Depends...is it an old car, or a modern one? If it's an old car, we can probably help you figure it out. If it's modern (newer than 1965) then you might be better off finding a forum about your car.
These posts about car swamp coolers bring back memories of an "air conditioner" my dad made for our '60 Ford. We lived in PA at the time but were driving cross country for a combination vacation and work trip for my dad. Now my dad wasn't a mechanic but he was a pretty talented scientist who worked at Oak Ridge a**** other places after the war. He made what he told us was an air conditioner (but really was just a swamp cooler) out of a windshield washer jar/pump that he bought at a junk yard. It was with great anticipation when he first turned it on when we reached the desert. Unfortunately this was one of my dad's few failures. His "air conditioner made no noticeable difference in the inside temperature of the car. His explanation of the failure was that "it just wasn't hot enough" for the unit to work. To the day he died at 100+ my sisters and still joked about that it "just wasn't hot enough" even though it was over 100 degrees outside.
My AC woes are legion... In Virginia it gets hot & humid. (96 deg +) (FLA, AL, SC, LA, and TX are worse). Godless cruel humidity is the criminal here. Southern folks know what I mean. Y'all get it. You guys out west in dry climates or in cool Michigan DONT. No offense. Death Valley residents? Maybe. My 56 Premiere has the "heavy duty" V.A. system with a 7-vane compressor. The condenser/fan unit is in the trunk. This system only works at dusk or in the morning when the strong sun is low. Fan is wimpy. WTF? I'm not expecting Jesus-grade miracles here, but its almost useless. • Old cars usually don't have the thick UV windows of today, body interior insulation, and those big engines put heat through the firewall too. • Rubber trim has to be well-fitting and in good shape. • Try mylar insulation too. These are good points to remember! Firewall insulation is a must. Funny factory R12 AC stories: My old 67 427 Vette 'vert had the factory AC---what a joke! Why, GM....why? My 60 Caddy CDV has the factory R12 setup. All rebuilt. What a pain. Its good & strong, and cools effectively until around 92 deg, then all bets are off. Open the f••kin' windows. But its still better than the V.A. setup. WTF? (BTW...R12 is available in 30 lb cans ---the US Military has megatons of it.) Why the aftermarket cant or won't come up with an affordable a super-duty R134 AC system is beyond me. We need one with a powerful fan. Mack truck worthy! Also, 3M has some mild 30% UV window film that might help. Havent tried it yet. Not too dark. Theres a good reason Chrysler and Ford put dual AC condensers & fans front & rear on their early 70s wagons. My Mom had one with a 440 4V. I could kiss those dang engineers.... In my opinion, all those aftermarket AC companies need to test their systems in a 55 Chevy wagon in Huston TX in July before making their BS "heavy duty" claims. Expensive option: Dual compressors and multiple condenser/fan units. I've seen it done on a 56 Imperial. 175 amp alternator is necessary. The builder did it for some Middle Eastern customers. 75 deg cabin in a 130 degree desert. No ****.
We put a-c in nearly every car we build; it's Texas! Usually use Old Air but absolutely nothing against Vintage and cost is the same. If you are in the build stage then installing an under dash unit up in the dash gives two big pluses, no knee knockers and instant heat/cool with no ducts to cool down or heat up. Needs to be done while still slicing and dicing, not on a finished ride. The 30 Plymouth has no grill so condenser is under floor pan with two cooling fans. Had to use R12 with tiny unit. 39 Ford with in dash unit: 1930 Plymouth with in dash a-c:
I have AC in all my cars. I screwed up once, saved a few bucks, and bought a system that is well known for being cheaper. I will never use another system other than VintageAir. There stuff is well engineered and it works. The underdash units are pretty rudimentary. The newer units that install behind the dash have electronic servos to blend temperature and humidity control. A great upgrade. In AC, like everything else, you get what you pay for.
50 Degree air is not really chilling properly. A system that is in good shape should be able to put out 40 degree air easily. 90-100 degree day here in Texas my vintage air unit will do39 -40 at the duct
John W I’m sorry to hear of your fan problems. An old air products unit does not blow over the heater or AC evap but ****s thru them. I have 4 vents and the one on my wife has a 3/4” hole in a cardboard washer to slow it down. After initial cool down you can’t sit in the car above low speed on the fan. The electronic controls allows no engine coolant heat to the interior but circulates the coolant under the hood unless you turn the heater on. It’s in a full size 56 Ford. Good luck…
There’s a HAMBr that does just that. Popped up on a thread a few days ago (couple years old) about rebuilding a swamp cooler.
Sorry, but you're wrong. I've done a fair amount of auto ac work in my job when I worked as a professional mechanic, and IME getting 50* in the vents is about the best you can hope for. See this: https://autoacrepair1.com/how-cold-should-my-ac-be-at-the-vent-in-my-car/
So a test is done on max recirculating air and windows down? That’s one I would have never guessed. Aftermarkets VA, OAP, etc are recirculating only as I can see. I left the right front air vent cable and flapper in my car so I could add “new” air as needed near the AC inlet under the dash.
I put VA in my 49 Buick and it works great. Used the under dash unit with defrost. It really helps to have good door gaskets, and have the doors and roof well insulated also, to get the most cooling from whatever unit you buy.
Not my first Rodeo either,,, I can get 40 deg air from my latest install at the center duct... No matter what that article says.
Nothing that I own does not have air,, My good cars will do 40 deg air and sometimes 45 if humidity is up, I get 40 deg air out of my latest truck at center duct no matter what that article says..I have put in all vintage air units and heavily insulated the cabs. I have been around awhile also. It is not uncommon with humidty around 20% to see evaporator temps at 35 degrees..
An old mechanic I trust said that most of the factory Big Three R12 units from the late 60s early 70s had 32-34 degrees out of the ducts. Big Caddy, Lincolns, Chryslers. I know that when my 61 Lincoln blew air it frosted up at the vents. Just an FYI.
I don't have my vents in yet. I have been too busy with other things. This put out 48ºF from the center vent, in the 70ºF shop, with about 60% humidity.
Had one of the Mark IV under dash units in my 59 ElCamino in 1970. It took up some middle seat leg room but that ****** would freeze you out of that Elkie in the middle of July in Waco. It made what little gas mileage that the 235 got even worse though.
Why would they? Most of us are not having trouble with the Sanden 508. Also, R134a is ending its on January 1, 2024. R12 has not been used in a new vehicle since 1994, and has been out-of-production since 1996. It came to an end on January 1, 2021. There is a $10,000 bounty that the EPA will be happy to pay to anyone who rats you out using R12.
"We need one with a powerful fan." Be careful what you wish for, the fan noise gets overwhelming. I've installed 4 aftermarket AC units over the years. All of them had so-so power on the fan. I could not stand to listen to the fan on on the "HIGH" speed setting.
That doesn’t make sense that an OA product would make the engine warmer than anyone elses unit. They all use the same compressor and condensers. Because of compressor location I have a VA mounting to an OA evaporator and yes the temp on the engine went up and on high fan I can see a higher load on the alternator and at 27 amps total that can cause addition engine heat. But all the fans add temp from an alternator and compressor. I live fine with 190-200* on a hot day with the AC on low or mid fan and true the engine does run 170* on a normal day with no AC on.