heat pump with gas furnace

[Dan]

I live in Ohio. I have a duel-fuel system, heat-pump and gas furnace. I want to know how to get the best energy-efficiency out of the system.

Do I turn off the heat pump and only use gas furnace when the temperature falls below a certain degree? Is is best to leave the thermostat at a constant temperature or should I buy a programmable thermostat to turn down the heat at night? Are there any specific ways

to use the system for the best performance? I have heard many differing opinions and just need some clarification.

Thanks, Dan

[Oscar_Lives]

Set the thermostat where you want it, and don't f*ck with it. Only set it back when you are going to be away for more than a day or two.

[daytona]

That is what the Yuppies now call a hybrid unit. The saving for your area are only in the fall and spring....winter brings the secondary heat on a majority of the time.Some of the newer digital t-stats have the ability to shut down the ht pump and only run the secondary heat at a set temp (consumers choice)

[Oscar_Lives]

Why would you shut down the heat pump?

[Nathan In Montana]

im sorry (my wife is from ohio, and having been there myself its the only thing that comes to mind ;-)

let your t-stat control it.

doesnt your t-stat manage that via remote outdoor sensor? if it doesnt, get one that does. honeywell makes a nice touch screen programmable, but i dont have the part number handy.

i dont use a programmable t-stat. when its to cold i turn the heat up, when its to hot i turn on the a/c. for the most part i leave my honeywell set on auto, with the heat set to come on at 72 and the a/c to come on at 75. in general i set it and forget it. why would you turn down the heat at night.....isnt that when youre typically home?

[Nathan In Montana]

.....you ever been to ohio in the winter? :-)

[Bubba]

[Nathan In Montana]

at which point the efficiency is lost thus defeating its own purpose. i suppose you could run both, but to me it seems pointless.

[Noon-Air]

You *DO NOT* want to run both the heat pump and gas furnace at the same time. You run the heat pump down to about 35 degrees, then heat pump is taken out of the loop, and the furnace comes on line.

Think about *WHY* you don't want both to run at the same time......

(HINT Think "head pressure")

[Bubba]

35 degrees is too generalized. I had a heat pump today on a "tune-em-up". Outdoor thermostat was shutting the heat pump off at 35 degrees. That was the temperature today so the heat pump wouldnt run. I turned the stat down to 25 degrees. Went in and watched the heat pump run. I had 98 degrees just out of the plenum. I'll run em down to 25 degrees outside anyday. Bubba

[Nathan In Montana]

as i said above, i wouldnt run both.......but ive seen it done by folks supposedly smarter than me.

personally i wouldnt run it down that far, but im not anal about trying to squeeze every possible btu out of a penny. id rather be comfortable, and prefer to run a furnace at 40 or below. still, ive seen some that run the heat pump down to around 20 degrees.

again see my initial response above, i wouldnt ever recommend running both......just that ive seen it done.

[Mark]

agreed, especially when at or below 32 and the heat pump has to run in reverse to thaw out the outdoor coil...then it is time to shut it off and use the gas...

Mark

[daytona]

I never liked the engineers reason for leaving it on. The wattage usage to the BTU gain...and then they get the slide rule out while smoking their pipe..... not enough for me to leave it on....bring on the fossil fuel