Automotive Air Conditioning Information Forum

Receiver Filter Drier selection questions

Any reason not to use the biggest Receive/Filter/Drier available?
What are the thoughts on bigger vs smaller Receiver?

I have room to put the largest Receiver I found so far - Four Seasons 33345 with a canister that is 7” tall and 4” in diameter (88 cubic inches). For reference the OEM r12 system had one that was 7" tall and 2.5" in diameter (34 cubic inches).

What I see so far is:

- Pros
1) I’m thinking they make Receivers in different sizes for a reason. For my build I have the largest evaporator I could find at 32,000BTU so maybe the largest Receiver makes sense?
2) A bigger Receiver (likely) has more desiccant providing more moisture absorption/protection.
3) A bigger Receiver can hold more refrigerant allowing for more refrigerant reserve and allowing for full use of the whole surface of the condenser before the lower condenser section starts getting filled up with liquid.
4) A bigger Receiver would allow for more refrigerant reserve so the system would likely continue to work longer if there is a minor leak.

- Cons
A) It could take more refrigerant than minimally necessary to make a functional system.

Thanks in advance for your thoughts on this and if you happen to see some idea/concept my novice eye doesn't see, please mention it.

Andy

This project:
Make/Model: VW Vanagon applicable to years 1980-1991 with a Subaru EJ25 engine
AC system type: CUSTOM
Compressor - FS10
Condenser - 16x24 Parallel Flow Generic
Evaporator - 32,000BTU/610CFM
Hose - reduced barrier lengths (approx.) #6-25ft, #8-20ft, #10-8ft
Trinary Switch - SW psi triggers L 28open/29close H 454open/369close Fan 227on/185off
Refrigerant - r134A
Receiver/Drier - TBD

I am pretty sure it does not really matter. A FD of 4" diameter is huge and in my world I have only seen that size on a refrigeration system. The OEM size would be adequate.
Your items 3 and 4 do not hold water.
Neither does item 2 since with a proper vacuuming there s/b minimal water vapor.

If you have a minor leak, that's a different problem.

As I understand things:
The drier can retain tiny amounts of moisture, but it's main function is to ensure that liquid refrigerant goes to the expansion valve, why it feeds from the bottom and gets installed pretty much vertically. I'd say that a larger-size drier "might" help if one is guessing at refrigerant level when filling. Modern AC systems are engineered to require only a small amount of refrigerant, so modern driers are small.

To me, small driers and thus critical refrigerant fill is the #1 reason why amount of refrigerant on modern systems is critical.

hi
R/drier will be ok a larger unit won`t hurt
Remember the system = 2.6 ton
Try and match compressor ,,evaporator txv from a known combo ,,Saves the guess work from having mismatched components
engine drive pulley diameter can be varied a little

Condenser size bigger the better . Remember to fit 2x 12 inch electric 15amp each wired to come on with compressor . No requirement to operate by psi switch
A good condenser setup
psi/temp does not vary idle to 1500rpm = good condenser size
On a very hot day 110+f psi should be stable
What does all this do?? This set up provides consistent low temperature liquid supply to R/drier and evaporator . The performance will be far better in hot weather as a result .