mini-split that heats to below 60F set points

[tff]

Building a garage and including a mini-split unit. My builder, who i believe uses Mitsubishi products, says that their units don't allow heating set points below 60F. I'd like the ability to heat the garage at lower settings, say 40F or 50F.

Can anyone recommend a quality unit that has lower heat set points?

Thanks.

 

[Milton Shaw]

I know GE PTAC units would turn on from a freeze sensor if the room temp got below 40 even is the unit was in the off position. I don't know if that option is available on the mini split units but suggest you check instruction manual and wiring diagrams to see if there is a freeze sentinal on the diagram. Or call tech support on that unit.. Just a though it may already have that low temp activation built in..

 

[PoorOwner]

You can use the Mitsubishi accessory MHK1 then you can choose as low as 50, maybe even 40s


Without it, you can also set it to 50 with smartset function on the remote, but it is either 50, or 61. The (50 is their freeze protection for vacation homes)

Some of the Daikin can set 50 thru 60+ out of the box. However minimum cooling is 65 vs Mitsubishi 61

 

[Grant F]

The gree virieo has what I believe they call freeze guard which is I believe 48 or 49. Like poorowner stated mitsubishi units have a similar setting although I am not sure that all models have it. When I was looking I remember some mistu models seemed to have it and some did not but maybe there was something I missed.

 

[soob]

Most generic mini splits have an anti-freeze mode you can enable somehow that sets the temperature at 40 or so. I don't remember how to do it, but it can be done. It might be called "vacation mode" or the like.

It is very annoying not being able to set the thermostat below 60, I agree. But mine seems to keep the temperature about 5 degrees below what it's set at, for some reason, but I'm not complaining.

 

[aardquark]

I have two Mitsubishi outdoor units, both with the MHK1 wireless thermostats. One is a single zone MUZGE24NA, and I can set the temperature down to 50 (that is the lowest it will go). The other is a tri-zone MXZ3C24NAHZ, and I cannot set it down lower than 60, (with the MHK1). But interestingly enough, on one of the heads attached to the tri-zone I have a different interface, the Kumo Cloud WiFi Adapter (PAC-WHS01WF-E), and using that I can reduce the set point to 50 degrees. (All temperature units are degrees Fahrenheit).

I have searched through the Mitsubishi manuals, and never found these limits mentioned,
but that is my experience. I found it curious that on the same unit, the different unit adapter allows me to go to the lower temp. My best guess is the 60 limit is what you can tell the head, and it will modulate to meet that, but the unit is turned off and on to get to the lower set point using the Kumo cloud interface. But that is just a guess, I have no evidence of that. It does work, however in that the room temperature is held around 50.

 

[PoorOwner]

I have two Mitsubishi outdoor units, both with the MHK1 wireless thermostats. One is a single zone MUZGE24NA, and I can set the temperature down to 50 (that is the lowest it will go). The other is a tri-zone MXZ3C24NAHZ, and I cannot set it down lower than 60, (with the MHK1). But interestingly enough, on one of the heads attached to the tri-zone I have a different interface, the Kumo Cloud WiFi Adapter (PAC-WHS01WF-E), and using that I can reduce the set point to 50 degrees. (All temperature units are degrees Fahrenheit).

I have searched through the Mitsubishi manuals, and never found these limits mentioned,
but that is my experience. I found it curious that on the same unit, the different unit adapter allows me to go to the lower temp. My best guess is the 60 limit is what you can tell the head, and it will modulate to meet that, but the unit is turned off and on to get to the lower set point using the Kumo cloud interface. But that is just a guess, I have no evidence of that. It does work, however in that the room temperature is held around 50.

check option

170 Max Heat Setpoint 90 90 °F (32 °C) * Subject to
40–89 40 to 89 °F (4.5 to 31.5 °C) HVAC Equipment

172 Min Cool Setpoint 50 50 °F (10 °C) * Subject to
51–99 51 to 99 °F (10.5 to 37 °C) HVAC Equipment



note, there isn't a minimum heating. I remember I can definitely set a scheduled heat setpoint to under 60 on my unit.

 

[walrus]

My fujitsu will go to 50

 

[gmoss]

Old thread, but just jad the system below installed. Lowest heat temp is 61. Doesn't seem to have a Smartset setting.

Thought I would ask if there is a way to get set at 50 or so, if anyone may know. Maybe an optional remote or Tstat.

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Did not buy from here, just same one.

 

[My Old Tools]

MrCool has the FP (freeze protect) setting which is 45 degrees.

 

[gmoss]

Did some more research last night, which may help someone else in the future. The MHK2 Tstat has the capability to go below the 61° threshold. My issue is ATM is no Wifi. Once I get that squared, will likely add that thermostat.

 

[maplewood]

MrCool has the FP (freeze protect) setting which is 45 degrees.

How do you turn that on? I've long lost the manual but would love to heat to "not freezing" instead of 60. Doesn't get cold often here, I just want my water-filled engines not to die for the few nights it dips below freezing.

 

[My Old Tools]

How do you turn that on? I've long lost the manual but would love to heat to "not freezing" instead of 60. Doesn't get cold often here, I just want my water-filled engines not to die for the few nights it dips below freezing.

In the phone app, it is a pull up on the heat page that says FP. On the remote it's a button that says FP.

 

[fitter30]

Manufacturers don't put a minimum temp on the thermostat for nothing. Freeze protection thermostat is for a emergency to try to keep the house from dropping further causing some real damage. If it shortens the compressor life to save the house its a small.price to pay. Refrigeration compressors are design for certain compression ratio. Controls and expansion valves are not working at design temps. Call the company that you bought the equipment from and what the btu output at 45°.

 

[gmoss]

If it was an issue, they would not offer a Tstat that goes to 50°, at least in my application. It may not be "best", but in a drafty shop, it will cost a lot more to keep a 60° mean than a 50° mean when not used, at least in winter. I will have time to see how it affects my power bill before worrying about the Tstat since I will have to purchase another Starlink router to widen the wifi band on my property.

 

[bobg03]

it's been ungodly cold here at the coast in the teens, I have the ability for Freeze Protection on mine at 42 degrees. As cold as it has been tho I just have left it running at 63 degrees overnight, my lowest set point is 62.

It's cheap enough to run at 63 and easily made warmer if need be.
Same thing w/the air when it's 110 out, I turn it on early and set it at 80 and it's perfectly comfortable for the day.

 

[My Old Tools]

Manufacturers don't put a minimum temp on the thermostat for nothing. Freeze protection thermostat is for a emergency to try to keep the house from dropping further causing some real damage. If it shortens the compressor life to save the house its a small.price to pay. Refrigeration compressors are design for certain compression ratio. Controls and expansion valves are not working at design temps. Call the company that you bought the equipment from and what the btu output at 45°.

There are absolutely no warnings of any kind about using Freeze Protect. It exists to simply keep a space far enough above freezing to keep pipes and such safe. It no different than running 65 degree heat when it's 62 outside. It works to a set point, nothing different about the compressor usage. Where did you get your supposed information?

 

[fitter30]

There are absolutely no warnings of any kind about using Freeze Protect. It exists to simply keep a space far enough above freezing to keep pipes and such safe. It no different than running 65 degree heat when it's 62 outside. It works to a set point, nothing different about the compressor usage. Where did you get your supposed information?

42 years of running commercial and industrial hvac service
Mitsubishi customer care 800 433 4822
If they can't help ask for tech

 

[My Old Tools]

42 years of running commercial and industrial hvac service
Mitsubishi customer care 800 433 4822
If they can't help ask for tech

This ain't Mitsubishi

 

[WildBill]

Mr.Cool also has a "Comfy" setting under "eSaver" that lets you set a range down to 40F. I have mine bounce between 45-55F when I'm not in the shop.

 

[pembol]

Manufacturers don't put a minimum temp on the thermostat for nothing. Freeze protection thermostat is for a emergency to try to keep the house from dropping further causing some real damage. If it shortens the compressor life to save the house its a small.price to pay. Refrigeration compressors are design for certain compression ratio. Controls and expansion valves are not working at design temps. Call the company that you bought the equipment from and what the btu output at 45°.

I guess I am not quite following - when I run my heat pump, the inside unit (the condenser?) is much warmer than ambient, because it is heating, and the compressor and associated coils are at outside temperature. The only time the condenser is at 45F or what ever the room temperature is is for the first few seconds when it starts, then it quickly warms up to 110F or so, I am not sure how that would hut anything?

 

[fitter30]

I guess I am not quite following - when I run my heat pump, the inside unit (the condenser?) is much warmer than ambient, because it is heating, and the compressor and associated coils are at outside temperature. The only time the condenser is at 45F or what ever the room temperature is is for the first few seconds when it starts, then it quickly warms up to 110F or so, I am not sure how that would hut anything?

Compressors are cooled by the return ( suction) refrigerant not so much by the air temperature. At 45° outside the unit with go into defrost to get rid of the frost that builds up between the fins and surface of coil. Inside at 45° theres 56 lbs difference in pressure standing between 45° / 60°. Minis have so many more controls for the refrigeration system because their variable refrigerant flow. Get out of the design range the compressor compression ratio and expansion valves will be out of design range. Looked at Mr Cool mini a hyper heat unit heating down to -13° using R 32 refrigerate spec is 33° inside. This is a new refrigerant and haven't seen any equipment using it yet.

 

[WI/MI Border]

I'm considering a Pioneer or Della 18K BTU system for a future garage/shop. According to their AI answer (which I will never get used to believing) they both have a minimum heating set point of 60F. That's too bad. I want to keep the shop at 50F when I'm not occupying the space. Anyone have other models with lower heat set points?

Edit update... Pioneer techy person just responded with this answer to "What is the freeze point setting?"

Our units have a temp setting range of 62 - 86°F.
They also a have a special "Freeze Protection"/Vacation Mode fixed setting of 46°F which is used to keep pipes from freezing.
To put it into FP mode, please set it to heat, configure it to 62F, and then double press the down arrow button on the handheld remote.

46F is pretty close to 50F. That might work for me. I'll have a backup masonry wood heater as well.

 

[gmoss]

I'm considering a Pioneer or Della 18K BTU system for a future garage/shop. According to their AI answer (which I will never get used to believing) they both have a minimum heating set point of 60F. That's too bad. I want to keep the shop at 50F when I'm not occupying the space. Anyone have other models with lower heat set points?

The Mitsu I got has an optional wireless Tstat that allows you to set it at 50°. MHK2 is the accessory part #. I have been pleased so far with mine. I am not running it all the time. Since it takes a lot longer to heat up from a 30° night, if I am going to be in the building the next day, I turn it on and let it run overnight. 60 may not end up being so bad. I have some time to figure that out (going into spring)