Hello everyone!
We have been so busy with our bathroom renovation that we forgot to thank everyone who has posted comments on this site that help contribute to our projects success.
I would live to post some pictures but I am new at this and maybe I will find the time to do so in the next few weeks.

One of the major green features in our bathroom remodeling was the addition of a shower heat recovery unit manufactured by Ecoinovations. I was skeptical at first about the technology but got some readings using my Canadian Tire thermal red dot reader of incoming cold water of 48F and outgoing warm water of 71F while my daughter is showering. Too early to tell how much money I am saving.

We purchased the ecoinovation thermodrain TD348B shower heat recovery unit through the recommendation of our mechanical engineering friend who works for the department of energy and is very familiar with this technology.

With drainwater heat recovery (DWHR) it's as much about the showering performance as it is about the NPV on fuel savings.  At buck-a-therm gas it's not saving much, but never running out of hot water is good for family harmony, eh? With a typical gas-fired tank heater + DWHR you can pretty much never run out of hot water with 1.5-2gpm low-flow showers. That's not necessarily always a good thing- I had to dial back the occupancy sensor time  out on the bathroom lights to keep his showering times reasonable, but at least you'll never here the hollering from the less than comfortable spouse who steps into the shower after you.

If you're heating hot water with 20 cent electricity or $4/gallon heating oil the savings are pretty good.  The people who REALLY make out with DWHR units are the folks with monster-gusher 6 side spray luxury showers, since it can save them the cost of an second or super-upsized hot water heater, as well the ~50% reduction in water heating fuel used for showers.  In some homes showering accounts for less than 25% of all hot water use, but in homes with monster-gushers it's likely to be well over half.

EcoInnovation has a lower buy-direct price than the competition, but you can beat them fairly substantially on price/performance buying a competitor's product through EFI (headquartered in Westboro, MA).  EFI has liberal policies for opening up accounts (over the phone with a credit card works), which allows you to buy drainwater heat exchangers at their listed wholesale price (plus shipping no handling charges or markups from their Wisconsin facility.)  The competitor's 3" x  48" has been third party tested at 47.3% efficiency as listed on NRCan's rebate eligibility list  which is the same or better 47% manufacturers' stated efficiency of the TD348B (I guess that's about what you get out of a 3" x 48") but it is ~$115 less than the buy-direct price of the TD348B if you buy through EFI.  Not big potatoes in the whole installed cost, but still a substantial fraction of the raw hardware cost.

I installed a DWHR unit a handful of years ago (a 4" x 48" PowerPipe) primarily for the showering performance factor on my combi HW/space-heating to allow continuous & simultaneous space heating & hot water calls without running short of either, and without having to crank up a high-output burner. It's performance was critical in making that possible, and it's definitely doing the trick.

With tank nat gas and a .5 gpm showerhead, DWHR made no sense for me. Not even close. Plus I can also shower forever.

Yabbut, if you showered FOREVER it would probably pay off even at 0.5gpm flows, eh? :-)

The efficiencies soar at very low flows too- you'd probably be getting something like 70%+ efficiency out of something that ran 50% efficiency at the NRCan test parameters (2.5gpm at whatever incoming & shower head temps they specified- I'd have to look that part up).

But for sure, it would take a very long time to break even for most 1-2 person households heating hot water with natural gas at current US pricing.