Mitsubisi hyper-heat cold weather performance results

I had a Mitsubishi hyper-heat mini-split unit installed Q4/2015 in my garage. Because of the mild temperatures in my part of the country, it has not gotten cold enough until recently, to see how well the heating function of this unit worked.

Last night the reported low temperature was ~27F. I have my T-stat set at 50F, below is a pic of the temperature monitor I have in the garage, seems the little Mitsu is doing its job. Monday night the temps are supposed to drop into the low teens (10-12F) I will post up the results after that.

Just thought that those of you considering this unit might be interested in seeing real-world performance. FYI- my garage is ~800ft2 and walls and attic space is insulated. Although the garage doors are not well insulated, basically builder quality units.

27 degrees is right in its wheelhouse, I'd say 10 degrees won't bother it either although the efficiency will drop some and the total amount of BTUs it can produce will go down also. Heating to 50 will be easy for most modern mini splits assuming correct sizing of unit. What will be interesting is what your electric bill does.

walrus said:

27 degrees is right in its wheelhouse, I'd say 10 degrees won't bother it either although the efficiency will drop some and the total amount of BTUs it can produce will go down also. Heating to 50 will be easy for most modern mini splits assuming correct sizing of unit. What will be interesting is what your electric bill does.

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still kicking **** at 10 degree's

start to lose it's edge below 0

Now if someone can explain what "hyper heat" is (possibly just a marketing term) ...

theoldwizard1 said:

Now if someone can explain what "hyper heat" is (possibly just a marketing term) ...

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YeAh, a marketing term, but basically referring to units that put out heat Down to the -20F range without strip heaters.

Mine still provided not just warm but hot heat down to -15F last winter. Kept room temp at 73F which was set point.

fastjohnny said:

Mine still provided not just warm but hot heat down to -15F last winter. Kept room temp at 73F which was set point.

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next time that happens go outside and feel the insanely cold exhaust

Just kinda neat to be outside in such cold temps, and feel the south pole being expelled from the unit.

Last night the temps got down to 8*F. The Mistu unit maintained a steady 50*F in the garage during the entire time.

I will see if I can determine the electrical cost of this unit by looking at the utility bill alone. Since these units don't use heat tape or other external electrical warming devices, I don't expect a huge jump in electricity cost, as I would expect if I was using an electric heater

It is 7 F here and I left my Mitsu set at 66 and that's what it is this morning. The garage is well insulated but I still didn't expect the mini-split to keep up at 7 degrees despite the marketing hype.

I'm happy and warm.

Update on my unit, now that it's getting pretty snappy cold day/night...

I'm not sure what mode allows me to select the temp setpoint of 50*F, but when it gets in the teens outside, that mode dips a bit with respect to temp control. In the 20's and 30's the garage has always been a pretty steady at 50*F. When the temps drop into the low teens and single digits, I see the temp control band drop a bit too, from 50/52 to 48/50.

For grins, I wanted to see if this change in temp control was from lack of BTUs or simply just the control 'mode' that allowed me to set a control SP of 50* (seems that not all folks can set a SP below 60*).

It was about 12* today when I changed the temp setpoint to 65* to see how the unit would respond. In about 2 hours the garage (~750-800ft2) warmed from 48* to 58*, so the lack of temp control wasn't a result of the capability of the unit, rather something in the 'mode' that I had selected for it.

I was rather surprised to feel pretty warm air coming out of the head unit when I knew the outside temp was crisp 12*F. The air blowing from the external unit was pretty chilly...

I had a post a could of days ago. I installed a three head hyper heat system and also a VS Infinity Carrier HP ... They are amazing. The hyper heat refers to the reserve capacity of the uint that allow for very cold operation at full output.

It was 15 last night and the house is 74 -- Carrier unit was running at 2nd stage out of 5 when I checked in the middle of the night.