HVAC Heat Pump Question

[lostchild]

I hate heat pumps, house never seems warm, wish I had my natural gas forced-air furnace back.

 

[DCV]

Dual fuel: 1st stage elect. heat pump compressor, 2nd stage gas furnace.
1st stage runs until outdoor thermostat senses that the outdoor temperature is below a pre determined temp, then 1st stage cuts out and 2nd stage gas furnace takes over.
You can`t run both stages at once with a dual fuel system.

Electric heat pump system: 1st stage elect. heat pump compressor, 2nd stage electric strip heat.
1st stage runs until indoor thermostat continues to drop 1 or 2 degrees, then 1st stage continues to run and 2nd stage electric strips cut in to add supplemental heat.

If the system runs more than it is off on a cold day but keeps the home at the desired temp that`s ok.
The newer, higher efficiency systems tend to run longer to heat or cool. The motors are higher efficiency and it is cheaper to run the motors constantly rather than start and stop often. The same principle applies to gas mileage in your car, better gas mileage at a constant speed in highway driving vs. start and stopping in city traffic.

Most of the common sense rules people have in their head about how things work or should work don`t apply to the rules of HVAC equipment.

 

[Boogar Presley]

I've found that keeping my ceiling fans on helps to circulate the air evenly throughout the house and use my heat pump less. I keep a small 500w heater on in the dogs warm so it's always toasty in there for them

 

[davans]

At 26 degrees outside early this morning, all three of my heat pumps were still putting out 90+ degree warm air. One unit (12 SEER) is 12 years old, the second one is also 12 years old (12 SEER) that had a new A coil (evaporator coil) installed in 2016, and the third unit (16+ SEER) is less than 2 years old, All three units still cycle but the new unit (16+ SEER) runs more than the older ones. However, on a positive note, it seems like the new unit can run all day with no meaningful impact on the electricity bill. For my 37 year old, 6,000 sq. ft. house, keeping the thermostats on 71 during the day and 68 at night, I am running at a $6.70 average daily cost in my current bill (not too bad, in my opinion). The only time the heat strips kick on are when I bump the t-stat up more than 3 degrees, which is a user-configurable setting in the programmable thermostats, and rarely, if ever, happens. Some units have heat pump lockouts based on the sensed outside temperature but that idea was "old school" thinking, especially with the newer, higher efficiency units.
View attachment 6594876

I would think at 26 degrees that the heat strips would be on, especially if you are getting 90 degree + temps.

 

[davans]

Dual fuel: 1st stage elect. heat pump compressor, 2nd stage gas furnace.
1st stage runs until outdoor thermostat senses that the outdoor temperature is below a pre determined temp, then 1st stage cuts out and 2nd stage gas furnace takes over.
You can`t run both stages at once with a dual fuel system.

Electric heat pump system: 1st stage elect. heat pump compressor, 2nd stage electric strip heat.
1st stage runs until indoor thermostat continues to drop 1 or 2 degrees, then 1st stage continues to runs and 2nd stage electric strips cut in to add supplemental heat.

If the system runs more than it is off on a cold day but keeps the home at the desired temp that`s ok.
The newer, higher efficiency systems tend to run longer to heat or cool. The motors are higher efficiency and it is cheaper to run the motors constantly rather than start and stop often. The same principle applies to gas mileage in your car, better gas mileage at a constant speed in highway driving vs. start and stopping in city traffic.

Most of the common sense rules of people have in their head about how things work or should work don`t apply to the rules of HVAC equipment.

Sounds like you know what you are talking about. I know my other homes with dual fuel switched to gas at a certain outside temperature. I’m just not use to it running so much.
Thanks for your input.

 

[Rougarou]

I would mostly question your home, insulation in the attic, insulation in the walls wall insulation deteriorates over time and starts compacting down and can leave over a foot of non insulated wall at the top, floor insulation if on a slab seal plate leaking air, also air infiltration seals around the casing of windows, wall sockets on exterior walls, any penetrations in the ceiling wires ran down walls, ceiling lights, ceiling fans, attic stairs are a biggie, there is a ton more to keeping your house comfortable other than the HVAC system, as far as heat strips in a standard heat pump they rely on the thermostat to tell them to come on or the outdoor system will turn them on during defrost cycle. My heat pump thermostat is wired so after about 10-20 minutes of heat running it kicks the strips on also.

 

[MegaFan]

I would think at 26 degrees that the heat strips would be on, especially if you are getting 90 degree + temps.

Not at all. My three units are serviced annually and they provide "warm" air down to 20 degrees and lower. When the heat strips cut on, you can smell the dust heating and see the "emergency heat" indication on the thermostats. Typically, only happens after traveling, where the t'stats were set to 65 or lower, then trying to warm up quickly when we return.

 

[roundhouse]

The unit is programmable , you can tell it when to kick on the strip heat

I have a new 14 SEER heat pump and the strip heat comes on below 20 , —IF— the heat pump had been running for more than an hour and the house is still more than 3 degrees below the set point .

The strip heat is very expensive .
You don’t want it running .

 

[thevalueman]

My strips don't usually come on until the outside temp is below 15....now, the pumps run constantly....so, I guess that's a good thing...I'm sure the wear doesn't cut down on the life span of the unit....right???

 

[Mr. Goodbar]

Do mini splits have heat strips, just saying, I don’t know nothing