[Greenbuilding] Max Temp Storage Water

[nick pine]

Lawrence Lile <LLile at projsolco.com> writes:

> Haudy sez:  There will still be a minor savings from turning off the 
> heater overnight...

> Yep, this is definitely minor, if your water heater cools off from 
> 120 to 115F and your house is 70F, then your losses go down 10% from 
> the standby loss...

If the standby loss is constant at 120 F for 12 hours and then drops 
to to 90% of that at 115 after 12 more hours, the savings is only 
2.5%, right?

But a 50 gallon water heater that supplies 40K Btu/day with a 0.95 EF 
would only cool to 120-0.05x40K/(50x8.33)x12h/24h = 117.6, with a 1.2% 
savings..

Nick