Does anyone here have any experience with hot water heat recycling units?  I've been doing some reading on them and I wanted to see what others know about them.

kwade, i remember reading something about reclaiming heat from drain water on http://www.builditsolar.com/

just my own 2 cents here, but anything beyond trapping the water in the tub or letting a pot of water come to room temp. on its own seems more complicated than its net return is worth.

holding tanks have been suggested but thats custom plumbing valves and probably a pump if its in a cellar.
one kitchen sink drain just for hot water, connected in with the dishwasher drain, run thru a length of register for forced hot water systems.  washing machine the same way but on its own.

the septic system probably benifits the most from the hot water by keeping the biological process more active in the winter. thats a savings alone.

The units i've been looking at are from LINK
A friend of my brothers has had one for over a year and swears by it.  I figured i'd do a little extra digging before i buy since I only personally know of this single home install.

We don't have a private septic, but my wife is a biologist.  As she puts it "Crap doesn't need hot water to breakdown.  If it did the woods would be full of thousands of years of deer and raccoon dung."

Anyways, if anyone has first-hand experience with these things I'd appreciate hearing from you.  It doesn't seem like there is anything that can go wrong, but I still perfer to find out as much as i can before buying.

Thanks for the Metlunh suggestion, but those hot water recycling loop pumps is not what I'm considering.  The distance between my water heater and shower is really short.  I only need to run the water for a couple of seconds before ther's hot water.

I guess when I wrote "hot water heat recycling" I should have referred to the more common name for these ReTherm things, drain water heat exchangers.  Anyone out there with first-hand experience with drain water heat exchangers?

>>>"Crap doesn't need hot water to breakdown.<<<

not hot water.....heat. if the woods remain frozen, so will the dung. the lower the temp., the slower the decomposition, as i learned in high school biology class. thats why your septic guy will tell you to keep a certain depth of dirt and lawn covering the septic system for insulation in the 'winter'.
 
my bad on the heat exchanger, i apologize. all i ever read about was home made contraptions that seemed like overkill for their return potential. i am still skeptical however about the claims they make in yearly percentage of heat savings. seems to me if they were that efficient, they would be more common place. but again, thats just my 2 cents.

The minimum temperatures that a septic tank requires is not my area of expertise. One thing I do figure though is that a the shower drains at about 40 deg C and the water coming into my house from the city is about 10 deg. If the heat recovery of that drain water of a full 2/3 that means the water leaving the house is now 20 deg C instead of 40. I doubt that's going to cause problems for a septic tank, but you know... i don't really care. The city looks after my crap, but they don't pay my heating bills.

So I guess I'm making progress on my evaluation. I haven't head any first-hand horror stories from anyone.

I'm going to go check things out at this fellas house on the weekend. I'll let you know how things looked.

i have been looking at 'grey water heat recovery systems. here is one i found http://www.theresourcestore.ca/Heat%20Recovery.php