house not cooling well

[themayor]

I just got new a/c unit installed to replace the one that was working fine but getting old at 15 yrs. They are both the same seer ratings.Problem is, the new unit runs almost constantly. It is 89 dgrees here with 47 0/0 humidity. The air out of the rgisters is 59 degrees. The suction lines is cold, wet and dripping. I have some gauges and I put them on today when it was 90 degrees outside. The low side was reading about 75 p.si. the high side was reading 250 psi.

All conditions in the house have remained the same. Such as windows and blinds closed etc. Anyone know why the new unit is not working as good as the old one.

Thanks.

[hiltontech]

Your pressures are really good, 59 temp coming out of the register is very good also,when you say it runs constantly do mean it never turns off or does it turn off when the outside temp drops during the evening.
What is the temp inside your house right now?
If you set your thermostat to say 72 will the unit bring the temp down to 72 and then turn off? or does it not bring the temp down at all?


Let us know.

HiltonTech

[themayor]

Yes, it will turn off when it cools down outside in the evening but during the day I can set the Tstat at 78 - 80 and it will run constantly. And in the evening it does cool down pretty good. I know a little about A/C units as I have several rentals and have my EPA card but don't know enough to figure this one out.

[TigerDunes]

themayor

The old unit just replaced cycled on/off at the 90 deg+ temps? Conditions have not changed except for condenser unit? Was air handler also replaced?Air flow speed the same? What size was the old unit? New unit same size?
What size is your home?

:thinker:

[themayor]

yes, the old unit cycled on and off at the 90 degree + temps. Nothing else has changed, air handler, a/c size. Both units are 3.5 ton with same seer ratings.

Thanks

[hvac guy]

Is your fan set on the on setting at the t stat ?

[themayor]

Is your fan set on the on setting at the t stat ?

no, the fan switch is as it should be, the unit shuts down when it gets to set point, which doesnt happen when it is over 90 outside.

[hiltontech]

I have somewhat of the same problem here at my home, the a\c runs to much during the day, I know the problem which is a dirty "A" coil which I haven't the time right now to clean it out being I have to much work going on right now, hopefully I will see about my own unit soon.

Hiltontech

[themayor]

My A coil wasn"t very dirty, but cleaned it anyway, same story! I was wondering if it could be the officice at the A coil?

[Ed Imeduc]

My A coil wasn"t very dirty, but cleaned it anyway, same story! I was wondering if it could be the officice at the A coil?
Now is this the old A coil thats still 15 years old???If so it could be a seer of 8 and you say the inside and out have the same seer here??? Dont see how. But why didnt you get a unit for inside on out with a seer of 12 or more this day and age. Can be the orifice but think coil dont match the new compressor.

ED ;)

[themayor]

The old unit was 10 seer and the new one is a 10 seer.