OT Car air conditioning...

chuck2015

Member
Just had this repaired on my car, a nissan versa. My question is this....is it normal for an air conditioner to have a difficulty in really(over 90F) hot weather to provide cold air to the car interior?
 
Maybe depends on the car. I have an 05 ram
that barely keeps cool at 90-100?, but a
grand caravan that will freeze me out in the
same weather. It also could have something
to do with air mixing doors. I would assume
it should keep up at 90?
 
I agree. It depends on the vehicle.

I once had a '77 Ford Mustang II with a dealer installed, add on, air conditioner. It was the best air conditioner I've had in a vehicle, ever. If you kicked that sucker on on a hot, humid day, it would blow snow out of the ducts.

On the flip side, I've had vehicles with A/C that was only so-so, even when maintained to factory specs.
 
That Versa is like my Honda Fit in size. The Honda fit is known to not have that good of an A/C unit. Just not a lot of room to put it.
Try and google your car and see if many have complained about poor A/C performance.
 
Should be able to keep up if you are driving but if your not moving a lot it can have problems. The bosses Nissan SUV does not keep up well unless its moving,now my ford trucks will freeze you out!
 
Put a thermometer in front of the center outlet with the AC running and check the temp; it should be high 30's to low 40's degrees. If it's around there, that means it's running about as cold as possible and there just isn't enough air flowing thru the evaporator to cool.

If you could actually measure the temp on the evaporator, it will be about 35 degrees, the air warms a bit traveling thru the ductwork.
 
My semi truck will just keep up at 100? and over. My old truck wouldn't quite keep up atbanything over 100?.
 
First check and confirm that compressor is running. (jumper the pressure switch if necessary then your positive). Then add a can of refrigerant ( $5 for can or $35 for can and kit).
Long stem thermometer in air vent will tell you much. After that the chances increase that your compressor is going bad.
I just repaired two cars yesterday; both have minor leaks and need a can of refrig every two years.
Good luck Jim B
 
My 2007 GMC blows cold air almost right away using inside or outside air. Buick takes a mile to two. If it really hot and humid, don't bring in hot air, go to recirculating the cabin air.
 
Goose, that reminded me of an old Dodge 1 ton farm truck I worked on many years ago. Belonged to a dairy, they bought it to pull a cattle trailer.

It was a real piece of junk! The engine blew immediately, ended up pulling the old wide block 318 out, put in a 440 automatic.

It originally had factory air, but everything was gone but the evaporator, and it had been open for years.

I scrounged up a used compressor, condenser, cobbled up hoses and whatever else I could find, put it all together...

That truck had the coldest air of anything on the dairy! And it held up, no leaks or rattles!
 
Must be a Nissan thing. We just rented a Nissan for a vacation and the air conditioning could only cool about 10-15 degrees below outside. Made it kinda awkward going across the Mohave Desert.
 
Assuming that the dealer put it on your car, those old Tecumseh/York compressors worked very well and were quite dependable for their day. My '71 Cougar's AC with R12 still works great.
 
At 95 degrees my 1992 F350 will freeze you out of the cab when going down the road, and keep you very comfortable in stop and go traffic. None of my newer Ford F-250 would do that, especially bad in traffic.
 
Get up tomorrow morning and go out to your vehicle, raise the hood and start it up. Set the AC to internal (recirculate), full cool, fan on high and
hold the accelerator down to something like 1500 rpms give or take for 5 minutes.

Get out and have a look at the compressor connection tubes. The small one should be warm to the touch and the large one should be sweating at
the compressor. If not, you are low on freon. If low on freon you can't expect normal performance.

AC coils usually have a 30 degree (dry bulb) temperature differential between input freon and out put air. The inlet difference will be 30F cooler
and the exhaust will be 30F hotter assuming that the air flowing across the coil meets the minimum velocity requirements for the unit's design.
Since the system is a closed loop, it has to follow the ambient meaning that the cooler it gets, the cooler it gets.

The big problem used to be the engine driven fan wasn't moving air adequately across the condenser coil to pump the heat out of the refrigerant
passing through it, like at idle, sitting in traffic. My 2011 Silverado has 2 sequential electric fans. If stuck in traffic or whenever the need arises,
the thermostat turns on one normally, or on really hot days both and I guarantee you, the inside is cool and comfortable, and as Geo-TH said,
recirculate cabin air, at least till you get out to the open road if you want more cooling since you aren't mixing hot outside air with the cabin air that
is going across your evaporator coil inside the cab........but sooner or later you need some oxygen to breathe. Grin
 

If the car is equipped with a cabin air filter, either replace it, or pull it out and trash it. It's the same thing as the filter in your house hvac system.
 
The effectiveness of a car's air conditioner is dependent on the sizes of the evaporator, the condenser, and the capacity of the entire system. Due to sun load, large glass area, and relative lack of insulation, most automotive A/C systems are of really high capacity.
You can check for the outlet temperature of the air nearest the evaporator. On a 90 degree day in the sun, it will only get to about 45 degrees. The suction line should sweat most of the way from the evaporator to the compressor. If these conditions are both met, you are getting about all you are going to get from it.
You can maximize the effectiveness by using the recirculate setting and a mid speed on the fan. This will keep cooling the air inside the car that is already cooler than the outside air being brought in. Using the highest fan setting does not allow the air to be properly cooled as it passes through the evaporator. Air is a poor conductor of heat/cool. As such, if it spends a bit longer passing over the evaporator, it will be cooler as it passes through the registers into the passenger compartment.
 
Here is what my 2004 dodge cummins puts out of the duct on the drivers side next to the window and still has all factory parts
38554.jpg
 
Must be a Nissan thing with bad A/C. My 2014 Sentra quit blowing cold air 2 years ago, just kept driving with the windows down in hot weather, kind of got used to it. With all the hot weather recently, I put in a can of refrigerant and it just leaked out. Figure I'll take it in eventually, just too lazy, I guess. Easier to just roll the windows down.
 
(quoted from post at 04:07:18 07/29/16) Here is what my 2004 dodge cummins puts out of the duct on the drivers side next to the window and still has all factory parts
38554.jpg

Your thermometer is reading a few degrees low; for the duct to be reading at 30, the evaporator is in the 20's. That won't work because ice will form on the evaporator and block the air flow and you won't get any cooling. The evaporator always runs above 32 degrees if you want cooling for obvious reasons.
 
Nissan should have a performance test for the air conditioning system to determine whether it is performing within limits. The one's I've done on Chrysler's were at operating temp., engine at 2,000 rpm's, blower on low speed and center duct panel outlet temp., depending on ambient, low 40's to high 40's. I can't remember if they wanted max A/C.
 

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