wrote
Rod Speed wrote
wrote
Most of the advice is to set the temperature to
140 if you have a dishwasher, 120 otherwise.
Those that know anything about Legionella dont.
http://www.ihf.ie/news/innsight/98-1...tm#anchor23477
Let's go back to Australia:
No thanks, that specification of the minimum temperature
that storage hot water heaters should be set to is just
about universal right thruout the first world now.
Because Legionella is a real problem with showers.
http://www.safetyline.wa.gov.au/page...dewswa0210.htm
"Long exposure at 50C or shorter exposure at higher temperatures
is sufficient to kill the bacteria." That would be 122F.
Thats on the low side of the recommendations,
60C, 140F is much more common.
http://www.google.com.au/search?q=Legionella+60+C
I remember The American Legion meeting, but that was
warm water in a cooling tower, not a domestic water heater.
Sure, and after that it was realised that storage
hot water services could be a real problem with
Legionella when they are set a lower temperatures
to avoid scalds with kids and the elderly etc.
Presumably we didnt see that much of problem with
Legionella in storage hot water systems because
most didnt deliberately turn back the setpoint much
before that American Legion meeting made it clear
what a problem that particular bacteria could be.
"Proliferation of L. pneumophila is promoted by:
a wet warm environment (range 25-42C);
optimum temperature (35-37C);
stagnation or low water turnover;
high microbial concentration including algae, amoebae, slime and other
bacteria;
presence of biofilm, scale, sediment, sludge, corrosion products or
organic matter;
presence of certain materials such as natural rubber fittings which
may be a nutrient source. "
Thats just cooling towers, different animal
entirely to storage hot water services.
I don't think that describes my domestic water supply.
See above.
The recommendation for 120F still stands.
No it doesnt if you actually have a clue about Legionella
That won't scald, and it will kill Legionella bacteria.
Have fun explaining the common code requirement of 60C, 140F
http://www.dhmh.state.md.us/html/legionella.htm
says you are just plain wrong using rigorous science.