[Greenbuilding] ERVs and windows

[Nick Pine]

"JAY WALSH" <jaywalsh at usa.net> writes:

> 3. Do not locate the HRV in a cold attic or similar location, and in 
> very cold climates be sure to provide for a connection of the HRV to 
> the homes drain system. This will be necessary for when the system 
> needs to defrost (which it will need if the outside temp falls 
> below -10 F).

Maybe the intake should be in a sunspace or air heater, with a sensor 
that only runs it when the house is humid and the sunspace is warm.

> 7. Have the system tested to insure a balanced supply and exhaust so 
> you do not create a positive or negative pressure in the house.

We might backdraft a 10' 300 F furnace flue if the fan can make more 
than 10'x0.075psf (1-(460+70)/(460+300)/62.33x12 = 0.04 "H20. Positive 
pressure seems OK, with a barometric flue damper. We might run a small 
intake fan in the liviing room at the same time as an exhaust fan in the 
kitchen or bathroom.

I wrote:

> If it's 70 F indoors and 30 F outdoors in the shade, (70-30)1ft^2xU0.3 
> = 21 Btu/h would flow through the indoor pane,

Oops. Shoulda been 12.

> would make it 70-21/1.5 = 56 F,

And 62.

Thin flat polycarbonate might be nice retrofit glazing, one layer over 
the outside of the original window and another replacing the window 
screen in the new storm window. GE's HP92W is very clear and might last 
forever. The 0.007 inch version costs about $1/ft^2 in 4'x100' 20-pound 
rolls.

Nick