Vic Smith wrote:
On Wed, 28 Jan 2015 08:15:18 +0000 (UTC), gregz
wrote:



If a boiler is being used, then flue gas is over 200 degrees. My forced air
fan on 70k btu runs 300 watts or less. Maybe a bit more in air conditioning
mode. It's variable speed.

Greg

Flue temps on high-effeciency boilers run 125-135F according to what
I've read.

I don't see how that's possible, unless an extra ambient air heat exchanger
is used. I never measured a system. If incoming water is heated by another
pre exchanger with output of main exchanger, the flue gas will be closer to
incoming water temp.

Greg