Go Back   EcoRenovator > Improvements > Conservation
Advanced Search

Blog Register 60+ Home Energy Saving Tips Recent Posts Search Today's Posts Mark Forums Read

Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 03-01-10, 11:49 AM   #1
Supreme EcoRenovator
AC_Hacker's Avatar
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,002
Thanks: 303
Thanked 712 Times in 532 Posts
Default DIY Grey Water Heat Recycling...

There is an interesting entry in Wikipedia on Water Heat Recycling.

This photo is shown:

The article states:

The retail price for a domestic drain water heat recovery unit ranges from around $500 to $1,000. For a regular household, water heating is the second highest source of energy demand. The savings in energy results in an average payback time for the initial investment of 2-10 years.
It seems to me that someone could duplicate such a device for much less than $500 to $1000, and the payback would be much shorter.

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:

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?



Attached Thumbnails
Click image for larger version

Name:	water heat recycling.jpg
Views:	13731
Size:	30.6 KB
ID:	615   Click image for larger version

Name:	GFX_01.jpg
Views:	10392
Size:	30.1 KB
ID:	616   Click image for larger version

Name:	GFX_02.jpg
Views:	9588
Size:	34.3 KB
ID:	617   Click image for larger version

Name:	GFX_03.jpg
Views:	10699
Size:	55.0 KB
ID:	618  

Last edited by AC_Hacker; 03-01-10 at 11:51 AM..
AC_Hacker is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -5. The time now is 11:37 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Ad Management by RedTyger
Inactive Reminders By Icora Web Design