question about ac wall unit used in winter when outside < 32°

ron

have a carrier 2 ton unit, ductless, operated by remote control only.
have the thing turned on, it's blowing air, and it's commanded to be cooling because the remote has the little snowflake displayed. buy i'm not getting any cooler air than what's in the room from the wall unit, and this is when the room has been 80-85° and I'm telling it cool to 70°.
my question is, because it's winter and and it may be 35°, 25°, or even 5° outside, will that outside temperature prevent the outside condenser unit from kicking on?
Does anyone know of AC units, that if it's very cold outside that the outside unit definitely would not turn on?
Or if the cold outside temperature would cause some other problem preventing the inside wall unit from cooling?
thanks.

JUGHNE

You might be lucky that it will not run @35.

Can you just open a window to cool the room down?

It takes some special AC components to cool at that cold.
Most will eventually die if forced to run at that cold.
Does your unit have a "fresh air" inlet opening? That would just bring in outside air with fan only operation.

John Mills_5

Need to check the minimum operating ambient of that exact model. Some will shut down when it hits that point. Many have options for low temps, 14 or 0. We have a customer that has a Sanyo and at -4 it is off. Comes back on at 0. One new model Carrier cooling only that I looked at runs to 14 out. The manual didn't say what happens below that.

ron

it's a room within center of building, no windows, bunch of computers as the heat load. existing hvac system has problems and this ductless wall unit installed as supplemental cooling.

you said: "Most will eventually die if forced to run at that cold".

1) am i correct in assuming once it's however cold outside, say 35°F or less then the outside unit to this ductless system would not go on... because it senses outside temperature being that cold and has been designed to only operate when outside temperature is above a certain value?

2) or if the outside unit does not sense outside temperature, then should it always operate if i command the wall unit to cooling mode with the remote? If so, are you then saying because it's so cold out that I am then running the system outside it's designed environmental operating temperature and there's a good chance the system is now broken?

i have to find the model number and book on this thing,
but wanted to know if there was a good chance this thing was installed with impractical expectations. I know enough about hvac and refrigeration to be dangerous, but not general operating conditions and limits of various ac systems... i never gave it any thought about operating an air conditioning system in winter. I know on my truck its ac will work down to around 40°F for defogging the window, but on 20°F days the snowflake will blink on the display then go out and i know the compressor does not engage, all of which i assume there is a reason for but don't know specifically & technically why.

ratio

Most (all?) systems can be fitted with low ambient controls, a Carrier mini split low ambient kit might be as simple as a fan cycling switch and a wind baffle. Google the model number & see what's available from the factory.

We often install mini splits in IT rooms & data closets. It's way cheaper than doing it the right way, and they perform adequately most of the time.

JUGHNE

I was thinking you had a thru the wall unit AC or PTAC.
You need a CCH and some form of head pressure control...maybe the fan cycling control......variable speed fan control. The best would be a "Headmaster" control, but that is usually a factory install.

Your mini split AC probably locked out with a LACO T-stat, to save the compressor.........keep the power on to the unit as it may have a CCH already.

Your truck AC is designed to run at low temp for defrosting.

Mike

Most min split systems have a low ambient limit. Carrier depending on the model, can be anywhere from 28 to 5 degrees. If it's their newer inverter model, it can be down to 0, with the wind baffles. It could be the senser is bad. Call tech support, they will help.

Paul S_3

Is this a fairly new unit...is this a heat pump...Whats the model number.....the carrier infinity mini splits can cool from 0 F to 129 F......this is the GRQ series...some cooling only carrier ductless have a minimum operating temp of 55f.....where are you located im a Factory authorized Carrier dealer in NYC.

ron

it was new within last 2 years.
outdoor unit is carrier 38HDF036- ?
inside wall unit is 40QNC036-3-01, told it was a 3-ton unit.

Paul S_3

The Carrier 38HDF's will NOT operate below 55F....it is not made for a server room....it is a 3 ton unit

ron

thanks for the help,
i also found 40QNC-Q-11SI.pdf and 40KMC-Q-1PD.pdf online for the unit where it describes that.
figures.