liquid reciever

[joe demo]

changing out an old water cooled condenser. 40 ton system . question old condensing unit has a liquid recieversetting in the sump of unit. new condensing unit does not have a reciever. manufacture says this is an exact change out .old unit may be 30+ years old. why the reciever. what would happen with out it. whats the reason for the reciever? thanks..joe

[lana]

Hi Joe,

As you know TEV responds to the superheat and therefore, closes or opens. When TEV closes then excess refrigerant needs a place. This place is the receiver. If receiver is not used then excess refrigerant will collect in the condenser. For air cooled condensers this is not advisable because the surface area is wasted and might effect the condensing process. On the other hand without receiver the refrigerant charge would be critical (like cap tube systems).

For water cooled condensers (relatively big ones) the bottom portion of the condenser acts as a receiver and you may not use a separate receiver.

Hope this helps
Cheers

[TXiceman]

A system w/o a receiver is typically called a critical charge system. The receiver can be a through flow or a surge type. The receiver can also be an operating receiver to handle only the system variations such as Lana describes or with an air cooled system with winter low ambient or flood back controls, it will store the extra winter flooding charge. It can also be sized to contain the whole pump down charge, which is typical of large industrial systems. The ASHRAE handbooks have a good discussion on receivers.
Ken