Overcharge Question

WoodBurner · 07-19-21, 11:20 AM

If the extra refrigerant just ends up in the receiver, could you make a bigger receiver and have a system that is not sensitive to overcharging?

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MN Renovator · 07-20-21, 07:55 PM

For a vehicle application with a combustion engine, usually the compressor speed isn't controlled by the anything other than whatever the engine speed is and pressure switches turn things on and off instead of everything running at a fixed speed in a critically charged home system. The receiver also allows a bit of long term very slow leakage allowance that generally occurs in a system with a shaft seal. It gives a little bit of leeway for refrigerant quantity, but I think it impacts efficiency if it isn't right where it should be. In either case there will be a point where the system will be overcharged or undercharged, so I'm not really sure if I know how to answer the question you are asking.

Basics about this
https://hvacrschool.com/receiver-basics/

jeff5may · 07-26-21, 09:12 AM

It depends on the system. Lots of ifs and measurements to verify, like in the picture. The main idea is that there's little to no subcooling in the condenser side of the system when a liquid receiver is used. This is a lot more important in an expansion valve metered system than a cap tube system.

07-19-21, 11:20 AM	#1
WoodBurner Lurking Renovator Join Date: Oct 2018 Location: MD Posts: 6 Thanks: 19 Thanked 2 Times in 2 Posts	Overcharge Question If the extra refrigerant just ends up in the receiver, could you make a bigger receiver and have a system that is not sensitive to overcharging? g Attached Thumbnails Last edited by WoodBurner; 07-19-21 at 11:33 AM.. Reason: made picture bigger

07-20-21, 07:55 PM	#2
MN Renovator Less usage=Cheaper bills Join Date: Nov 2010 Location: Minneapolis, MN Posts: 940 Thanks: 41 Thanked 117 Times in 91 Posts	For a vehicle application with a combustion engine, usually the compressor speed isn't controlled by the anything other than whatever the engine speed is and pressure switches turn things on and off instead of everything running at a fixed speed in a critically charged home system. The receiver also allows a bit of long term very slow leakage allowance that generally occurs in a system with a shaft seal. It gives a little bit of leeway for refrigerant quantity, but I think it impacts efficiency if it isn't right where it should be. In either case there will be a point where the system will be overcharged or undercharged, so I'm not really sure if I know how to answer the question you are asking. Basics about this https://hvacrschool.com/receiver-basics/

07-26-21, 09:12 AM	#3
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,431 Thanks: 431 Thanked 619 Times in 517 Posts	It depends on the system. Lots of ifs and measurements to verify, like in the picture. The main idea is that there's little to no subcooling in the condenser side of the system when a liquid receiver is used. This is a lot more important in an expansion valve metered system than a cap tube system.