Problem with winter dryness

[nicksanspam]

Here's my opinion:

Advantages Disadvantages

A) Natural leakage Lower first cost Higher fuel consumption More reliable in winter and summer Possibly better IAQ: Can't use HRV CO, CO2, H20 often Lower RH in winter diluted with a Wet insulation and drywall large flow of Possible wood rot, mold, fresh air and mildew inside walls No ventilation at all on still mild days

B) Positive ventilation More uniform fresh air and temp distribution around the house It's always easier to bring air in than to keep it out, turning B) into A) if needed...

Nick (who just got a call from two Lennox lawyers saying they may change the energy-savings claim on their humidifier web site "if it turns out to be inaccurate in the opinion of our engineers" :-)

[Bill Bonde ( ``And the Lamb li]

Isn't that what taking a shower does? How much energy is lost from evaporating and sending outside all the water splashed around in taking a shower?

[Rod Speed]

Nothing like as convenient as using a humidifier, stupid.

Who cares ?

[Bill Bonde ( ``And the Lamb li]

So you are going to vent the water vapour that you can get for free and pay to make more with a humidifier you had to buy? Your a genius, Rod!

If you just vent the house of that water vapour, that's heat going out of your house. If you are paying to heat your house, that is money going out of your house.

[Rod Speed]

Nope.

Nope.

You're a f****it, Blonde.

You quite sure you aint one of those rocket scientist fuckwits ?

I dont care how much is lost, because its a tiny part of the winter heating cost.

[Gary R. Lloyd]

An ERV would make more sense than an HRV, providing another plus in the form of humidity recovery.

Gary R. Lloyd CMS HVACR Troubleshooting Books/Software

[Gary R. Lloyd]

Gary R. Lloyd CMS HVACR Troubleshooting Books/Software

[Gary R. Lloyd]

Another real downside is price. What would be the payback?

Gary R. Lloyd CMS HVACR Troubleshooting Books/Software

[Gary R. Lloyd]

I should point out that I am by no means an expert on HRV/ERV, but I am not aware of any residential ERV which is recommended for subzero temps, because they freeze up. I included the above link to very expensive high volume commercial warm weather/cold weather ERV's just to show that it is possible. I suspect however, that the humidity transfer has a price.

Should someone come up with a residential ERV capable of economically transferring humidity in both warm and cold climates, these presumably would have a huge potential market beyond the deep south, and would go a long way towards justifying supertight construction.

Gary R. Lloyd CMS HVACR Troubleshooting Books/Software

[Rod Speed]

Nope. You'd normally save enough on the lower heating costs that better sealing produces.

Obviously that would vary with the location and how much heating is done.

[gerry]

I can not get the make/model info at the moment since I don't live in Maine. But ME certainly experiences subzero temperatures and residential ERV's are required in all new construction. The person I visited with one no longer lives in that house (or new construction) so I can't call and get the information.

One such unit is:

It uses a periodic defrost cycle below 23F.

"The ERV is equipped with a special energy recovery core which exchanges both sensible and latent heat with the fresh incoming air. The ability to transfer moisture however, allows the core to build frost to cold outdoor air in winter time. For temperatures below 23°F, the unit will automatically operate with periodic defrost."

gerry

[Ecnerwal]

I've always been more than a little suspicious that the units which try to transfer moisture between airstreams will also transfer other stuff (dissolved in the moisture) between airstreams, which you might rather exhaust. An obvious example would be ammonia fumes from cleaning products.

I'm also innately suspicious that this type of core is a better breeding ground for unplesant life-forms.

[Clarence]

While in Wisconsin we added 12 drops of bleach per gallon of water put into the humidifier to assure minimum possibility of live transfer. The Humidifier had ceramic plates to provide large evaporation surfaces and I used to have to soak the plates in vinegar once every three months to remove the lime deposits that formed on them. I know now that distilled water would have helped a lot for this, but there was no reference to the water purity in the directions with the humidifier. The did sell replacement ceramic plates though!

[Gary R. Lloyd]

In case you haven't noticed, what I've been trying to do here is to get you to present a case for your strategy that is based upon why this is good for the homeowner, rather than why it is good for your political agenda. I remain unconvinced.

At the very least, there should be enough *passive* introduction of outdoor air, be it through leakage or controlled flow, to keep people from passing out (over 5 CFM per person), and then pump in the rest.

And I am also not convinced that people outside of acclimated desert dwellers are comfortable and/or healthy at 20% humidity.

Gary R. Lloyd CMS HVACR Troubleshooting Books/Software

[Gary R. Lloyd]

Of course that's true. Nonetheless it is the question a homeowner is going to ask. What is needed for the discussion is a typical house in a typical location, with typical construction costs and typical energy prices.

Gary R. Lloyd CMS HVACR Troubleshooting Books/Software

[nicksanspam]

Pity. BTW, I'd call the information above unbiased, albeit my opinion, and that of many others. How would you change it?

Sounds good to me, on the coldest day. Airtightness costs money. Why overdo it? Those few cracks and crevices can be bidirectional air-air heat exchangers with a bidirectional fan in an indoor partition wall. BTW, extra air leakage also increases AC bills.

Pity. You might look at the ASHRAE 55-2004 standard.

With these "credentials," it's darkly amusing that you know so little about building science :-) I'm only one of thousands of engineers and architects around the world who recommend reducing air leakage in houses. You might correct your lonely arrogant ego-filled ignorance by taking an ASHRAE short course on ventilation or joining the Society of Building Science Educators (SBSE). They have a nice web site.

Nick

[steve]

Your many others are being challenged..simply address the issue...or dont.

Something we have been installing for years....

I am sure that Gary is more familiar with it than you expect. Do you own any of his books? Read any? Might be worth your time..and you might learn something new. I sure did.

Even more amusing is that many states have now relaxed, or will relax the standards of sealing a home. You are making one point, and overlooking others.

I think the only ego maniac here is you....thank God your ideas wont fly here...nor is there a contractor in this state that would allow you to design a home for him, when we have several here that are NOT sealed up tight as a drum, and the owners can claim power bills that have not exceeded $75 a month here...and we are talking fairly large square footage. There is a limit to what you want to do, and maintain a healthy enviroment.

[bill]

Well, you genius engineers seem to have IAQ problems and sick building syndrome everywhere, regardless of climate. When you fix your piss poor implimentation of IAQ that has caused more problems than it's solved you get back to us.

Step off your hobby horse Nicky. It's legs have been cut off.

[gerry]

I concur - the difficulty with "positive ventilation" is it isn't "positive", it's "active" and far from fail safe.

Controlling "passive ventilation" certainly is difficult, any minimum will likely be grossly exceeded under some weather conditions. At least it remains safe (death not being the sole criteria).

gerry

[bill]

Yeah but...

Nicky has a website or a magaz Bet he pulls a formula out of his ass trying to dodge this one.