I have a few basic questions about the 850's AC system.

1. I have heard that running a car's air conditioning system with cold outside temperatures can cause the compressor to fail since it will suck up liquid refrigerant due to the fact the refrigerant didn't fully evaporate in the evaporator. Is this a real danger?

2. I remember that the same person who mentioned the issue in question #1 also said that most cars have a sensor that will turn off the AC if the car senses an outside temperature that is too low. Does my 850 have one of these?

3. Does air flow through the heater core before or after passing through the evaporator in Volvo 850s? (I ask this because I would think running the heater could solve the issue I asked about in question #1 (refrigerant not fully evaporating) assuming air flows through the heater core before it flows through the evaporator.)


TI ask these questions because I have been told it is good to run the AC occasionally throughout winter to keep the seals oiled and in shape, preventing leaks, which I can understand. Additionally, I want to use my AC for defogging, but I am reluctant to run my AC when it really cold outside for I fear I will damage my compressor. Will my car prevent this from happening, or should I avoid running the AC in winter altogether?

Thanks in advance!

1995Volvo850

 

I beleive your A/C will not operate below 32 deg F. It is best to leave the A/C "ON" all the time. Notice the switch is either in AUT or OFF, and when you turn it to OFF, the light turns red/orange.
I say leave it in AUT. That is what I do and haven't had any issues.

 

#3, Air runs through the evaporatir before it goes through the heater core. As noted, leave the system on, it will take care of itself. It usually runs anytime you select defrost/defog, it really helps clear the windows of moisture.

 

 

I have the manual climate control, so I can't leave the AC on auto. If I turn the switch on, the AC runs endlessly until I tell it to turn off, so I don't really want to be wasting all that power on it 24/7. I do want to use it for occasional defogging and dehumidifying, though.


Even so, should I still be OK running it in cold temperatures? I hope it will automatically shut off before the compressor damages itself.

 

Turn it on whenever you like. I repeat... The system will protect itself.

 

Cool. That's what I wanted to hear!

Thanks.

 

Since I work in the HVAC industry I like to run the equipment I work on a little in the off season and I do the same with my car and I run the AC about once a week for 5 minutes or so just to keep seals and stuff lubed and under pressure. It can be expensive and time consuming to replace dried out seals. There is no reason to run the AC all the time.

 

I'm not familiar with the manual system but if you can turn the AC on when you have it in defrost. You will notice a vast improvement in defrosting with the AC on (temp all the way to hot).