Stupid question of the day, do I turn off A/C in winter

[Anijake]

I have the GT w/tech and have the climate control on and set to 72. During the winter should I hit the A/C button to turn it off or does the climate control need it to stabilize the temp?

 

[Buddyb]

The A/C is normally used to cool outside air but It does do more.

A/C dries out humid air which will usually wipe out windshield fog. Use A/C when you want to change the outside air quality.

 

[Maineiac]

^^^ Exactly right, you will need it to dehumidify the windows.

 

[erhayes]

The AC will not dehumidify if you leave it on 72 and the outside air is 20 F. On my CX5 I would need to manually switch it on. Ed

 

[GAR]

A/C use in winter

I have the GT w/tech and have the climate control on and set to 72. During the winter should I hit the A/C button to turn it off or does the climate control need it to stabilize the temp?

Being a native Floridian and longtime operator and chief technician of an automotive A/C repair shop , I can say I use my A/C every month of the year to some extent , but as said here it is used along with defroster to remove humidity.
Also though , it is good practice to run the A/C occasionally even in winter months to maintain the system.
The refrigerant is circulated through the system and through the receiver drier to remove internal moisture and also to lubricate the seals.Both of which will help prevent leaks (a leaking seal can allow moisture in system which in turn becomes acidic and begins to attack internal components , especially aluminum , i.e. evaporator ,condenser ,etc. ) In addition low refrigerant can cause premature compressor failure due to oil starvation ( No oil sumps on compressors anymore , is blended with freon for circulation ) , as well as clutch wear and failure due to excessive cycling. People can't understand why A/C repairs are so costly but something very simple can quickly become catastrophic.

Be safe and just run it once a week or so even if you don,t feel you need it.

 

[CC58]

Cars from about 1990 on will automatically turn on the AC for short periods during the winter. The fan is not necessary as all it is doing is circulating refrigerant and exercising compressor briefly. They do this so to insure it will work the following spring. I'm sure the CX-5 does this too.

 

[Bcdad182]

Not sure about US models, but Canadian models will turn on the AC automatically when one of the defrost modes is used. This helps to dry out the air and defog the windows faster...and it works great in rain, damp, cool climates. So unless you never use defrost mode, your AC will be on frequently. Also, most modern cars will cycle it on some sort of schedule to keep it lubricated etc. Generally a few seconds each start, so I don't think you need to cycle the AC manually like in older vehicles.

 

[Capsfan84]

Not sure about US models, but Canadian models will turn on the AC automatically when one of the defrost modes is used. This helps to dry out the air and defog the windows faster...and it works great in rain, damp, cool climates. So unless you never use defrost mode, your AC will be on frequently. Also, most modern cars will cycle it on some sort of schedule to keep it lubricated etc. Generally a few seconds each start, so I don't think you need to cycle the AC manually like in older vehicles.

Does this apply (to the US or Canadian models) even when the A/C light is off? There are times when I will turn on the defroster with the temperature setting at cold and the air coming out of the vents feels very cold assuming that the A/C is off. I'm guessing that they A/C is turned on regardless of whether or not the light is on.

 

[Beefy]

I'm guessing that they A/C is turned on regardless of whether or not the light is on.

Yep, RTM. Canadian 2014 CX-5 manual has it on page 5-6: http://www.mazda.ca/MciWeb/pdf/manuals/2014/2014_CX5_8DB5-EA-13H_Edition1_E.pdf

 

[Kedis82ZE8]

I know it defaults to AC with Defrost position but it would appear this could still be overridden with switch. I'll see if FSM shows anything conclusive.

 

[Capsfan84]

Yep, RTM. Canadian 2014 CX-5 manual has it on page 5-6: http://www.mazda.ca/MciWeb/pdf/manuals/2014/2014_CX5_8DB5-EA-13H_Edition1_E.pdf

Yes but that refers to the Canadian model, I'm interested in the US version if there is in fact a difference.

Edit: And in checking the US manual I see it's the same deal, doesn't look like it can be overridden.

 

[Bcdad182]

Does this apply (to the US or Canadian models) even when the A/C light is off? There are times when I will turn on the defroster with the temperature setting at cold and the air coming out of the vents feels very cold assuming that the A/C is off. I'm guessing that they A/C is turned on regardless of whether or not the light is on.

The AC comes on in the defrost mode and the indicator does not light up. You can tell as the air gets really cold. There's actually a warning in the manual to not use defrost with the temperature set to cold as it can frost up the outside of the window (I suspect only if it was cold out). I always turn the heat up to compensate for the A/C

For what its worth, my wife's 2005 Honda does the same thing when set to defrost.

The owners manual does say to run the A/C for at least 10 minutes once a month to keep things lubricated. I would assume that running in defrost would also count towards this.