Question for mini-split heat pump users

[46MGTC]

Got a question for those who have a mini-split heat pump in their garage.
How low can you set the temperature? I bought a cheapy heat pump on the internet that works great for both heating and cooling. Just started to need heat and, unfortunately, I realized that I can only set the minimum temp to 62F. I was hoping to be able to keep the garage at 50ish when I'm not there for several days at a time.

There is no separate thermostat, just the remote control and the indoor unit control panel. It's a 17 SEER inverter heat pump so it may turn out to be not that bad electric wise but still seems a waste.

It's my fault for not checking before buying but I never thought about it in the middle of July.

How are other users finding this?

Thanks,

Dave

 

[MikeLawrence]

The ones I'm familiar with have a "freeze-guard" setting (not a temperature setting, like a special setting) where they will automatically keep a room above 45 to prevent freezing related issues but if that one doesn't have that then it doesn't have it.

Worst case figure your heat pump is keeping it 60 (considerably) cheaper than a resistance would keep it 50 and write it off as it being the way it is.

=\

Michael Lawrence, Lissco

EDIT: "I've heard" a thermistor works on the principle that its resistance varies with temperature. I bet if that thermistor were a positive one and it were to resist a little more current than it expects then perhaps it would read the room at 65 when it was really at 55... I'm certainly not advocating something like this but if I were to try something like it I'd be sure to have a switch setup (and use a multimeter to find the exact resistance necessary) so I could bypass the resistor come spring.

 

[trythis]

Unless the thermostat is hard wired into it, you just need to find a heat pump thermostat that goes lower. You could also pop a switch in the thermostat that redirects the heat demand setting to a separate heat only thermostat that has a lower setting capability.

 

[Track t-4]

I'm curious, why do they limit the unit to this temperature?

 

[cowboyjosh]

I'm curious, why do they limit the unit to this temperature?

From what I have been told, to keep from fu*king up the compressor, some manufacturers have units that go to a lower temp, but as far as I know every heat pump had a thermistor that cuts off at some point. On a household type heat pump, when the thermistor reaches its cut off, its usually when the "emergency" heating element kicks in. On mini splits, I reckon the thermistor is in the outside unit, and there is really no way to over ride this self protecting feature.

 

[MikeLawrence]

From what I have been told, to keep from fu*king up the compressor, some manufacturers have units that go to a lower temp, but as far as I know every heat pump had a thermistor that cuts off at some point. On a household type heat pump, when the thermistor reaches its cut off, its usually when the "emergency" heating element kicks in. On mini splits, I reckon the thermistor is in the outside unit, and there is really no way to over ride this self protecting feature.

You're talking about a different T-stat. The one he's interested in is the indoor which he just wants to be set cooler than 60 which would never hurt anything.

On many heat pumps there is a thermistor on the outside which will prevent them operating at subzero like you are saying, but that's something else entirely.

 

[cw_racefan]

I have a cheapy mini-split also, and mine only goes down to 61 as well. Count me in as another one that wanted to be able to keep it at like 45-50 but can't. I wish it had a freeze guard setting but it doesn't, and yes, the thermostat is built in.

 

[46MGTC]

Thanks for all the input so far. Sounds like all the "internet special" units are basically the same. Mine doesn't have a freeze guard either. It's a pretty basic unit. Gets what you pay for, I guess. It isn't a Mr. Slim but it costs about a third too.

I guess I'll need to get a month or two of bills to see what this thing is costing me. If it really runs up the bill maybe I'll try to fool the thing with a small lamp just below the control panel.

 

[Rosco]

For those of us who are still in the process of researching mini-splits, do you mind naming the ones you bought?

 

[cw_racefan]

Mines a "Bonair" or something like that. They were around on ebay for several years, but are gone now. Looks very similar to alot of the "off" brand names, down to identical remotes.

 

[46MGTC]

Hello, my name is Dave and I bought an Ambiance ECO Green

http://www.minisplitsystems.com/cgi/display.cgi?item_num=18WHRDC2

Actually works pretty well but very basic control.