A/C question,

grasmere59 · Post by **grasmere59** » Sun Jan 30, 2011 4:38 pm

Is there an outside temp when the A/C won't operate? I tried mine today just to give it a run and it would not come on.

Gary406 · Post by **Gary406** » Sun Jan 30, 2011 8:35 pm

air con shoulod work at any temp cos i use mine on hot, demists the windows faster

i think once the light stops coming on , on the switch, it may need re-gassing ?

mine certainly works even at -10

Post by **steve_earwig** » Sun Jan 30, 2011 9:12 pm

I think... no, hold on...

Welly wrote:...the a/c will not run below 0deg C ambient - this is to protect the compressor.

Gary406 · Post by **Gary406** » Mon Jan 31, 2011 8:01 am

weird. mine certainly runs well below 0

well the light comes on on the switch so im presuming its on

Post by **Welly** » Mon Jan 31, 2011 8:06 am

All modern-ish cars have a low temp cut off but some vary between -5deg, 0deg, +2 deg etc etc.. it's because the refrigerant oil cannot vaporise and circulate at these low temps so can damage the compressor. You don't really need the a/c function at these low temps as the outside air is very 'dry' anyway.

Gary406 · Post by **Gary406** » Mon Jan 31, 2011 8:10 am

cheers mate. i dont often use it below freezingso its good to know that for future reference
since my car is old it probably doesnt have the sensor
so i will make sure i dont use it at freezing temps ...

grasmere59 · Post by **grasmere59** » Mon Jan 31, 2011 8:49 am

The light comes on on the dash but i can't here the compressor cut in,i tried it later when the weather had warmed up a bit and bingo the compressor cut in so i reckon there must be a cold temp cut out.I suppose as the air from the vents with the A/C on is probably 6-7 deg what is the point if the outside air temp is less than that? I will keep an eye on it.

Post by **Welly** » Mon Jan 31, 2011 9:22 am

grasmere59 wrote:I suppose as the air from the vents with the A/C on is probably 6-7 deg what is the point if the outside air temp is less than that? I will keep an eye on it.

Indeed, you cannot treat or condition air if it is out of the normal operating range - it's a bit like trying to heat air that's already coming in at 55 deg C. In the winter our outside air is very cold and very dry - most of the moisture normally held in the air has fallen onto the ground as dew, frost, damp whatever. In the summer the air can hold a lot of moisture and this is where air conditioning can be of great benefit in de-humidifying for greater comfort allowing the body to cool through vaporising perspiration.

mjb · Post by **mjb** » Mon Jan 31, 2011 11:38 am

Welly wrote:it's a bit like trying to heat air that's already coming in at 55 deg C.

Given the coolant running through the heater matrix is 90 degrees...

Post by **Welly** » Mon Jan 31, 2011 11:57 am

You know what I mean Mr Pedant

406oc.co.uk

A/C question,

A/C question,

Re: A/C question,

Re: A/C question,

Re: A/C question,

Re: A/C question,

Re: A/C question,

Re: A/C question,

Re: A/C question,

Re: A/C question,

Re: A/C question,