heatpump question? please help.

[kurtflys]

Can you run a heatpump the same time as fossilfuel ? . or will you burnup the compressor. please elaborate.

[ISOTHERMAL]

Wrong forum, this is the convention forum. But to answer your question. Do not run both at the same time. You will be putting hot air over the indoor coil.

[clintkennon]

That would just be silly. Not recommended and your system shouldn't operate that way if it is. Burning up the compressor? Maybe, possibility. this will lead to very high head pressure and could cause compressor failer. But compressors can and do take allot of abuse. so if it runs like that for a short time it probably will not kill the compressor.

[mgould2]

We install them often. Your installer should install a fossil fuel kit or a thermostat that turns off the heat pump before starting the Furnace.

This is over simplified, but you get the Idea of how this works.:cool:

[Milk man]

We install them often. Your installer should install a fossil fuel kit or a thermostat that turns off the heat pump before starting the heat pump.

This is over simplified, but you get the Idea of how this works.:cool:

:)That's a neat trick, turn off the HP before starting the HP. Well I guess you have to turn off something before you turn it on. ;)

[Milk man]

Yes a heat pump can run at the same time as the furnace. It is actually an option in some duel fuel stats.







Okay, before you all jump me. Some stats will leave the HP running while the HX is warming up. Then shut it off.

I alway turn that option off.

[beenthere]

:)That's a neat trick, turn off the HP before starting the HP. Well I guess you have to turn off something before you turn it on. ;)
LOL...

Except during defrost cycle, it is a bad idea to have the furnace and HP run at the same time.
If the furnace was running at the same time, and the HP doesn't have safeties to shut it down, the compressor would start to overheat.

[kurtflys]

thanks guys, just need to prove my point at work.

[beenthere]

Easy way.
Is just to relate it to how the head pressure increases in summer as the outdoor temp increases.
If a R22 system runs at 225 PSIG when its 95 outside. Think how much higher the pressure will get when its in heat mode with 13° air entering the smaller indoor coil.