Early automotive air conditioning

[electra225]

Packard had air conditioning in their 1940 models. The compressor ran all the time the engine was running. They hadn't invented dependable electric clutches yet. They opened a valve that let the refrigerant circulate without pressure. Horribly inefficient at best, with single-digit fuel economy on the big engines. Then along came Nash with their effecient and self-contained Kelvinator system in the early 1950's. Nash owned Kelvinator and they made appliances, so their entry into the automotive air conditioning business was a natural. Then came the Chrysler Air Temp system. After Nash was no more, the Air Temp system was king of the roost until GM's Frigidaire/Harrison division introduced their flooded evaporator systems in the middle 1970's. Frigidaire systems from 1953 to the middle 1970's had their share of issues, mostly clunky compressors (A5) and icing evaporators. Ford was never seriously in the air conditioning business. Their first factory air conditioning was in 1955 and ran on 6 volts. They used the same basic system until the 1970's when they put Frigidaire systems in the Lincoln and Mercury models and some of the higher end Fords. Ford factory air conditioning was an antique when it was new and never got any better. The only good part on Ford factory air was the switches they used on the evaporators to control the compressor. They were perfect for converting the early Frigidaire systems to a controlled compressor, thereby eliminating the trouble-prone POA valves used in 1963 to 1970. The best feature of the Frigidaire, introduced in late 1962 was the A6 compressor. It proved to be an industry standard for the next 30 years. Early Frigidaire systems, 1953 thru 1955 (Buick) was a two-piece system, with the evaporator and blower in the trunk, with plastic tubes that ran thru the package tray to put air to the car. Rear seat passengers had their ears turning purple with the cold, while sweat ran off the driver's nose. Horribly complex, with refrigerant lines that ran under the car to the back, subject to road debris and road chemical damage. The worst job I ever took on was to install factory air in a '55 Roadmaster coupe.

[walyfd]

Cadillac had it in 41. It was the same deal where you had to remove the belt to eliminate the compressor. The lines ran under the car and air was delivered from the rear package shelf.

I knew one member of the cadillac club that had an AC car. He said it'd freeze you out and he'd have to open the windows to warm up.

Oddly, once the war hit, it took another 12 years for air to come back in 1953. Packard was buying Harrison/Frigidaire units from GM. Even Rolls-Royce.

[electra225]

The Frigidaire/Harrison system was by far the simplest air conditioning system. Chrysler Air Temp was the industry standard for many years as the most dependable and the least obtrusive into the engine comparment. About the only chronic issue I ever knew with Air Temp was that on some models, rubber refrigerant lines ran too close to hot surfaces. The two-cylinder Tecumseh compressor they used was quiet and dependable. Chrysler controlled the compressor rather than the refrigerant. That necessitated using much simpler and reliable components to control refrigerant. Rolls, Jaguar, Rover, Bentley all used Harrison AC and Hydra-Matic gearboxes. Rolls, Jaguar and Bentley used Saginaw Gear power steering. The early air conditioning in Buicks was a horror show in the engine compartment. AC was built into and under the instrument panel in 1956, but the underhood plumbing was as bad as in earlier years. They never got the underhood mess straightened out until about 1959, then they used that silly system with cables controlling the electronics under the hood. In 1963, they finally used vacuum to control the system, better, then then the evaporators would ice up. In 1965, they got the icing under control, but then the blower wasn't strong enough. Seems like every time they improved something, it was at the expense of another system. The flooded evaporator system, with it's cycling compressor, finally solved most of the issues, giving GM arguably the best AC ever bolted to a motor vehicle. The R4 compressor wasn't as reliable or quiet as the A6, but it was smaller to accommodate smaller bodies and it pulled easier for improved fuel economy from smaller engines.

[walyfd]

Cadillac Climate control for 1964 was a relevation. Dial a temperature, set to auto and that was it. I never shut off a car without turning off all the accessories so... I was taught you didn't need radios and fans sucking starting amps.

1962 cadillac (maybe earlier) came out with the AC6 compressor. It runs all the time air is on but it had the suction valve. My car has 134 and, I'll be honest, it's better than the r12 91. I've seen these 62 systems frost the chrome air bezels. They don't regulate, you have to adjust the temp and flow.

[electra225]

I went to an air conditioning seminar one time where the instructor, a Mr. Sylvester, told us that a GM A6 compressor was capable of providing three tons of refrigeration in a motor vehicle. I remember his name because he did a Sylvester/Tweety Bird schtick in his technical presentation.

I had climate control in my '68 Electra. And in the '71. And in the '74. I was not impressed whatsoever. Why the Buick system was so mediocre, while the Cadillac system worked fine, is beyond me. Buick borrowed all kinds of parts from Cadillac, why not their climate control? I understand the Oldsmobile climate control worked fine as well.

[William]

My 1973 Buick Riviera GS had the A6 compressor, and yes it was a 3-ton unit. When an A/C temp gauge was inserted into one of the A/C vents in the car it read 35 degrees. It also had the auto system which I did not like at all. My biggest complaint was you could not add heat when it was on Vent.

Bill

[Firedome]

Then Frigidaire swash-plate compressor was probably the best ever, if not the most efficient weight/power-draw wise, 3 tons = 36,000 BTU, way overkill, we have a 24K BTU Mitsubishi mini-split heat/a-c in our camp! But Chrysler's V-2 compressor also worked well and was pretty bulletproof, my '59 DeSoto Firedome and '81 NY'er Fifth Ave had essentially the same unit virtually unchanged, they were that well-designed and dependable.

[Dr. Radio]

In the non-automotive world, I read that Frigidaire really cleaned-up when it came to sales when electric refrigeration came into being for home owners. It seems the name "FRIGID AIR" really was a clever play-on-words that actually did resonate with consumers.

Growing up, my parents were the 2nd owners of the house I grew up in. There was a circa 1967 Frigidaire electric range in the kitchen that made many, many delicious meals courtesy of Mom. When I was old enough to notice the details on appliances and such, I remember thinking it was pretty cool seeing the Frigidaire name, logo and stating "Product of General Motors".

I wish the A/C in the Chevelle worked. The seal in the compressor (among other things) went bad many years ago. I'm trying to get everything else going (electrical, vacuum lines etc), so maybe some day when the "budget" allows, I can get it working. Many folks swear by the cooling power of the A6 compressor.

And what a timely topic. I unfortunately discovered this weekend that the actuator pod on this item is no good. It won't hold vacuum when I tested it with my MityVac. I found some used parts on eBay so now that the wallet is lighter, I hope they work.

I know what this is (the device in question with it's actuator pod). So for fun, do you guys know what the purpose of said item is and how it work?

[William]

My guess, it's the actuator that allows recirculation of the interior air when controls are placed on "MAX", or it allows fresh air when in normal mode. I'm not sure what it says on the HVAC controls on the dash on your Chevelle but I'm guessing "MAX"?

Bill

[electra225]

Buick had separate acuators on the vents, so they would operate on vacuum via the climate control system. I would guess that one would be in the recirculation system.

[Dr. Radio]

I knew you guys would know your stuff.

This door works together with a flapper door up in the actual cowl of the car. When you place the A/C in "MAX" position, vacuum is applied to the orange tracer vacuum lines (there is a factory "T" to both control pods). The door in the cowl chokes off hot/humid outside air being drawn in by the blower motor. The blower motor now needs a new source to draw air from....thus this side cowl door opens up. This side door draws in the air that has already been cooled in the interior back into the blower motor to be redistributed back thru the A/C box and back into the car. By "re-using" the inside air, you are getting the "maximum" cold from the A/C system.

Now, the one catch is, and the owner's manual warns you, that if you leave the A/C control in the "MAX" position for too long, the air in the car will get "stale" as no new fresh air is being pulled in from outside.


Now another question for you guys.....

I'm using my MityVac to test the various vacuum pods and vacuum lines in the car since the dash is out. How much vacuum (Hg) should I be applying to the various components? I don't want to damage something and I don't know what kind of pull the engine would provide at idle.

Stock small block hydraulic lifter V8. Vacuum hose from the manifold is connected to a "soup can" (vacuum resovoir) underhood, from here it runs into the interior into the HVAC controls where it is then sent out to the various pods depending on what setting I select on the the 'ole slider control....

[walyfd]

Pull a vacuum hose from the carb area as if you were setting mixture and see what the engine vacuum is then use that number. I'd say 16 to 18 in hg is safe.

Or... if your ac dampers run off the vacuum tank, hook up the gauge to that and see what the tank steadily holds on the outlet side. You'll have to run the car again for it to refill and stabilize.