03-01-10, 10:49 AM | #1 | |
Supreme EcoRenovator
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,004
Thanks: 303
Thanked 724 Times in 534 Posts
|
DIY Grey Water Heat Recycling...
There is an interesting entry in Wikipedia on Water Heat Recycling.
This photo is shown: The article states: Quote:
I also found that there is a company called GFX Technology that makes such a device. They have a PDF of performance curves located here. There's even a Bob Villa video . Here are other companies in the same business: http://www.renewability.com/powerpipe.htm http://www.retherm.com/ http://www.ecodrain.ca/ The important features I can see are: * counter-flow - drain water goes in one direction, incoming cold water goes in the opposite direction (larger 'delta-T', makes the efficiency higher.) * drain water flows in a thin film inside the heat exchanger - this assures maximum exposure of the hot drain water to the cold incoming water, making the efficiency higher. (question: is a special structure required for this to happen?) *copper construction assures good heat transfer. (question: is the coil soldered to the drain water pipe? * it also seems to me that encasing the whole assembly in insulating foam would improve the efficiency even more. I have seen projects where plastic 55 gallon barrels and long pieces of PEX are coiled inside to make such a system, but this compact copper unit seems to be elegant, compact efficient and highly buildable. Here are more photos of the GFX units: With domestic water heating being the second biggest energy use for homeowners, this seems to be a natural target for our efforts. Claims of efficiency seem to run as high as 50%, this would hold for fossil fuel use, and also for wood water heating, as well as for the size of a solar Domestic Hot Water (AKA: DHW) array required to supply DHW to a home or business. Best of all, no moving parts. Build It Solar has a relevant link here. Here is a link to a Grey Water Heat Recovery Calculator. Are the wheels turning? Regards, -AC_Hacker Last edited by AC_Hacker; 03-01-10 at 10:51 AM.. |
|
|
|