Comments on: Down the Drain! — Heat Recovery for Your Hot Water

By: Daniel Beauchemin

Daniel Beauchemin — Thu, 15 May 2014 17:42:15 +0000

To get a better idea on the
To get a better idea on the savings potential for drain water heat recovery technology – you should try this calculator. The ThermoDrain TD342B is equivalent to the G3-40 product in efficiency.

http://www.ceati.com/calculator/ 

We manufacturer the ThermoDrain and send our customers to this website to get a better idea on what the savings would look like for their particular application. Each application has several variables and this calculator takes all in consideration including the temperature of the ground water.

Daniel Beauchemin
EcoInnovation Technologies
http://www.ecoinnovation.ca 
888-881-7693

By: Craig Senglin

Craig Senglin — Mon, 01 Oct 2012 00:12:52 +0000

Anybody ever compared the
Anybody ever compared the cost/savings of the GFX vs. simply insulating the hot water lines throughout the home? I'm all for reclaiming the heat lost down the drain, but the GFX looks less than optimal in most slab-on-grade construction and most retrofits. What about the extra plumbing material/cost required to run additional "cold" water lines to transport the recaptured heat. Then you have heat lost along those lines before making it back to the WH. The longer those lines, the less sense this solution makes, and the more potential for a plumbing leak/issue down the road. "Keep it Simple, Stupid", as the saying goes....

By: Tony G

Tony G — Thu, 03 Nov 2011 16:06:06 +0000

As mentioned, have a look at
As mentioned, have a look at a similar product http://www.showersave.net 

Not sure it is the same Allison?

By: Mike Legge

Mike Legge — Sun, 09 Oct 2011 10:56:32 +0000

Great idea. I have a tank
Great idea. I have a tank which collects all the water from the bath,washing machine etc. and recycles it through the the toilets( info@hldbc.ca). All the heat stays in the house and saves water.I have a sewer through my property and have always wanted to put a ground source pump on it. I was told this has been tried and the sewer froze-yikes! I guess the snow will continue to melt off the manhole covers. Cheers Mike Legge

By: Allison Bailes

Allison Bailes — Thu, 06 Oct 2011 03:29:23 +0000

Mike:
Mike: Thanks for the link! I'll check it out. I think I agree that 0.12 additional in the EF seems high. For modeling purposes, it's best to ignore the non-simultaneous uses to err on the conservative side. The actual use, then, would be better than modeled if any of the non-simultaneous heat is captured.

By: mike

mike — Thu, 06 Oct 2011 01:41:33 +0000

wow, add 0.12 to your EF?
wow, add 0.12 to your EF? that seems extremely generous. it is also a function of the efficiency of your heater, as some other commenters have noted indirectly.

interesting study here, with calculations to estimate savings: http://www.regie-energie.qc.ca/audiences/3637-07_2/DDR3637_2/RepDDR/B-12-GI-23Doc1-2_RepDDRSE-AQLPA_3637-2_28sept07.pdf 

re: simultaneity, the study states: It was concluded that DWHR devices only recovered energy during simultaneous water draws (showers) and that for modelling purposes all other water draws could be ignored.

By: Allison Bailes

Allison Bailes — Thu, 06 Oct 2011 01:11:56 +0000

David B.:
David B.: Thanks for your comment about your analysis on this for your previous home. I think the price of copper may limit the cost-effectiveness of these devices except in homes where people take a lot of showers. And yes, I neglected to mention that in/out simultaneity issue. Thanks for raising that point, but even when when the water heater's not drawing water in while the hot water goes down the drain, some of that heat may be recovered the next time someone runs hot water, unless it's a long time later.

Kyle A.: Do you list kWh/yr just as a general energy unit? Do they give the number in Btu/yr or GigaJoules/yr or m^3/yr if it's a gas water heater? I agree that the 0.12 added on to the EF is a bit imprecise.

Bob: That's a good question. Once I find out more about the numbers, I'll let you know here.

Robert D.: I'm with you on that one. Most homes have huge inefficiencies in hot water distribution and waste a lot of energy and water. Easy to fix in new homes with good design. Not so easy in existing homes.

Donald B.: Yes, thanks for pointing out that some of the heat still gets recovered even when the hot water's not running when hot water's going down the drain.

Tony G.: From your website, it looks like the one you're selling is the same as I described above, right?

Josh L.: That's what the raters in my class in Toronto told me they've been instructed to do.

John P.: Yeah, that could work. Now, can you make it cheaply enough to be cost effective? Will it take another tank? Where will it go?

By: John Poole

John Poole — Wed, 05 Oct 2011 19:31:36 +0000

Good point by David Butler.
Good point by David Butler. An optimization might be, when hot waste water isn't actually flowing, hold some quantity of it in an insulated holding tank. The supply coils could be immersed in the water in the tank. Then, when the held water drops below some optimum temperature (what ever that is), or more hot waste water starts to come in, release the old water. :-)

By: Joshua Lloyd

Joshua Lloyd — Wed, 05 Oct 2011 05:31:02 +0000

What about on-demand water
What about on-demand water heaters. Would your really add the 0.12 to the EF?

By: Tony Gordon

Tony Gordon — Tue, 04 Oct 2011 20:23:51 +0000

There's an alternative to
There's an alternative to this one. Some 20,000 homes in Europe now have it installed!We do have case studies for commercial applications also. Please do contact me to get them. Looking for distributors in US if you have any ideas?