R410a Discharge Temperature

Tom Blackwell_2

Typical can compressors operate with 50-100 degrees of superheat with 410-a. The reason there are so many desuperheater dissapointments is in the design of the system. As we all know, you can't transfer btu's unless there is a temperature difference, so trying to add heat to a tank full of 140 degree water doesn't work. The solution is to preheat cold water and use it as make-up for the water heater. My geothermal system is set up in this manner using a standard 40 gallon water heater as a preheat tank. A circulating pump pumps a loop to this tank and the tank outlet feeds the service water heater. The preheat tank ranges from 95 degrees to 125 degrees, depending on the heat pump operating hours; inlet temperature is 60 degrees. I have seen many systems plumbed up with no circulator so there is only heat transfer when the unit is operating and there is a draw of hot water! Go figure...

The Wire Nut

R410a Discharge Temperature

Hey Professor!

I am contemplating desuperating the two condensers I own... question is, what is a typical discharge temperature for a R410a compressor? I'd like to try and pencil out any savings before I take the leap, so any insights you have into desuperating with R410a would be appreciated!

Cheers!

Brad White

Here is

a chart you may find helpful Constantin. I am not sure what specific head pressure is developed but the chart tops out at almost 614 PSIG and that corresponds to 150 F saturated. I understand that the mid 400's are normal high pressures. Remember these are all saturated temperatures. The amount of superheat is unknown to me.

I will sit back and learn something today.

Brad

Nick S

Well I can't help you on the discharge temps, but I can give you some in put on the desuperheating. I assume you are going to do this to suppliment your domestic hot water?
I have installed a 4 ton climatemaster geothermal heat pump with a desuperheater, and in my opinion (and the homeowner's) it is a waste. This is in a home, so the loads are not real high. I think we are in the 600 cooling hours per year range, maybe an office building would be a different story. Also, I toured the American Standard/Trane ac plant in Tyler, Texas last year. One of the employees we talked to said they were working on this years ago, but they found there was no real benifit in a residential application, even in Texas. Now, this is just my experience, and what I have heard. Maybe someone else will be able to give you more advice.

Techman

Dis Temps

You can still get a nasty burn on your arm,ow!The evap superheat is the same,the s/h at the comp is the same,the subcooling thru the cond unit is the same[seer vs. seer]and liquid line temps going into the evap are the same. And the P/T or T/P saturated condensing temps are the same.So,I would assume the dis line superheat temps are also the same.But don't quote me on that!