Refrigeration 101

[eamonn493]

I first check the delta-T's to confirm adequate airflow through both coils.

Then I check for high subcooling.

Then I check for low superheat.

Then I check for low subcooling.

Then I check the condenser TD to see if the high side is rejecting a heavy heat load.

If the high side is rejecting a heavy load, then the low side must be absorbing a heavy load.

Adjusting a TXV aka TEV is almost always a mistake, especially when the refrigerated space is above design temp.

Hi Gary
Brilliant artical !!! Iam new to this A/C but I find it very interesting. One problem I do have is some of the Buss words you experienced engineers use.
eg delta T, TD. pulldown etc could you explain some of the more basic ones for me please. Also we had a leak on a compressed air cooling system last week all the 407 gas had been lost. repaired the leak and recharged every thing ok now,but noticed a bypass valve had been fitted to the system,how do I know if this valve is working?
One last point could I have lost some of the oil from the system,how do I check it.
Regards Eamonn

[nike123]

Hi Gary
Brilliant artical !!! Iam new to this A/C but I find it very interesting. One problem I do have is some of the Buss words you experienced engineers use.
eg delta T, TD. pulldown etc could you explain some of the more basic ones for me please. Also we had a leak on a compressed air cooling system last week all the 407 gas had been lost. repaired the leak and recharged every thing ok now,but noticed a bypass valve had been fitted to the system,how do I know if this valve is working?
One last point could I have lost some of the oil from the system,how do I check it.
Regards Eamonn

Delta t ( Δt) is difference between two temperatures of same media.
For example, air entering and leaving condenser, or air entering and leaving evaporator, or water entering and leaving condenser, or water entering and leaving evaporator.

TD is difference in temperature of two different media.
For example, difference between saturation evaporation temperature of refrigerant in evaporator and evaporator air entering temperature or difference between condenser air entering temperature and condensation saturation temperature.

http://www.refrigeration-engineer.co...75&postcount=5

Pull down is time period passed from starting equipment to reaching design condition.

For your problem please post question in new thread since that is not refrigeration 101.