Why was A/C back in the 1970's so cold?

It was the early 90’s, I had a 77 ltd that had r-12 and a compressor that looked like it weighed 50 lbs. It probably held 3lbs of freon and it sapped power and contributed to the hole in the ozone but by gosh it was cold. I remember on a hot day if you had the a/c on full blast and opened the door, you could see the air condensing out of the vents like a fog machine. ICE COLD AC… Period.

I have a friend with a 74 buick electra 225 and we measured the output of the a/c and it was 37 degrees, if you drive the car with the a/c on max on a 85 degree day you can get the interior of the car down to 45-50 degrees in the back seat.

My question is this, we know a/c units are more efficient and earth friendly these days, but why are they not as cold, is it the refrigerant or a smaller system, or a combination of both.

In retrospect, there is no reason to have a/c units in cars that have the capacity to cool a small house, im just wondering.

We just bought a brand new car and it takes forever to cool the car down with the a/c on max when used on a hot day. Thats why I wonder.

I’d say it’s a combination of both. The newer refridgerant isn’t quite as efficient at the older banned stuff, but it works well enough. My '11 Cruze’s AC gets pretty chilly, for what it’s worth.

So, Rick, what kind of car did you end up buying?

@DrRocket I think Rick said he bought the Caprice 1988, and his girl will buy a new Honda Civic.
My 1988 Caprice had an industrial strength A/C, but the mileage dropped quite a bit with it on.

I have no complaints about ac, though I have no point of comparison as the first ac car was in 1990. I used to think it a luxury, but now consider as a necessity, spoiled rotten I am.

Those cars with the old A6 compressor usually blew ice cubes in your face, but the system capacity was often 3 pounds or more!

Many cars nowadays barely have 1 pound.

The low point for me was our '95 Suburban, one of the first years of the R134a, it would NOT cool off a load of folks during the summer. Not good.

@texases not to excuse GM, but a Suburban has a lot of cubic feet to cool down.

True, but this had the front+rear a/c, never had a problem with prior GMs.

Several years ago a drop in brought his early 70s Dodge to me and hoped the AC could be made operational at a bargain price. The fan speed control was shot and a hose was leaking. After replacing the hose (bulk, by the foot) and charging the system it worked well but only with a jumper on the blower’s high circuit. The customer seemed happy that it worked at all and drove away on that hot day but in a few weeks returned hoping I could give him some relief from the all or none AC. His daily commute was 20 miles each way and with the AC on it blew such a blast of cold air that his eyes and nose would dry out. I was able to add a resister and slow the blower somewhat but those old V-twin Chrysler compressors were vastly over built for the car even in the hot and humid southeast. Fords were a close second on the scale and GM was at the rear of the pack but the old Harrison unit was more than up to the task while being significantly smoother and quieter than the competition. Those old compressors could have cooled a nice home.

My parents bought a used 1963 Buick LeSabre in 1966. The Buick had been fitted with an aftermarket Mark IV air conditioning unit made by the Mitchell corporation. It could get the car so cold that you would think you were riding in a home freezer. I know the unit didn’t bring in fresh air–it just recirculated the air in the car and it hung down under the dashboard taking space, but it really cooled well.

If you drive a Ford Panther platform car, you STILL can enjoy A/C that will freeze you out of the car. Even driving down in Mexico, Sonora Desert, I have never needed the “Max Cool, High Fan” setting…

I once owned a '56 Caddy with roof air. The compressor was massive and yet that sucker would cruise effortlessly at 90mph on a hot summer day. Now that I’m quite a few decades older I’m far more concerned about the performance of my heater…

I don’t know that a blanket condemnation of all modern A/C systems is true. Some work great and some maybe not as great. The A/C on my Lincoln is great even with EATC that only allows a minimum 60 degree setting. The outlet air is still sub-40 on a 100 degree day.

Referring back to db4690’s comment about refrigerant capacity, my memory seems to recall that the refrigerant capacity on my oldest son’s '96 Camaro is something like 12-14 ounces and that’s atrociously little.

My 1999 Cavalier cools better than my old '79 LeSabre. It probably has to do with the fact that it has a smaller volume to cool. I checked the Cavalier’s output in the severe summer of 2011. It was 108 outside and the air coming out of the vent was 39-40. Having that blowing on my hands was painful. I never checked the LeSabre’s output temperature, but the (much larger) interior never got as cold as my Cavalier does.

I feel today’s AC are much more efficient and sap much less energy. They are as cold as they have to be to do the job…but no more. Why have an AC with the capability of lowering the temp to 50 degrees on the hottest days when 60 is sufficient. The climate control on one of my cars never blows too cold air, which can be unforfortable for some and produce uneven temps. They are better and probably work below capacity for longevity.

By far the best A/C I’ve had on a car is on my 1994 LHS. That system puts out colder air at idle than most do on highway cruise. When it cycles on, you can see fog come out of the vents if it’s a humid day. Very nice. By comparison, my 2006 300 has adequate cooling, but certainly takes longer to get in the comfort zone. Probably the next best A/C I’ve had was on either the 1987 LTD I had or the 1980 New Yorker I had… until both developed severe leaks that weren’t worth fixing anyway. The worst I’ve seen is on a friend’s VW. Just pitiful.

IMHO the trend to put less refrigerant in the systems is just stupid. Maybe better for the environment in some sense (though they’re not supposed to leak anyway), but not good for creature comfort. A system that holds more will still cool pretty well if it loses 10% or more of its original charge over the years. A system that holds a thimbleful will blow tepid air, and you’ll probably let loose more refrigerant into the atmosphere just connecting the charging hose or when consumers try to recharge themselves with those cheesy all-in-one cans than an older system that holds more will leak out. What is the point? Next will they decide to reduce the amount of radiator coolant and expect it to be able to handle engine cooling demands? Maybe they’ll make air bags smaller to save weight. It’s the engineering equivalent of a restaurant giving you one cocktail napkin to go with your meal.

A little story that may reveal something about A/C size in relation to what it’s supposed to do.
Back in the 80s some Subarus used add-on A/C units with some installed by dealers and others installed at the ports of entry into the U.S.

A gentleman had purchased a new Subaru in Shawnee, OK, had A/C added to it, and a few months later moved to my area. It was spring when he bought the car and had now become full fledged summertime. The A/C would barely cool at all even on an 85 degree day and even then would leave the car’s occupants sweating a bit.
The gauges showed pressures were normal on both high and low sides, condenser fans operational, and there was not even a condensation drip on a humid day.

So I evacuated the system and recharged it. To my surprise it took less than one (small) can of refrigerant. Evacuated it again for a longer period and the same thing happened again so I then decided it was time for a closer look at things.

A close look at the A/C condenser with a trouble light showed the condenser measured about 11 x 11 inches square; roughly the size of a sheet of printer paper. I had never, ever seen such a small condenser as it was more the size of a trans fluid cooler. Now really curious, I pulled the glovebox and lower kick panel from the passenger side dashboard and discovered a dinky, downsized evaporator that was about size of a small box of tissues.

The system was simply too darn small to cool even a small car and the customer, who was expecting warranty to pay for his “factory” A/C unit repairs, was quite uset when given the news that the entire unit needed to be removed and replaced with something else. Last we heard he was going back to the selling dealer and let them have it but we never did hear any final disposition over what happened.

Back in the 1970’s, air conditioning was sort of an add-on to the heater. So instead of a large volume of air being passed over the cooling unit - which is the most efficient way of cooling the interior - the units developed colder exit temps - and that makes it appear that they were better back then.

Nowadays, it is uncommon for a car NOT to have air conditioning - and the cars are designed for it - large air volumes through many duct openings.


I agree, the a/c units of the 70’s were oversized to the point they were stupid, but the new systems have gone too far IMHO. I do remember back in the day, my family had a 1975 or so ltd with a/c. it was a wagon and the a/c would cool off the way back to a decent level even with no rear ductwork, however I seem to remember my father saying that the a/c caused a 3-4mpg drop. Nowadays I dont think the a/c hurts fuel economy as much, but maybe it does, i don’t know.

That beast would easily get down to 6mpg towing a camper with the a/c on and 6 people inside.

As well as cooling the air, the air conditioning system removes the moisture from the air. In doing so, a person feels cooler because skin moisture evaporates more quickly into dry air. I know that a room air conditioner needs to be “sized” to fit the room. If the air conditioner has too much capacity, it cools the room too quickly without removing enough moisture and the room feels clammy. I purchased an older house that had an enormous 240 volt air conditioner installed through the wall in the living room. This air conditioner was oversized for the room. Fortunately, there was a cold air return for the heating system on the floor directly below the air conditioner. I turned on the furnace fan (without turning on the furnace) and not only was the living room more comfortable, but I had the equivalent of whole house air conditioning.
I would assume that manufacturers size the air conditioning capacity to fit the vehicle. I do know that some compressors cycle on and off (my 1971 Maverick was this way and I could feel the compressor coming on while I drove the car) and some systems actually blend some heat from the heater core to regulate the temperature with the compressor running continuously. This latter system supposedly provides better humidity control.