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Old 12-15-12, 09:50 AM   #50
GaryGary
Apprentice EcoRenovator
 
Join Date: Nov 2008
Location: SW Montana
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Originally Posted by GaryGary View Post
I was in Home Depot this morning and checked the alum flashing -- they have 50 ft rolls 14 inches wide for $43 -- 58 cents a sqft. Not so bad.
The Corplast is about the same price per sqft here, but you get twice as much HX area from a sqft.

I think I will give the David M. HX (or a variation on it) a try for the dryer and see how it goes.

For the edge spacers, I'm thinking about taking a plastic lumber deck board and ripping it into half inch (or a bit less) strips to make waterproof edge spacers. Does this seem like a good idea? Any other ideas for the edge spacers? It would be nice if the spacers did not require a table saw to make.

Gary
Decided to try a sort of throwaway prototype to see how well the dryer heat recovery HX works before trying the "production" one.

When I ordered the twinwall glazing for the greenhouse, it came packed between two used 6 by 9 ft sheets of twinwall -- I've cut these up into eighteen 3 by 2 ft panels, and patched the holes with alum tape. Started to assemble them into the HX stack last night, and it seems to be going well. Hope to do some more on it today. Its not so elegant, but its a lot of heat transfer area, so maybe it will work.

The first hookup will be running the dryer exhaust through one side of the HX then outside and with the dryer fan doing the pushing. A small blower will push room air through the other side.

If the first try gets good recovery, I'd like to go to having the 2nd side of the HX air path pull air from outside, through the HX, and then into the laundry room near the dryer. Idea being that the dryer will get the preheated air from the HX. This should allow the dryer to use less heating element time, and also keep the dryer from pushing furnace heated room air outside??

I found this paper posted earlier by Fornax to be quite helpful:
http://www.ewp.rpi.edu/hartford/user...0Exchanger.pdf

They also used a twinwall heat exchanger stack with a lot of heat transfer area and got efficiencies up close to 90%.

edit -- corrected the link above -- I think it works now.


Gary

Last edited by GaryGary; 12-15-12 at 02:04 PM..
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