Defrost Suggestions for Gravity Coolers

[Brian_UK]

Recently been given a site with a Frigadon (FWC 2000) 4 compressor water chiller running R1270 and Hycool brine solution. Brine temperature is -7°C.

The gravity coolers are in a large cool room, fish market, and also a cold store. The main areas are open to ambient conditions due to roller shutter loading doors and the cold store is inside this area. Not sure about the required cold room temperature but probably around +10°C (?); the cold room runs at +4°C I believe. (Got more reading to do to catch up with this site.)

The present defrost has been set for a one off period of 1.5 hours which is allowing the room temperature to rise too much.

I haven't worked with gravity coolers before and as yet haven't seen these ones running under load so don't know what the coils look like after a cooling period.

Would a single defrost period normally be sufficient or would several periods be better for the the system.

Any advice welcomed.

[frank]

Not something I'm familiar with Brian, but, is the defrost period at the end of the days trading?

I can see the logic in having the system run all day if trading is taking place, and then defrosting when closed to prepare for the next day. But, as you say, you need to look at the system a little closer before making any decisions.

[Brian_UK]

End of day would make sense but I am told that the defrost time is 10:30 'til 12:00; the tricky thing is that I don't know whether they use the 24 hour clock or not.

Also, being a harbourside fish market they could be unloading at anytime day or night. A suggested time to me was 00:01 hrs to 01:00 hrs. Anyway it's the first call tomorrow so we'll see what's happening. If nothing else, we'll keep the harbour master happy by turning up.