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WootAC??
27-08-2013, 12:44 PM
Hey

I am working on a project in which we have an ambient temperature on 55 degree celsius, and most of the compressors that are out there will only be able to deliver a condensing temperature of 60 degree celcius, will this be enough for the heat to flow from the condenser to the ambient air?

Normally i would of course go for 10-15 degree celcius higher than the ambient, but since this application probably will be used in desert/jungle environment such high ambient temperatures is to be expected !


Regards
Michell

desA
27-08-2013, 02:20 PM
You will find that the power used, may very well affect the allowable Tc,sat (condensing temp) allowed for the compressor.

We've seen the US version rated closer to 62.5'C (at 110V), while the European/UK/South Africa/Australia version could run up to 70-75'C. (Refer back to a thread by Gary & myself, some years ago, where we discussed this).

Heat-pump compressors can run hotter than standard refrigeration systems. In the end though, your overall COP will be poor.

You may have to pull a few more technical tricks to achieve your end goal.

The Viking
27-08-2013, 03:06 PM
most of the compressors that are out there will only be able to deliver a condensing temperature of 60 degree Celsius

Appels and pears...

The compressor doesn't know what the actual condensing temperature is, and it doesn't even care as long as it itself is cool enough.
The data you will have to look for is the maximum operating discharge pressure and then select the refrigerant accordingly. When you look at the data sheets for the compressors they will only tell you the "optimum design envelope" as when you go outside this the performance drop quite significantly but this is not to say that the compressor won't operate outside these conditions.

You might have to add liquid injection to the suction line to keep the compressor and the oil cool enough but as long as you keep below maximum discharge pressure the compressor should keep on pumping.

:cool:

WootAC??
28-08-2013, 01:43 PM
I was actually just hoping for an yes or no answer, but I will look into the informations given :-)


Regards
Michell

desA
29-08-2013, 09:14 AM
Precious few yes/no answers in the RHVAC game. A world of balanced options.

fridgey
29-08-2013, 12:46 PM
Yes it can be done, R134a would probably be the optimum refrigerant and the condeser sized on a low TD.

mad fridgie
29-08-2013, 12:56 PM
Copeland Scroll max SCT 75C and 0C SST on R134a. No issue with your 55C ambient

WootAC??
29-08-2013, 01:36 PM
Thanks for the answers :-)


Regards
Michell