View Full Version : subcooling with txv
05-18-2006, 08:26 PM
Installed a Goodman 3 1/2 ton condensing unit with a 5 ton evap coil in a variable speed air handler. Package system is suppose to be 15 seer. I have 10 degrees of superheat at the condenser which is the design point for this system with a txv. Suction pressure measures 82 psi and liquid line measures 200 psi with an outdoor temperature of 100 degrees. It calls for the air handler to be charged to 15 degrees of subcooling at indoor inlet. The best I can get is 10 degrees. Is there a problem or do these new seer units have higher suction pressures.
05-18-2006, 09:01 PM
TXV sensing bulb has not been properly located and installed.....blower has not been properly set up for 3.5 ton of cooling.
05-18-2006, 09:13 PM
Originally posted by justhanging
I have 10 degrees of superheat at the condenser which is the design point for this system with a txv.
Guess I am the only one that was taught to check SC only with TXV but hey I am subject to change one day when I can be convinced to check SH with a TXV that it matters but as of now I haven't. :D
I just always thought that SC was more important because you needed a certain amount of SC to maintain a constant pressure at TXV, but who knows, I have just never really concerned myself with SH on a TXV system, I have always done it the SC method and it's always worked out for me just fine.
05-18-2006, 09:42 PM
you always check both SC and SH to be sure you have a properly mounted TXV bulb. And you can see the whole picture as far as the freon circuit. If it is not located correctly or tighted with a good metal strap, you will have a good SC and flood the compressor at the same time.
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