PDA

View Full Version : Remote Condenser Sizing







Goober
17-11-2015, 02:48 AM
Gents,

Your opinion please. When engineering a new remote condenser, how would you size it?

Currently I've been educated to first select my compressors at design conditions, say at -25C SST/45C SCT, which for this exercise we will pick a compressor capable of 100kW cooling capacity, with 145kW THR.

I now use the previously selected compressor and change the SST from -25C to -5C. Then, using the increased THR of say 165kW resulting from the new SST to select my condenser.

The theory being that condenser will more than cope with the recovery involved in a total plant failure or after excessive defrosts. But then be oversized, but costly for initial install, when operating at design conditions.

Thoughts?

RANGER1
17-11-2015, 08:38 AM
I'm no design engineer, but sometimes in the condenser selection it may be borderline on one size, so this can help make decision.
Client, if a good educated one can be given both selections as well, but not in all cases.
Maybe go I between what you think & say -10 to 15 C SST & see what it comes up with.
Rooms should recover pretty quickly after defrost unless abused.

chemi-cool
17-11-2015, 02:44 PM
From my experience in a hot ambient, after working out the condenser capacity needed, I choose the next size so unit can cope with the problems you have mentioned.

One stem bigger is not a big difference in price and unite will work better.

Magoo
17-11-2015, 09:27 PM
Goober.
I usually select capacity at -10'C SST for condenser selection and use MOP TXV's as well to limit load on compressor after defrost .

Goober
19-11-2015, 03:32 AM
Cheers all. Seems we are in a agreement. I shall power on doing what I'm doing then.