Hot gas defrost in commercial refrigeration 2

[19730206]

Hello, experts
I'm looking for information about hot gas defrost system.
I know some theory, but never seen real system.
It would be great to see working system photo.
Has anyone tried an hot gas defrost system for low temperature islands, how did it work out?
What world's manufacturers use it?
What advantages and disadvantages hot gas defrost system in comparison electrical defrost system?
Thanks for any advance or link.

 

[imok2]

GO here:

http://www.trane.com/Commercial/Dna/View.aspx?i=553

Click on hot gass bypass

 

[gepman]

I think that imok2 has gotten hot gas bypass compressor capacity modulation confused with hot gas defrost which is used to remove ice from evaporator coils.

I don't have much experience in commercial refrigeration but in industrial refrigeration hot gas defrost is used in over 90% of the applications that I have seen where coil icing occurs. Experienced industrial refrigeration engineers have no problem with hot gas defrost working well it just takes proper valving, coil setup, and valve sequencing.

The only problems that I have seen is sometimes too many coils try to defrost at one time which will lower the discharge pressure to below acceptable limits. Some facilities with floating head pressure controls raise their head pressure setpoint just prior to defrosting a coil.

You can check out the following link:

http://www.heatcraftrpd.com/resources/brochure/H-HGDSB-0307-000.pdf

 

[imok2]

Opps my bad, thanks for the correction gepman (