4a. Re: Hot Attic

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Barb

I do not like fresh air intakes very much but prefer HRVs, which can be set and forgotten (except for cleaning and maintenance) if they are installed correctly. In many locations where air conditioners are used, they must then be supplemented with good efficiency dehumidifiers, to control indoor humpty problems in spring, summer and early fall. Modern 'supposedly efficient' air conditioners do not dehumidify well enough, even though that is what air conditioners are really for.

Depending on the location of your fresh air intake, it could have moved the balance point between inflow and outflow up or down along the inside walls of your house. In the cooling season, if the intake 'looked like' it were low down (a likely scenario), it would have been a massive exhaust down low and the house would have sucked very hard on the attic, bringing down all of the wonderful 'stuff' up there into your breathing air indoors - not too smart. Why is it that 'Americans' believe that if one intake helps, two will be better - that is not the way most people think around the world, where 'just right' in size is an accepted concept?. We Canadian Americans often think that way too. We are becoming more US American all the time.

By the way, the symptoms that you had remind me of massive mold exposure to mold, something I experience when doing some house investigations. When I am exposed to Stachybotrys chartarum, I also cannot think straight for days, often missing days of productive work. Yesterday I got a minor Stachy hit and I am as cranky as Hell! Sorry about that!

By the way. the house pressure DIFFERENCE was negative up top and positive down low. Only with large fans operating between the inside and outside (not circulation fans indoors) does the whole envelope see totally positive or negative pressure differences, then there is still the 'stack effect' gradient superimposed, so the effect is not uniform anyway.

Jim H. White System Science Consulting

4a. Re: Hot Attic Posted by: "barb1283" barb1283@... barb1283 Date: Wed Jul 26, 2006 10:28 am (PDT)Jim and other Air Quality people, I think I found at least one of the problems and it is doozey. I loved my fresh air intake so much I put a second one in last winter. It actually didn't make much improvement over the one but didn't seem to hurt either so I left it up. When I put it in though, it was experimental, and I didn't bother to put a damper in it and then forgot I left it out, so effectively I have had a 6 inch round hole in house without a damper that goes right into furnace/through cold air return. When it was real hot and humid out, I turned the fan off of 'constantly going', and on to 'auto', so fan was off a lot. When it was off, every register in the house was completely open to the outside through the hole going from furnace to outside. I guess this created a very big low pressure zone in house. Is that right? Maybe I'm confusing indoor air matters with the local weather report!! This perhaps pulled attic air down into house? Whatever it did, I felt awful, very weak, kept seeking out the sofa. Unusual for me. Anyway, I closed off fresh air intakes at the outside. After I closed off the two intakes, I started to feel better, so that was it. What it tells me though is that I do have attic air problem. What else could it be? I don't feel sick when I go outside, so it wouldn't have been outside air coming in. >> Barb> If your house were not depressurized by the stack effect and the unbalance between flow resistances, the fresh air intake would have not flowed at all, or flowed outward. Since it brought fresh air in, the house was depressurized at the effective opening height of the outside of the fresh air intake. You have a good, cold-weather situation,