[Molon Labe]

I'm installing A/C in my '67 Fairlane and was wondering about the location of the drier. Is there any advantage to locating it closer to the condenser or the evaporator? There's a good spot to locate it on the fan shroud a few feet from the condenser outlet. I'm thinking that would be a good location temperature wise while keeping the clutter under the hood down.

 

[2old2fast]

GM used to mount them off the evaporator core , thats my only reference ..

 

['49 Ford Coupe]

There is a difference between a liquid line drier and a suction line receiver. The liquid line drier can you go anywhere in the system after the condenser Outlet.

 

[DesertXL]

I'm installing A/C in my '67 Fairlane and was wondering about the location of the drier. Is there any advantage to locating it closer to the condenser or the evaporator? There's a good spot to locate it on the fan shroud a few feet from the condenser outlet. I'm thinking that would be a good location temperature wise while keeping the clutter under the hood down.

Hello Molon Labe,

On a system with an expansion valve you'll want the receiver drier closest to the condenser and here's why. The receiver drier is meant to ensure a steady supply of liquid refrigerant to the expansion valve, which of course feeds the evaporator. If you move the receiver drier closer to the evaporator you are exposing it to more engine bay heat (from radiator) which will enhance boiling off refrigerant in the drier and make the air con system less effective. That is why you'll never see a receiver drier mounted behind the radiator, it needs to be closest to the front of the vehicle as possible and it usually right beside or in some older Fords actually integrated in the original condenser. 3rd generation Ford full size 65-68 have a special receiver drier that is part of the condenser so to speak. Whereas late 60s through mid 70's GM usually had the receiver drier connected right after the condenser on the side of it.

Now on a system that doesn't use an expansion valve to control the superheat, they use the more modern accumulator and that is placed closest to the evaporator and here's why. Modern systems that use the cheap orifice tube for a pressure drop can't control the superheat all too well in the evaporator, as a result under certain conditions you will have liquid refrigerant coming out of the evaporator. The compressor can't handle liquid refrigerant and you can damage the reed valves if allowed to suck liquid refrigerant. The accumulator being connected after the evaporator (whereas the receiver drier is connected before) allows any liquid to accumulate at the bottom and boil off to a gas from the engine bay heat and ensures a constant flow of gas back to the compressor.

Hope that helps a bit.

Cheers

 

['49 Ford Coupe]

Theoretically, DesertXL is correct. However given the huge volume to surface area ratio of a dryer the increase temperature by the time it gets to the expansion device is pretty much immeasurable. A properly charged and operating system will have subcooled liquid leaving the condenser which means the liquid refrigerant is actually cooler than the condensing temperature of the condenser. That change of state from gas-to-liquid takes a lot of energy. And it takes a large amount of energy to change that liquid back to a gas which won't happen even if the surroundings are quite hot. All that counts is that you have a full column of liquid entering the expansion device. Hopefully the o p is going to put a sight glass type dryer on it and when he charges it he will use the combination of watching the pressures and that sight glass to assure a full charge of refrigerant.

 

[Molon Labe]

Sounds like I can mount it on the grill side of the radiator support/shroud and I'll be fine. Thanks guys.