Automotive Air Conditioning Information Forum

There's been a lot of stories lately about Death Valley and it's often seen 120+ degree temps and it got me thinking, do AC systems in vehicles even work at all in those types temps? I remember visiting Las Vegas in the mid '90s when they had record heat at the time, was 115+ degrees for the few days I was there. I remember my car - a late 80's 3 series BMW - was unable to cope with the heat. That is the AC just blew hot air.

So I wonder, do new cars that are sold in the areas around Death Valley have more robust AC systems than cars sold in other areas of the US? Or does AC simply not work at all if it's 125 degrees outside? I have no doubt a well insulated car like a Mercedes will do better than an econo, bare bones vehicle. Still that's a lot of heat to overcome for any AC system. Thoughts?

Every A/C system I run copes with 110-115F heat here in Texas and a good bit of humidity for that kind of heat. Last year we had numerous days that were both insanely humid and hot, think 105-110F and 50-60% relative humidty. Real feel over 120F. I get mid to low 30s at the center vent driving down the road and 45-50F at idle in that kind of weather even in my 80s and 90s GMs. The dual evaporator system in my 1997 Express conversion van cools that van like a refrigerator. Ceramic heat rejecting window tint is an equally important piece of staying cool. All the rear windows are limo tinted and I cheat a bit on the front windows as well.

This was an official 109F and 20% RH day. The measured condenser air inlet was reading about 115F and 26% RH at the time. I barely felt like standing in the heat long enough to get the measurements. This system cools noticeably better above 40 mph with even more airflow across the condenser than the clutch fan provides sitting stationary at 2,000 rpm. After 30 minutes at highway speed the blower fans are on the 2nd or 3rd notch and usually kick off recirculate. I ran the front dash unit flat out for 250 miles a couple of years ago because I was sunburned and had a couple of people riding with me covered up in blankets in the back even with the rear unit off. I have zero doubt this 97 would tow a 8,000 lbs trailer through death valley with the ac nice and cold.

https://youtube.com/shorts/d_wkF47r5Kk? ... IyeKC6Ch7T

That van has a parallel flow condenser, 9 bladed duramax fan blade, Four Seasons 10 cylinder 210cc HT6 replacement compressor, a Red Ford orifice up front and a Old Air products TXV for their Hurricane unit in the aftermarket rear evaporator setup. Far outperforms stock at idle and slow speeds but it has always been thar cold going down the highway.

We hava a 2011 Pathfinder and 2019 Titan and both will freeze you out on the hot, muggy days here. No doubt they would cool equally well in the dry desert heat.

TheGoldenCheetah wrote: ↑Mon Jul 08, 2024 6:03 pm There's been a lot of stories lately about Death Valley and it's often seen 120+ degree temps and it got me thinking, do AC systems in vehicles even work at all in those types temps?

Or does AC simply not work at all if it's 125 degrees outside? I have no doubt a well insulated car like a Mercedes will do better than an econo, bare bones vehicle. Still that's a lot of heat to overcome for any AC system. Thoughts?

Yesterday, I was in Phoenix AZ and the official high was 118F. I drove down from 5000' in the morning, went out to Home Depot to buy a new electric anti-siphon valve for my sprinkler system, AC in my 2004 Frontier worked great, but it was only like 108F at that time, and I was parked in the garage before going to HD.

After returning, I cut off the old valve, extended the 3/4" PVC pipes, glued on new electric anti-siphon valve, then got to my yardwork. I cut branches/fronds with my pole saw, mowed the 1000SF lawn, vacuumed the above-ground pool, maintained the vintage 1988 spa, finished about 2:30pm. Yes, it was quite hot in the sun, took water breaks....

Yes - Death Valley is hotter. If every vehicle was engineered to work great at DV temperatures, they would be over-engineered for the remaining majority of folks. Manufacturers like to keep costs low....

The home AC had been set to 90F (it's highest), and by 9:00pm was down to 85F....

^I'm glad to hear about these experiences, makes me think our vehicles would do ok - at least my wife's anyway, lol. 110+ is crazy hot, I'm amazed how well the AC systems cope with it.

The general consensus I've read over the years is that for all GM's other faults, one thing they really have down is AC. Many consider them to be the best. Makes me wish I could transplant a good GM truck AC system into my own car, lol. I'd love to have a system in my car that could drive through 125 degree heat and make it so cold in the car you need a blanket.

Mordern our old. The coil, cond, and compressor size will still matter. As mentioned, not all vehicles are designed the same or for a specific market.

Atleast in fullsize truck/SUVs and vans, GM has the a/c system down. Nissan/Infiniti also has it down well in their fullsize cars like the G35 and M56S I owned and their rear wheel drive SUVs and trucks as well. The smaller 4 cylinder cars always seem to sacrifice A/C cooling for fuel economy. Electric cars have the worst AC of anything I have ever been around though. I have driven a newer Tesla in Texas heat and humidity and it was a sauna inside even after an hour at highway speeds. The electric compressors just do not move the BTU a belt driven compressor does.

This is the first I have heard of a Nissan product having AC that works well

tbirdtbird wrote: ↑Wed Jul 10, 2024 9:00 am This is the first I have heard of a Nissan product having AC that works well

I have owned 3 older body style Titans (2004, 2012 and 2014), and a 2011 Infiniti M56S. My mom has had a 2007 G35 sedan, 2011 V8 Pathfinder and a 2019 Titan. Every single one would cool mid to low 30s center vent in 110-115F weather with the blowers on high fan speed. They would hold mid-low 40s at idle. The Pathfinder was not quite as cold at idle because it has a dual evaporator system but it would still freeze you out with all the airflow from dual evaporators. 2 of my Titans and the M56S were at a severe disadvantage being black on black or black on charcoal interior and the 2014 Titan and M56S were black leather. Those Nissan/Infiniti products run right on the edge of freezing the evaporator core into solid block of ice given the discharge temps.

tbirdtbird wrote: ↑Wed Jul 10, 2024 9:00 am This is the first I have heard of a Nissan product having AC that works well

Don't jinx my 1998 and 2004 4-cyinder Frontiers in Phoenix !!!