I am working on a two stage heat pump with a varable speed air handler.
The system runs about 1.5 deg S/C and about 2 deg S/H The delta T is 22 deg. A capacity check shows systems is operation at 122% of publish Capacity. Adding refregerant does not change the S/C much at all.
My question is how is this possable? low subcooling and low S/H
This is a matched system, and all test equiment was checked for accuarcy.
Originally Posted by skidoox800
TXV Problem, Airflow is good at 700 CFM for a 2 ton. Newer systems call 350 CFM better dehumidification. Seems stuck open.
the only way he's getting 122% rated capacity is that there is actually less airflow than the number he used in the capacity calculation.
my boss thinks its possible to repeal the laws of physics
I believe your compressor is still in first stage. IIRC there's a five minute delay from signal sent to compressor engage in addition to the delays in some thermostats. I've seen those same pressure/temp/sh/sc conditions on a carrier two stage system that would not engage full capacity.
Sorry for the delaying in posting, While I was on vacation, another tech replaced the indoor coil. After replacement the system ran at spec's 12 deg s/c 9 deg of s/h. althought the coil would frost evenly when the blower was off. We ran out of options and replaced the coil. I am requesting an RMA back to Carrier to have the coil tested. If I get anything back I'll post thier finding.