[Greenbuilding] Low powered (wattage) water heaters availablethrough Hydro Quebec

RT rw_tom at ymail.com
Fri Dec 30 10:30:02 PST 2011


(Reuben's) adaptation with a bit more attention to ranking by importance  
and
creativity:
[snip]

>   - Keep your water heater’s temperature at 49°C (120°F).

Probably not the best idea to save a few pennies, recalling a previous  
discussion on this List where one Maritimer had the heebie-jeebies about  
the high potential for legionella contamination even when the thermostat  
is set for 60 degC (albeit according to studies done by the same Hydro  
Quebec that is promoting the use of 3 heating elements ).


If one draws one's water from a well or from municipal water supply pipes  
buried in the ground, the temperature of the incoming water temperature is  
likely to be somewhere between 7 & 13 degC (~ 45 & 55 degF).

Installing a few runs of large diameter pipe the length of the house  
somewhere in the conditioned interior (ie an empty joist bay) in order to  
temper the water before feeding into the DHWH would significantly reduce  
the temperature rise that the DHWH would need to provide. ie 21 degC to 60  
degC  instead of 7 degC to 60 degC.)

Expose that "tempering reservoir" to the sun and the temperature  
differential would be reduced even more.

Although Ottawa Hydro has provided all of its residential clients with  
Smart Meters

      http://www.hydroottawa.com/timeofuse/index.cfm?lang=e&template_id=356

.... I continue to use the timer that I installed in the circuit to the  
DHWH when I built my home almost 3 decades ago. I have always had it set  
to turn off the supply to the heater's elements for all but the few hours  
around the peak hot water demand times (early morning and supper time) and  
in all these years have yet to experience any shortage of hot water.  (And  
yes, all the plumbing supply lines (both hot and cold) were insulated ...  
around the cold water lines to prevent condensation during our humid  
summers).

-- 
=== * ===

Rob Tom
Kanata, Ontario, Canada



More information about the Greenbuilding mailing list