Comments on: ASHRAE 62.2 Committee Chair Predicts Confusion & Frustration from BSC-01

By: Curt Kinder

Curt Kinder — Fri, 09 Aug 2013 11:44:36 +0000

None of $1. $3, or $5 per
None of $1. $3, or $5 per week is unaffordable...but why are we asking folks to drop $1,3,or 5 without being able to definitely state the clear benefit of doing so?

Where's the science? This thing looks like just so much spaghetti flung at a wall, hoping some will stick.

I'm an HVAC guy. Many in my tribe upsell all manner of putative IAQ improvers such as UV lights and electrostatic filters.

My stance is that if you think you need those things, let's talk it over with your allergist or MD and then mutually arrive at an agreed solution rather than me purveying "buy-or-die" upsells. Absent that, lets just go with a $200 deep filter bay that maintains good airflow, clean air to the coil and conveniently long change intervals and then call it a day!

Make a living, not a killing.

By: John Semmelhack

John Semmelhack — Thu, 08 Aug 2013 20:50:11 +0000

Thanks, Paul &
Thanks, Paul & Allison for the discussion.

Regarding the Nordic climate ventilation study - the air changes per hour should be 0.5, not 5.

By: Paul Francisco

Paul Francisco — Thu, 08 Aug 2013 09:31:46 +0000

You can always come up with a
You can always come up with a counter-example. Doesn't mean it should be used as the basis for everything. There are a lot of homes that use the $1/therm gas in 90% units (that actually measure out at 90% - it is quite common). The oil house does use more, I agree. You also save more by doing good air sealing. The people in that oil house also deserve good air quality just like anyone else.

I am willing to do the math. Otherwise I am just guessing. For the oil house in Chicago running a 50 cfm fan the heat cost is a little more than $150/yr, about $3 a week. The fan motor cost is still $10 for a low-watt exhaust fan (a lot more if you use the furnace fan).

I am assuming you are saying that there are 11 manufacturer-affiliated people on the 62.2 committee. That is not correct, at least as far as voting members are concerned. And of the manufacturers on the committee there are only 3 that have any relation to ventilation fan manufacturers even if you stretch the definition.

The fact is that the cost of running the ventilation is less than a monthly trip by the family to McDonald's for combo meals, for very many people. People get caught up in the huge-cost-to-the-homeowner argument, usually without doing the math.

It is fine to discuss/debate costs. That is a real part of the cost/benefit analysis. But if we are going to debate costs we should be honest and clear about what those costs are. People can believe that $3/week is unaffordable. Fine. But let's admit that's what we are saying.

By: Curt Kinder

Curt Kinder — Thu, 08 Aug 2013 05:58:44 +0000

Buck-a-therm Nat Gas burned
Buck-a-therm Nat Gas burned at 90% efficiency must be nice. Ask someone paying $3.50+ per gallon of No. 2 fuel oil at sub 80% efficiency how they feel about venting that same amount of heat.

Ask the same question of rural folks burning pricey propane...If the hapless pollsters split up and zig-zag smartly while running back down long country driveways they'll dodge MOST of the birdshot headed their way.

Don't get me started on ACTUAL furnace / boiler operating efficiency compared with nameplate AFUE.

I don't care to do the math as to the added operating cost of doubling my own contribution to my neighborhood's outdoor cooling all summer. It probably isn't too bad given my own system's efficiency, but I'd guess that it would shift the latent / sensible load fraction so as to kill my deeply cherished summer-long 45% RH.

Restoration of that 45% RH would likely then require a trip to my neighborhood central dehumidifier store. Do you suppose anyone on the Committee to Require Added Purchase Of New Utility Systems (abbreviated C------S) could recommend a good model? Member list includes 11 affiliated with "manufacturers"...surely one could help us out on that.

Does anyone else sniff foxes in the hen house?

By: Paul Francisco

Paul Francisco — Wed, 07 Aug 2013 02:44:01 +0000

My $50/year estimate includes
My $50/year estimate includes both the fan energy at $0.10/kWh for an 11 watt fan plus the heating energy based on $1/therm using natural gas in a 90% efficient furnace, with a little extra for some cooling. The fan energy itself for an 11 watt fan is under $10/year. I don't think hundreds of dollars a year for much of the country is correct.

Attic or crawl space ventilation don't add to a home's operating costs? I disagree.

There is always a battle between performance and prescriptive. In 62.2 you can do a performance option though the bar will be high. The whole reason for prescriptive options is so that we don't have to think too hard or spend a lot of time - we can just do something that gives us cover. It'll be wrong a lot of the time, but it should prevent most major problems and can be done expediently.

By: David Butler

David Butler — Tue, 06 Aug 2013 23:49:13 +0000

+1 Curt

+1 Curt

@Paul, $50/year might cover fan energy in Chicagoland where electricity is less than $0.08/kWh. It's maybe double that in New England and triple in Calif. And that doesn't include the impact on annual heat/cool costs. A total impact of hundreds of dollars annual is a fair assessment for much of the country.

Re: one-size-fits-all codes... Well, there's a difference. Other 'club fisted' prescriptive codes don't add to a home's operating costs. Also, there's no performance alternative for ventilation standards.

It's a tough problem, and I don't have all the answers. But just at a time when residential codes are beginning to incorporate & enforce ventilation standards (based on 62.2) is probably not the best time to make such radical changes in the calculation methodology.

In particular, shifting the ventilation credit from default to optional (along with the corresponding big increase to the baseline rate) may seem reasonable since the IECC now requires blower door testing. However, I'm sure you're aware that a growing number of states are opting out of the BD requirement. This is likely to lead to many grossly oversized ventilation systems.

By: Paul Francisco

Paul Francisco — Tue, 06 Aug 2013 18:27:25 +0000
Andrew: I am wondering what
Andrew: I am wondering what you think are "all the other issues that come up from a non balanced system" that I am "essentially ignoring".

Curt: I would totally support a control that turned the ventilation off when the windows were open. I have seen that sort of thing in action before, where the wall A/C would not come on if the window was open. Made sense to me. By the way, 62.2 does not prohibit something like that. 62.2 is a minimum standard - you can always go above minimum.

Concern about costs: In Chicago (which I realize is not Fargo but nobody confuses it with Orlando) a good 50 cfm exhaust fan would cost the occupants about $50 a year, about $4 a month. This is one area where exhaust fans do have an advantage - they are inexpensive to run. Maybe you don't want to use an exhaust fan, perhaps because of combustion safety concerns or because the house is really tight and could use some mechanical mixing? Fine, use something else. It will cost a little more in the energy directly tied to the ventilation but it serves other needs.

More "one size fits all": How many "code" requirements are NOT one size fits all and are properly sized for everyone? Attic venting? How many houses don't actually need 1/300? (Probably most.) Baluster spacing? Codes are rife with requirements that prevent the worst problems the vast majority of the time, and are overkill for many houses. I actually believe 62.2 is more flexible than many code requirements because it allows you to meet the requirements in any of a number of ways - you just have to be smart enough to figure out which way is best for your case.

By: Curt Kinder

Curt Kinder — Tue, 06 Aug 2013 17:04:31 +0000
A few thoughts: <
A few thoughts:

I was at first put off by the NSFC rating (Not Suitable For Contractors) rating given early on, but I put on my engineer hat and soldiered bravely on.

The most frustrating thing about this whole debate is the obscenely high ratio between the potential costs relative to the paucity of available hard data supporting any standard rate or, for the most part, safe levels of contaminants.

Specifically, widespread forced adoption of any sort of ventilation standard could cost each home owner hundreds, perhaps thousands upfront and potentially hundreds per year in extra HVAC operating costs in extreme climates. That runs into billions pretty fast, and before you know it, we are spending real money.

I'm a controls guy - 22 years of industrial automation before tiring of commercial air travel. On day one our corporate instructor trotted out Lord Kelvin's maxim, which basically says that to control, one must first measure.

Very few of us would leave our driveway in a car without a working speedometer, fuel gauge, and at least a modicum of confidence that coolant, braking, electrical, or lubrication failures will be timely annunciated (with idiot lights, at least). Yet it is widely proposed to continually actively exchange certain quantities of air in and out of homes with only the foggiest notion of what we are trying to accomplish!

Warning / disclaimer: story without much hard data ahead...We (4.5 people) live in a comfortable 3500 SF 3ACH50 home. We run bath fans, range hood, clothes dryer now and then, only when we remember or feel like it. All aboard average no more than 1-2 sick days per year, usually less. Have we got the ventilation thing right? I have no idea, but I'd be hard to persuade to invest in fixing something I very much doubt is broken.

Consider the Tea Party aspects of this - remember the fireworks over the elimination of the 100 Watt incandescent bulb? Now some are proposing to mandate purchase, installation and 24/7 operation of an expensive device or system without data supporting the need nor controls to make it at all smart. If the Tea Party, or its (small) wing whose IQs exceed their shoe sizes, picks up on this, head for the hills!

I grew up in New England - it was SOP to have windows continually open for most of late spring, summer and early fall since we had no AC. Now, it is part of every deep energy audit we conduct to ask whether the home "operators" open windows during mild weather or let HVAC run year round. The split is said to be around 50/50, though I suspect in actual practice, frequent window openers are fewer than half in number. My point in bringing this up is to ask whether anyone could be serious about requiring a ventilation system to operate at any nonzero rate while windows are open? Really?

Are the members of the committees truly disinterested parties purely serving society, or do they hail from the halls of companies that would greatly benefit from mandated systems? I don't automatically discount the experience of experts from any quarter, but let's factor motivations and conflicts of interest, both apparent and real.

Don't get me wrong - I'm not against mechanical ventilation or standards. But before forcing billions to be spent on "dumb" blowers and at the same time undoing decades of energy conservation let's both learn more about the health aspects of indoor air quality and develop sensors to intelligently vary the rate the system operates. Oh yeah, let's also provide for shutting the thing off if the house is empty or windows are open!

By: henry slack

henry slack — Tue, 06 Aug 2013 06:45:30 +0000
Alison -

Alison -

Thankx so much for keeping this conversation going!

FYI, I'm aware of a few studies in concrete condo and apartment buildings where units were in the range of 0.1 ACH (and as low as 0.04) because we don't require ventilation in residences.

More significantly, some of these have radon outgassing from the huge amount of concrete, and levels of 12-16 are common (that's 3-4x EPA's Action level of 4 pCi/L).

I'm presenting a paper on this at ASHRAE IAQ 13 in October. The original research is mostly by Bill Brodhead (who investigated several buildings) and Clark Eldredge at FL Department of Health (with Tom Pugh of FAMU?) who has over a thousand radon measurements on the upper floors of these high rises. I cite a few other papers as well.

Brodhead's solution: add some outside air for ventilation, typically to the kitchen. Even so, if you close the bedroom door at night, you might still get some elevated radon, he suspects.

By: Andrew Michler

Andrew Michler — Mon, 05 Aug 2013 23:28:56 +0000
I am beginning to see why our
I am beginning to see why our modern buildings are basket cases. If an ASHREA standard is developed with so many assumptions involved it would seem that they would error on a conservative side. The idea of saying exhaust ventilation is OK if you have many small leaks or one big leak or something in between is a touch radical to me. I think of walls getting soaked if there are small holes in the envelope. I think of a room or two that will be freezing or stuffy if there is one large primary hole. What if the home is next to a freeway or other outdoor pollution source? Then of course there's the energy penalty which always seem to take a back seat. That is a big reason why LEED buildings are eating much more energy than anyone thought. I believe Mr. Fransico makes an excellent point about ventilation at pollution sources i.e. bath, kitchen, laundry. He is essentially ignoring all the other issues that come up from a non balanced system. And that is a radical departure from what we know about buildings.

I would suggest that the unknowns in a typical exhaust ventilation "system" greatly outnumber the other options. And yet it is a safe guess that 90% of homes will be exhaust. Reading between the lines the statement about ASHRAE having a political side is shorthand for saying builders want the cheapest option possible, no matter what the consequences. So another decade of half assed houses.