hvac-lv
07-17-2006, 07:33 PM
Ok,
Got a 2.5T unit, split is only around 13 deg. Outside it's +/-107F. Suction PSI = 70.5/Head PSI= 312. Pressures have not changed for over 30 mins.
Pressures seem good, but a noticeable lack of cooling inside supply = 80f & return right above coils = 64f. Even on cooler days (90-100) the unit can't keep up with the heat load and never satisfies. I had a company come out to get a 2nd opinion on things and they saw the evap coil was fouled more than a bit and they think that's the problem. I can see that, but the motor amp draw is low and it hesitates on start up a bit, so it might be that as well. In addition to all that, the install is roughed in, and I mean roughed. The supply intake is an erratic size (14x30), but the actual area where the air is drawn in is cut in half because of the plywood that the air handler is resting on, so the effective open area that air has to come into the evap coil is about 14x15, I think this might be why the suction side always seems a bit low, even though the high side is OK and why the unit doesn't seem to be cooling adequately.
Overall, I think this might be an airflow issue, what do you guys think? Oh, and this is a split system.
[Edited by hvac-lv on 07-17-2006 at 07:38 PM]
Got a 2.5T unit, split is only around 13 deg. Outside it's +/-107F. Suction PSI = 70.5/Head PSI= 312. Pressures have not changed for over 30 mins.
Pressures seem good, but a noticeable lack of cooling inside supply = 80f & return right above coils = 64f. Even on cooler days (90-100) the unit can't keep up with the heat load and never satisfies. I had a company come out to get a 2nd opinion on things and they saw the evap coil was fouled more than a bit and they think that's the problem. I can see that, but the motor amp draw is low and it hesitates on start up a bit, so it might be that as well. In addition to all that, the install is roughed in, and I mean roughed. The supply intake is an erratic size (14x30), but the actual area where the air is drawn in is cut in half because of the plywood that the air handler is resting on, so the effective open area that air has to come into the evap coil is about 14x15, I think this might be why the suction side always seems a bit low, even though the high side is OK and why the unit doesn't seem to be cooling adequately.
Overall, I think this might be an airflow issue, what do you guys think? Oh, and this is a split system.
[Edited by hvac-lv on 07-17-2006 at 07:38 PM]