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08-27-2009, 08:58 PM #1Regular Guest
- Join Date
- Jun 2009
New Condenser, Old Evaporator, functioning data
I finally had a tech adjust the freon charge in my Frankenstein 5 Ton 13 SEER New Nordyne condenser with 5 ton 31 year old evaporator using TXV.
There was a LOT of debate on this site about the merits, and efficiency/inefficiency of such a system.
I had the charge adjusted, and got the tech to write down all the numbers.
Here's what he got:
High Side, 223psi, (108 *F), measured temperature 99.5 *F
SC= 8.5 *F
Low Side 70-72 psi (38- 39 *F) cycles every 30-60 seconds, measured temp 63.7 *F
SH = 24.7 to 25.7.
Because of the TXV he charged to the chart provided by Nordyne for TXV. It calls for a about 9 *F SC at 225 Liquid Pressure.
The outdoor temp was 90*F.
Static pressure air handler, 0.65 inch.
(Manual says 0.50 inch MAX.)
Chart suggests at 0.65 inch water, about 1855 CFM.
Indoor Return 76 *F DB, 66 *F WB
Vent 57.5*F DB, 55.2*F WB.
Delta DB = 18.5 *F
The superheat seems high. I asked him if he could adjust the TXV. He said because of the way the evaporator was installed in the attic, it will be difficult to access the valve. (Plus not sure about the wisdom of adjusting a 31 year old part!)
Would you recommend adjusting the TXV to get superheat lower?
I have budgeted to replace the indoor coil and air handler before next summer's cooling season. Do you think I will be OK with the above operating conditions for the rest of the summer in Dallas Texas?