derekh25

Ok, I understand the benefit of having the A/C on and off during the summer, but what's the benefit of having it on during winter, when you're trying to heat your car? It seems to heat up the car at the same rate regardless if the A/C is on or off. Does anyone know any details about the difference? Any benefits or drawbacks to having the A/C on or off? (Gas mileage, etc)

Thanks,

Derek

neo661

sup brotha?

i recently took a road trip from LA to Mexico and had to drive the hot deserts of Arizona having the AC on practically the whole time didnt adversly affect my average mpg but it did put a little dent. nothing too significant.

during the winter, which there is practically none in SoCal i have the AC on with the temp around 80 or so. it heats up pretty quick...atleast in my car. and with the heated seats its really toasty....

LukeaTron

It's generally done to dehumidify the air. It does help a good bit to keep the stuffiness factor down when you've got the heat blasting. It helps to keep the windows from fogging too.

The AC steals less HP in winter versus the summer. In the summer, the compressor is working hard to compress the gaseous refrigerant back into a a liquid because it doesn't cool down as much when passes through the condenser coil (due to the ambient temperature being higher and creating a smaller temperature gradient with which to 'suck' the heat out of the refrigerant). In the winter, the outside temperature is low enough that the gaseous refrigerant readily condenses back into liquid form in the condenser without the need for increase in pressure.

Basically, the AC is sucking heat from the inside of the car and dumping to the outside. When it's cold outside, the job is much easier since the cold air will readily absorb excess heat. When it's hot out, the energy difference is between the outside air and the refrigerant is not as large and the AC system has to forcibly expel the energy (heat) it has absorbed from the inside air out into the outside environment. It does so using pressure created by the compressor.

davidspalding

(what he said) A/C removes moisture from the air. In my 1982 Accord, the windshield defrost worked in SECONDS with the warm air conditioned, removing condensation from the inside windshield. Some nights, it wouldn't de-mist the window at ALL using outside, heated air.

Not sure if it's a big diff' in the TSX, but the other night, my windows started fogging up and kicking the a/c on cleared it up quite quickly.

CR did a study of driving at 55 with and without a/c, and noted not a lot of MPG difference. We've come a long way from the old days....

snailspeed

Also turning on the A/C once a week for >10 min during the winter helps keep the oil in the A/C system to circulate and lubricate seals and stuff... that is why so many people have A/C problems, they don't use it until the summer season and all that time, the oil did not lubricate the system, causing failures.

ATsxMan8305

Good point snail, as my dad (30+ years in the HVAC business) always told me to do that. It seems that different cars fog up (in the wintertime) more so than others. On a scale from 1 (never fogs up) to 10 (always/annoyingly fogs up)...I would rate the TSX a 7. My old 98 Chevy, a 4. With that said, i'm wondering if there is something you can purchase that you can apply to the interior windshield that will help eliminate the fog problem on those cold/humid mornings.

Simba91102

Climate control display is set at 67 AUTO 12 months a year and I pretty much never have to touch it. AC runs whens it has to.

davidspalding

Aviation instrument glass cleaner. As I recall it had something like .5% silicone or something (was labeled "siliconized glass cleaner"). Used to use it all the time in the USCG. Works better than Rain-X (for a short time) on outside windows, too.

Wish I had some today. Not cheap, either.