***** hot gas defrost

[COLD WANG]

who has some experience with hot gas defrost in ***** system .
one compressor, one aircooler ,and a watercooled condensor,
how can i do it? in winter how can hot gas defrosted?
cood room temp is -28dec.
when defrosted the aircooler,the water in the condensor will become ice?and the oil in the condensor can return?
if the condenser is aircooled ,its no problem?

[Peter_1]

It all depends on the waterflow through the condensor, it can work.
How is teh waterflow in normal conditions regulated?
Why you want to change it to hotgas defrost?
Are you not making a setup more prone to failure?
Just my vision on this.

[MikeySq]

How can you do it? If you have one evaporator and you try to put it in to hot gas defrost where are getting a refrigerating load to produce hot gas from if your only evaporator is being defrosted?

Or did i read this wrong are you trying to make a hot gas bypas to the evaporator in order to keep the SST above freezing??

I guess I'm not totally understanding the application, first post on here bare with me, lol
-Mike

[The Viking]

First of all, the driptray and the condensate drain needs to be heated (with electrical heater in some shape or form, heated cable as used for trace heating applications are, normally, easy to install).

The hotgas defrost cycle itself;
In old-fashioned commercial freezers, you simply had a line from the discharge to after the expansion device with a solenoid valve in it. When it came to defrost, first the solenoid in the hotgas line would be opened, then a minute or so later the compressor would stop. After the defrost cycle ended the hotgas solenoid would be shut and the compressor restarted.

Worked well in both industrial and supermarket applications.

[taz24]

I guess I'm not totally understanding the application, first post on here bare with me, lol
-Mike

As the winged helmeted norsman says it is common practice, or was untill reciently in the comercial sector. Inject the discharge straight from the comp to a point after the TEV but before the evap coil. The coil defrosts instantly and the gas returns down the suction back to the comp. It can only be done for a short time due to the increased superheated gas returning to the comp.

Cheers taz.