Another follow-up to one of our posts reviewing the Energy Efficiency Evaluation Report we received under the ecoENERGY Grant program relates to the instantaneous or tank-less water heater:
ecoENERGY Report - Part 6 - Recommendations
Now, two aspects here:
First, we were surprised that all of our local utilities and quasi-utilities which sell water heaters do not appear to offer the installation of these types of water heaters to existing homes. We went on their web site and could not find any mention of this.
When I inquired over the phone I was told something which concerns me. I was advised that the installation of an instantaneous water heater is typically cost prohibitive for many older homes due to the expense of the retrofit / installation.
In new homes, the location of these types of water heaters can be planned before the home is actually constructed. However, in older homes which already have ‘traditional’ (for North America) water heaters, significant renovation is frequently needed for their installation, thus making the economics of their installation not very viable.
Second, I have come across some (to me) theoretical information that with the colder Canadian winters instantaneous (tank-less) water heaters may be challenged in providing hot water at the same temperature as would a ‘traditional’ (for North America) water heater.
The reason given was that fresh water entering a home in Canada (or the States in the northern regions of the United States) during the winter can be colder than fresh water entering a home in many parts of western Europe. Therefore, the theory continued, the same instantaneous water heater may work well during the summer but not as well in the winter……at least without a Drain Water Heat Recovery (DWHR) device to first warm the incoming fresh water.
We would appreciate hearing from our readers who have experience related to either of these two aspects of instantaneous (tank-less) water heaters, either from personal experience in their homes or from the marketplace. Please provide any clarifications or experiences by leaving a comment to this post or sending us an email. We thank you in advance.
3 responses so far ↓
1 Bill Lynn // Jun 29, 2008 at 8:38 pm
The house we rented in Belgium in 1961-62 (yikes, that’s 47 years ago) had a gas fired tankless water heater. We had to turn on the hot water fast enough to get the burner going, but much faster and the water came out cool.
Of course, the technology has undoubtedly improved since then.
In any case, I have some doubts about the energy saving of these things because for most of the year in Canada the heat lost from a water heater storage tank helps to heat the house (same for electric appliances).
So any energy saving only applies during the non-heating season.
An exception might be an inefficient oil or gas fired water heater where the losses go out the chimney.
2 Dan // Jun 29, 2008 at 8:49 pm
Hey Bill,
Thanks for the comment. Any and all are helpful as I am trying to make sense out of all this noise.
Not sure I agree (at least in our situation) with the comment “…for most of the year in Canada the heat loss from a water heater storage tank helps to heat the house”. We have an oversized 75 gallon hot water tank and when you touch the outside of the thing is not hot….it’s not even warm. So at least in our case the hot water tank does not help to heat the home.
I’m still trying to figure all this out before we call back the energy audit guy for the second and final energy audit to have him start claiming the Federal and Provincial ecoENERGY tax credits.
Dan
3 Bill Lynn // Jun 30, 2008 at 7:57 pm
Hi Dan,
That’s right - modern water heaters are so well insulated that they lose very little heat to the surroundings, but a standard recommendation is to add an insulation blanket or, in your case, install an instantaneous heater.
I do not see how either suggestion will significantly improve water heater efficiency, unless the existing water heater is the prehistoric type with an uninsulated galvanized tank.
Bill
Leave a Comment