condenser subcooling

[claude11]

Does load affect condenser subcooling . I know a low condenser subcooling can mean low charge but I work with blast freezers , there is a intial big load and 16 - 20 hours later the load is small . would subcooling be different at the start , when there is a big load and increase as the load gets smaller or would it stay about the same

[BigJon3475]

If the the conditioned space is the same temps and outside temp increase....the gas will not condense as fast running through the coil.

[Tesla]

Yes - As the load drops off the subcooling will increase. Mainly due to the tev closing, reducing evap temp and press, this reduces the amount of refrigerant flow allowing more time to cool the condensing refrigerant.

[wambat]

Tesla is correct, as load deminishes so does the mass flow and condenser has more refrigerant

[claude11]

From what you guys are saying , to use condenser subcooling to check a possible low charge , there should be little or no load on the system ?

[paul_h]

No, you'd want full load, so it runs optimal when it's needed the most. Check motor amps too.
The reciever can take care of the excess refrigerant when there's low load.

[claude11]

Thanks Paul . 10 - 15 degrees subcooling at full load and the sub cooling will increase as the load decreases

[coolkid]

Hi Claude11

Is that in degrees F?

[claude11]

Is it's degrees F . ( half my equipment is canadian [metric] and half is American made [ standard units]

[Suta Eugen]

Does load affect condenser subcooling . I know a low condenser subcooling can mean low charge but I work with blast freezers , there is a intial big load and 16 - 20 hours later the load is small . would subcooling be different at the start , when there is a big load and increase as the load gets smaller or would it stay about the same
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About subcooling :

When subcooling the liquid refrigerant before it enters the expansion valve the purpose is twofold:
- to increase plant refrigeration capacity;
- to prevent flash gas formation ahead of the
expansion valve .
Condensed refrigerant can be subcooled in diferent ways :
- by dimensioning condensers in such a way that in addition to featuring the necesary condensing surface they also incorporate a subcooling section.In air cooled condensers however the achived effect is normaly insignificant .By expanding the condensig surface you can at best reduce the condensing pressure.
- by installing internal heat exchangers thereby providing subcooling and suction gas superheating at the same time.

A good value of subcooling is 3...6 of Celsius degrease.

Good luck

[Suta Eugen]

Does load affect condenser subcooling . I know a low condenser subcooling can mean low charge but I work with blast freezers , there is a intial big load and 16 - 20 hours later the load is small . would subcooling be different at the start , when there is a big load and increase as the load gets smaller or would it stay about the same

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If you have a good condensing control the subcooling it will by ,with small diferences ,the same.

[Yasser Khaldi]

Hi
can u provide the full readings and measurments u have.

[Peter_1]

A subcooler incoporated in the condensor coil is not that effective because if flows to the receiver where it will change to its saturated condition.
It's better to use an additional condensor mounted under the main condensor and where the liquid is coming from the receiver before it goes to the TEV's via an isolated liquid line.