here is the list of what 62-1989 was designed to deal with: odors. Somewhere along the way we got smarter and realized that there are more things in the house. People may ask “where are the bodies”. Not every indoor air problem is characterized by a dead person. Constant exposure to low levels of contaminants that we can’t even detect ourselves can lead to a degraded quality of life, children not learning as well, etc. There is actually a fair bit of literature from around the world suggesting that we really want a minimum of 0.5 ACH and that if we have less then there is a noticeable decrease in the quality of life and the health of children – this is approximately 62.2 plus another 50%. We obviously are not going to that level (either WAP or 62.2 itself) but to not do even the 62.2 level makes it worse. Also, as has been mentioned many times before, Wisconsin (a state noted for having a few cold days each year) has concluded that 62.2 is a benefit just on the CO2/humidity side. Their studies did not look at the other contaminants that are more dwelling-based than person-based, but it is not like we don’t have measured field data to support the use of 62.2.
One of the purposes of 62.2 is to make it so that we don’t all have to become health professionals or environmental health experts, trained to make determinations about levels of formaldehyde, VOCs, etc. I don’t want assessors going to houses and saying “I didn’t see condensation on the windows so we don’t need a fan” when there are other things to worry about. And I don’t want them having to make assessments of these other contaminants.
I don’t make any money from fan sales, I don’t make any money from 62.2 sales, I spend a LOT of time on 62.2 and representing WAP concerns to the committee. I have become convinced through the literature that it is an important thing to do for our clients, and that it is flexible enough for WAP and for us to avoid disastrous situations – for example, put in a different type of fan. We may not WANT to have it be the right thing to do because of the cost, and we may WISH that the old standard actually addressed the issues that today we know are there, but my view of the current reality is that unless we do a comprehensive per-house evaluation of contaminants known to be of concern and do a per-house performance approach (which is actually allowed by 62.2 as well), the prescriptive 62.2 approach is our best bet.
Bravo!! Marcia. Well spoken. When it comes to client ed, I'm lucky if they change the furnace filter once a year.
Paul, Great points all. One more obnoxious question; how many languages will you be printing your client ed packages in? Using a fast count, I'm looking at minimum of six. Matt
This is a really great thread. I don't have the call notes ready for distribution yet, but wanted to put things into context re: how the conversation started.
On our call, it was opened up to talk about anything related to 62.2 that was on people's minds. There were 23 of us on the call, and the first thing that came up was the need for some communications materials that could be used with clients (and installers, etc. if buy-in wasn't there yet) to explain the reasons for and benefits of ventilation. I will follow up on that.
Of course, we all know there are a lot of other things going on with ASHRAE 62.2, and this thread is getting to those. From following the e-mails, I see 7 categories that we're getting into. Of course, they all inter-relate, but maybe we can start populating some sort of matrix for ease of organization:
Bundle air sealing and ventilation into a “controlling airflow” packet and calculate energy costs vs. savings
Quantify healthy homes related benefits related to good IAQ
Client Education (including education for installers, program staff, etc. to get buy-in)
Must be clear and simple
Include cost/benefits (users input regional data to populate formulas and get locally valid numbers for their materials)
4 versions - by strategy (exhaust, balanced, supply, mixed)
“Typical” Natural draft appliances
Other IAQ Issues
Revisions to the Standard to better address retrofit situations
Next committee meeting is in a couple weeks, so we should consider this and let the Pauls and Rick be our representatives
Fan longevity, issues when it fails
Safety of Installation
Asbestos in building materials
Do you agree with the bolded categories for a way to organize our thoughts? Let me know. I'd like to set up a spreadsheet to keep track of our conversations, the questions that come up, answers, etc., and I want it organized in a way that makes sense to you all. As I said, there will be some overlap, but it would be something to work from.
Keep on keepin' on,
I have an issue that I’m not sure has been addressed yet. I would like to see a practical application of the standard. I know that Wisconsin has been using a version of 62.2 for a while, and I hear you folks when you discuss the four basic methods of ventilation that can be put into a home, but I’m more interested in real world solutions that are in use today.
I think part of the problem with getting buy in from everyone is that this is a semantic discussion. Where’s the beef? Where are the pictures of installations, controls, wiring, etc.?
We know as professional trainers that a picture is worth a thousand words, well, I’d like to see some pictures of installations and some discussion of alternatives and some of the ‘whys’ and ‘wherefores’ of what was done.
We know that education is the key to success in any endeavor, and we certainly are getting an advanced degree in indoor air quality issues and solutions, but…You can’t learn to ride a bicycle from a book. So someone grab the back of the seat and let me see how this standard is being implemented in something other than a graph in a PowerPoint presentation, please.
Graphically challenged, I remain,
The discussion shouldn’t be Air Sealing vs. ASHRAE62.2 it should become Air Sealing plus ASHRAE 62.2
Wow, an excellent discussion by all! I agree with Joshua Larose in terms of the square peg/round hole analogy, and getting DOE fully on board is essential. Finally, BPI will stop testing to 62-89 - soon. Thankfully, the new pilot certifications will use 62-2010. Thanks I am sure go in part to Paul Raymer.
i am not sure about going down this "rat hole" concerning Energy Star, but here goes..........My question has to do with a new home, and when it is determined to become an existing home. My new home is very over ventilated in terms of the new standard, which takes into account no cfm50 leakage, or what is in the home for ventilation, such as bath fans, kitchen hoods, etc. We have a modest- okay CHEAP fresh air intake system, but are still really overventilated. This is a throwback to the "super good sense" home approach. Fresh air damper tied in with AHU and exhaust fan. When conditions/temps/humidity inside and outside are relatively close, this is not a problem, probably less than 25% of the year. And, the problem is not as noticeable in the warmer months as in the winter months. I am on the western side of the Cascades, but on those mornings where the OAT dips pretty low, you are in effect bringing in this OAT into the house. As you can imagine, having cold air blowing from the duct system does not make the homeowner happy. In doing ductwork and heat pump inspections, I cannot tell you how many of these fresh air dampers have been disabled, mainly due to consumer complaints/comfort levels, and this is often the recommended fix by many a contractor and so-called building scientists in the region. In a house of about 2000 sf and leakage under 850 cfm, it doesn't take much to create a negative pressure situation ( no CAZ issue, as appliances are electric and outside of the living space. ( Thanks BPA and the Columbia River System!) We will be looking into a balanced system for the home, and a make up air damper for the kitchen hood. the only remaining big fan culprit is the dryer.
Maybe I am just missing the point, which happens from time to time. I hope I am not adding negatively to the issue. As Paul F. said, the exhaust only fan is not the only solution, but by far probably the lowest cost. air out = air in, but from where? Unless you control WHERE the air is coming from, and what temp and humidity it really is, are you really controlling the air? Until building codes start to come up to speed, such as a window in a bathroom negating the need for a bath fan, there is another battle we will have to fight.
In terms of categories, first and foremost in my opinion is Risk Management. The other is Cost. Several others that Kelly proposed can stand on their own.
On managing risk and if we presume for a moment that the prescriptive approach to 62.2 is “our best bet”, how do agencies provide safeguards for their client’s well being and reduce their own exposure in the process? Here’s a handful of possibilities, some of which have already been expressed in this thread:
The wrong things wrong – improper installation of an HRV that probably should have been an ERV to begin with; installation that doesn’t take into account the impact on woodstoves and other natural draft appliances.
the wrong things right - good installation of an exhaust only system in a hot humid climate, good installation of exhaust only system in Vermont. (Really?)
the right things wrong – improperly balanced system, miscalculation of venting requirements, properly sized system but no verification of actual flow rates
I think it would be worthwhile to inventory the pitfalls by reaching out to those with experience in the installation of these systems. And not just in Wisconsin. I think we need test beds in a variety of climates with different systems. Good training in real world situations (as Adrian mentioned) and logic charts are going to be critical to success. But there’s much more to it than training alone, not the least of which is the need for increased vigilance through strong QC and program management from the top down.
Then there’s this issue of cost first mentioned by John. I think we need to get a grip on the true costs to the program. On whether the overall benefit outweighs the cost, I’m not even going to go there. I’m a lot more concerned about whether we will have the resources to pull it off. This is at least as big if not bigger than blower doors, zonals, IR or anything else I’ve seen come down the pike in WX. Those technologies have demonstrated tangible benefits on the energy side. It took a decade or more to get most people geared up and relatively competent.
“Taking control of airflow” as Rick put it, is a very elegant approach and one that has the potential to make our homes perform like the awesome systems we want them to be. But the wholesale implementation of 62.2 is not without a lot of inherent risk is all I’m saying. The buy-in is a whole other issue but the question is, do we have the will to manage the risk effectively.
Oh, and about those T shirts, I’d prefer to have one of each. Sometimes I’m a fan but I also like to vent.
Bill Van der Meer
And another thing . . . .
This may seem a bit off the track but I was at one of those high end committee dinners the other night and the guy across the table thought his filet mignon was too rare. He wanted to trade. And of course it occurred to me that this was just like ASHRAE 62.2! Not everyone likes their filet mignon medium rare! Some people like it rare. Some people like it well done. Some people are vegetarians and don’t like meat. Some people would prefer fish. Many people would like filet mignon if they could afford it.
The 62.2-2010 Standard is amazingly flexible. As Paul F said numerous times, you don’t have to use an exhaust fan. You don’t have to use an HRV or an ERV. But whatever you use it has to be installed properly so that it works. I think the fact that 62.2-2010 requires that the installed ventilation system be tested to make sure they work is awesome! I was teaching a ducting class all day today and one of the students proudly said that he has been installing HRVs and ERVs for 10 years. I asked him if he tested them and balanced them. No, he admitted. They never do that. (By the way, when you put in a 90% furnace do you upgrade the delivery system/ducting at the same time?)
And another thing, 62.2-2010 is a system! Just like a house! If you pull one thing out, you’re going to affect something else. How many ventilation systems are documented? How many ventilation systems are tested? We’re working on the combustion safety thing, but even now there’s something in the standard. How many people read the whole thing? (It would certainly be nice if ASHRAE didn’t charge $54 for a copy although you used to be able to read it on-line for free. Anyone know if that’s still true?)
Everyone who teaches this stuff knows that a house doesn’t leak the same way every hour of every day. It’s variable. Right? Do we breathe same way every day? Pretty much. It’s a pretty constant need. So how do you satisfy a constant need with a variable source? The only way is to constantly exceed the need. The house has to constantly leak more than we need to breathe – and run through our combustion appliances and our clothes dryers.
It scares me that there is so much resistance among us as trainers to implementing this standard. I can tell you one thing, if a better product is needed to make this easier, the manufacturers would leap at the chance to make it. But I remember when Panasonic started selling quiet bath fans and the other big fan companies said that they would never make it! There are some spectacularly quiet, energy efficient fans on the market. There are HRVs and ERVs with ECM motors that last for years and years and systems that have built in balancing dampers and pressure taps. There are some extraordinary controls. The test equipment is getting better and better. We can do this thing! Breathing fresh air is a good thing!
I spent the day traveling back to DC and was reading with great interest 20+ incredibly thoughtful and insightful comments on this issue of 62.2 between flights. Don’t worry – I won’t even begin to step into this conversation – I’ll leave that to the professionals…
But, I thought I would share (now that we are at the end of the day and the comments have slowed) one thought. What struck me is how this conversation epitomizes the purpose intended when this group was formed almost 7 years ago (June 2005). That today, of all days, this group is having such a lively, informative, and challenging exchange is particularly poignant as three years ago today, we lost our friend Alex Moore who spearheaded organizing the nation’s weatherization trainers. I think it is quite a tribute to someone that many of us loved well.
I am certain he would be (or perhaps is) quite pleased that this group has grown in size and depth since those handful of trainers first agreed to work together to develop the core competencies. So, for those that are still reading email and need an excuse to grab a beer… Here’s to Alex.
Cynthia Simonson, SMS
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Matt Hoots, SawHorse, Inc.
Carl is one of the most dedicated people out there in the advancement of green building. As a consultant, he is passionate in his approach to building science. I would recommend him if you need help from a green building consultant, but only if you want the best. (read more)