[Greenbuilding] Flatten the Curve

Paul Eldridge paul.eldridge at ns.sympatico.ca
Sat Aug 20 20:56:33 CDT 2011


My apologizes folks, Thunderbird is configured to automatically covert 
all list messages to plain text, but something seems to be tripping me 
up. I appreciate your patience as I try to get this resolved.

Hi Reuben,

Our tank is 70-litres in size which seems more than adequate for our 
modest needs.

For a good overview on the risks of legionella as it pertains to 
electric water heaters, see: 
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2094925/

According to Hydro Quebec, "[e]ven at 60 °C – the setting on most 
electric water heaters – an estimated 25% of all water heaters are 
contaminated by legionella bacteria." They go on to say that "[i]n 
Québec, about 100 people a year are hospitalized for pneumonia caused by 
contaminated residential water heaters”. (source: 
http://www.hydroquebec.com/advice_hot_water/index.html) I figure a dial 
setting of 75°C, knowing that the temperature at the bottom of the tank 
will be several degrees cooler, provides us with some greater measure of 
safety and this, at least to my mind, justifies the additional standby 
losses.

Cheers,
Paul

 >You think? Um, any particular reason for going that high?
 >What is the size of your storage tank? At 170F I'd think you could get by
 >with about 5 or may 10 gallons of storage.
 >
 >If at 170F you think you are but *minimizing *risk of legionella, what 
must
 >the 99.3% rest of us with storage water heaters at lower thermostatic
 >setpoints be?





More information about the Greenbuilding mailing list