Need help choosing a water heater

[Dana]

Thank you all for the feedback and advice. We just placed an order for the Thermodrain B 42 model. I will post pictures and feedback once we have it installed. Should arrive before Wednesday. Planning on installing it over the weekend. Anyone have any tips before we do our installation?

Making it as close to vertical as possible is important for getting the rated performance out of it, since once its off-axis there is less total surface area of the water inside the drain in contact with the surface for the heat transfer to take place. A couple of degrees isn't an efficiency tragedy, but 5 degrees of tilt will make a measureable difference.

Be sure to tee-off the output to feed BOTH the HW heater and the cold side of the shower, or it's a ~20% or greater hit in total peromance.

Beyond that, installation isn't difficult- it' doen't take a master-plumber to get there.

In most cases it's not worth bothering to insulate the output of the heat exchanger, since it's really tepid-water, not truly hot, and the losses even to unconditioned space is pretty low. I'd assume that in an Ontario location both the drain and HW heater would be located in a semi-conditioned basement(?).

[Dana]

Buy from EFI, and you get a much lower price for any of their listed than Sears, Home Depot, or direct from Renewabilty.

You have the link, their phone number is on it, and yes, the published prices are honored by EFI. The 3x48" is $471.50 + shipping-only, no handling charges and it's NRCan listed efficiency is 47.3%, about the same stated efficiency as the TD348B at about $115 more.

It's your $115, spend it any way you like, just don't shoot the messenger when I tell you how to keep it in your pocket, eh?

[jadnashua]

FWIW, list prices on most things is not necessarily a good indication of street prices unless it's a monopoly (like say Apple products or Bose - you want to sell one of those, you sell it at the agreed price or you can't get the product!). Another FWIW, my house has LOTS of soldered joints in it...I don't use that as an indication of quality. If it doesn't leak when you first apply the water (and the things we're talking about are testing in the factory after being made), it's not likely to leak afterwards. Copper is a MUCH better conductor of heat, so breaking the water flow into smaller paths that are in more intimate contact with that heat exchanger has the potential to work better. In the smaller passageways, the water is never very far from the copper. In a flowing liquid stream, you don't get much of any convection, so it is conduction and temperature difference that make the thing work.