How does a mini-split perform for heat in cold climates?

[trainer]

I'm planning a 20x45 addition to a building. Three new walls against an existing building with just a single door betweeen the old and new parts.

The main building is currently heated by reclaimed heat, but there isnt enough to heat the addition. The only utility to the building is currently electricity.

Would a mini-split in heat pump mode work very well in a climate where averge january temp is +10°f?

 

[ghnl]

Generally, their efficiency drops off below 20F to 30F. Some units have heat strips built in so that during very cold weather they are basically electric heaters.

 

[sneezer41]

The new Mitsu units will preform when it is quite a bit below zero

 

[oldgoat]

Generally around here the heat pumps aren't very well favored. When it gets down in the 20 degree range and lower you basically end up with a electric heater. I've heard some claim good results, but way more often than not I've heard more negative.

 

[Scout Driver]

Here in northern South Dakota, a heat pump will be pretty efficient down to about 30 degrees. Below that level, they will function on whatever you are using for "backup heat", either the electric or propane heat unit in the heat pump. At ten degrees F, your heat pump will be well out of its efficient range.

Depending on your average temp range over a year, a heat-pump may still be efficient enough to be worthwhile. My house is about 1200 square feet. Setting the thermostat to 68 degrees, my highest heat bill will be 120 per month during a very cold month (10 degrees to well below zero). Get back to temps 30 or above and the heat bill drops to around 40 bucks. A/C set to 74 degrees will run about 8 or 9 bucks a month! My average heat and A/C bill is pretty reasonable.

Hope my ramblings can be beneficial to your decision.

Scott

 

[trainer]

Thanks for the responses.
Looks like I'll be better just to put in an electric unit heater, because we really dont need a/c.
I was just looking around online and the price of a split unit isnt really much more than a decent electric heater, plus I will have a refrigeration tech on site for some other work.

 

[SmokeyDP]

The mini-splits all claim they work down to 12F and I have found people who said they used them when their primary heat when out at those temps. But I wouldn't plan on using it for an extended time.