Please tell me how not to melt in my car.

March 18, 2009 11:36 AM

I'm driving around, it's not even 70 degrees outside, and the inside of my car feels like a greenhouse.

The interior of my car seems to draw heat. Even on a pleasant day that doesn't require air conditioning, the inside can get stifling.

I'm not talking about the heat that comes after leaving my car parked in the sun--I mean that even when I'm driving and the A/C is running cool, sometimes it's hot in my car anyway. I'll feel the A/C wherever it's blowing directly on me, but otherwise I and my unhappy passengers are surrounded by heat.

My car has a black dashboard and no real tint on the windows. Could this be the cause? My car is 9 years old and in decent conidtion, but I will probably buy something new in the next year or so. Is there a solution that's not too expensive, so that I don't bake in the warm weather this year?

Also, could a windshield tint strip help--something like this, or should I get it done professionally? Assuming my un-tinted windshield is the source of my misery.

Thanks

posted by luckyveronica to travel & transportation (13 comments total)

I'm assuming you've checked your cabin air filter?
posted by Thoughtcrime at 11:58 AM on March 18

Im guessing that the main issue is your AC not keeping up with the heat that accumulates inside the cabin. It may have a leak or other problem. Id have a mechanic look at the AC unit before messing with the windows or anything like that.
posted by damn dirty ape at 11:58 AM on March 18

Some of those dark-mesh suction-cup window-shades, like people with children sometimes use, probably wouldn't hurt. But they probably wouldn't make a big difference either. Professional window tint isn't cheap, but, if you live somewhere sunny, it might make it easier to sell the car, especially if you're selling it in the summer. Amateur window tint is not to be considered.

The most inexpensive solution is probably to either open a window or adjust the climate controls.
posted by box at 11:58 AM on March 18

Does the blower actually blow hot air? the diverter valve that lets coolant (hot water from the engine) into the heater core may be stuck open.

My old Impala - black roof, black interior - wasn't as bad as you seem to make it out to be.
posted by notsnot at 12:00 PM on March 18 [1 favorite has favorites]

Wow, I literally just noticed the same thing today. It's about 60 degrees where I am. I noticed that even though I didn't have the heat on, it seemed like hot air was coming from the dashboard vents.

My dash is also black and I eventually decided that it was trapping heat in that well along the edge of the windshield. Not sure if I'm right though.
posted by lunasol at 12:03 PM on March 18

Something I forgot to mention - if the car is warm when you get in it, roll the windows down and flush the air out for two or three minutes. It can make all the difference.
posted by notsnot at 12:09 PM on March 18

Your car is a greenhouse. All cars are, with lots of glass. The sun comes in through the glass, heats up the interior, especially your nice black dash, and then the glass traps the heat inside. It can be hard for your AC to keep up, but at seventy outside it should be able to. Have the freon level checked and consider tinting the windows.
posted by caddis at 12:12 PM on March 18

I once had some stuff fall down the vents, preventing a flap from fully closing. Might be worth a look.
posted by Harald74 at 12:38 PM on March 18

I can't tell from your question whether this is a new problem, or something you have always suffered in this car. If it's a new problem, then some of the possibilities posed by others -- stuck diverter, A/C going bad (the very low humidity caused by proper-functioning A/C can make a big difference in how the car's climate feels), or an A/C thermostat problem -- your A/C air should not just be cool, but be seriously cold when the car has been running for a while. Caveat: A/C problems can be like walking into an evil tar pit that sucks away all your money, since many mechanics only partially understand them and there are many separate components that can fail, even after you replace other parts (and lots of coolant lines that can break and then be difficult -- read: costly -- to trace down). (If you're saying to yourself that you're hearing the bitter voice of experience in said wallet-draining quagmire of frustration, you're right.)

However, if your car has *always* been like this then you might have an unfortunate combination of dark interior (always bad in the heat), expansive dashboard that soaks up and persistently retains the heat (my 96 Civic does this, and its dash is only dark gray), moonroof (I found this to be significant in letting in radiant heat as well), and weakening A/C. Good luck.
posted by aught at 1:07 PM on March 18

I once had an 82 Volvo DL coupe that was always unusually hot inside, rain or shine. It was a light cream color with a light tan interior and no sunroof. After a while, I became aware that the engine heat made its way through the firewall and that the entire dash area simply radiated heat. The ventilation worked fine but moving air is just no match for radiant heat and this is why radiant heaters work so well outdoors--the heat merely pierces through the moving air.

I mention this only as a possible course of investigation. It could be that your catalytic converter or other part of your exhaust system is damaged in a way that causes it to be very hot and the heat is making its way through the floor-pan of the car. The insulating material, if heated very, very far beyond its designed temperature limits can burn away over time and make the heating effect from the exhaust system more pronounced.

Another more likely possibility is that the heating system, usually a baffle door, is stuck slightly open and is heating your car. Try turning the air flow to "recirc" and see if the car seems cooler. Recirc has the effect of "turning off" the forced-air effect of outside air when the car is moving. This can help you isolate whether or not your heat is simply not being properly "turned off" due to a leaking baffle.
posted by bz at 3:39 PM on March 18

Seconding notsnot and/or bz... this sounds like heat is leaking in where it shouldn't.

This is way beyond window tinting or car color, air conditioning should rapidly change the temperature of the car, especially at 70 degrees outside.
posted by samsm at 4:15 PM on March 18

My car interior is sealed up so well that the blower doesn't work as well as it could because the inside of the car is "pressurized". I've found that by cracking open one of rear windows a half-inch the blower is able to blow more air out of the vents. I also get a little wind noise from the window but not much.

After nine years, your car may have leaked enough freon so that the A/C may not be working as well as it once did. You might want to check it by sticking a small thermometer in one of the vents. I think you should get air that is 45 degrees or colder coming out of the dash.

It is not hard or expensive to add a can of freon to most cars, if you are handy. I added a can or two to my wife's van every spring for three years until we finally got rid of it.

My car is silver with a light grey interior and it also feels like a green house on sunny days, especially when the sun is on my side of the car. It is not unusual.
posted by 14580 at 7:12 PM on March 18

Get one of those silver reflective things to put against your windshield when the car is parked. They help a lot, and only take about 30 seconds to put up or refold with practice.

Tint will help too. You can buy tint to install yourself at an auto parts store.

It sounds like something is wrong with your AC. Why are you even using it if it does not cool the car off? If you are not on the freeway, just open all the windows.
posted by yohko at 12:49 PM on March 19