Re: Hot water heater for hydronic heat
Posted by More on November 19, 2001 at 23:19:52:
In response to Re: Hot water heater for hydronic heat
You can use the hot water heater to provide the heat, but the pressure will be the same as the rest of the house in the heated piping, unless you install a pressure reducer. The hot water heater will cook the water to about 105 degrees, send it to your attic, and then what will you install radiators? or simply use coils in the floor or on the walls? If you use plastic, you have the concern of the pipe body expanding and contracting at a different temperature than the fittings, and cracking the pipe glue at the joints. Also the plastic will lose most of the heat to the outside room cooler air in a very short run, and will cause the water heater to cycle eight times more often. Copper runs, fittings and sweat joints, will give a better installation, but you still have the temperature coefficient problem. The water heater is designed purposely not to get hot enough to cause great bodily scalding, and therefore is a poor choice for a radiator heater supply. Radiator boilers cook the water to above boiling point 212 degrees for this very reason, and then the radiators require a condensate return line back to the boiler. Consider an oil filler electrically warmed radiator for the attic.

: I want to use my hot water heater to provide heat for our finished attic.
: Our home is forced air but ultimately I will convert to hydronic.
: Any concerns?
: Can I use plastic pipe for the runs? I can sweat copper no problem, just wondering.

: Thanks and God bless you. Charles

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