AC --- geez

Apr 04, 2007 5 Replies

Our house ac compressor was replaced today. The guys sold me a SER13 3.5 ton American Standard to replace a 3.5 ton Carrier about 10 years old. The new unit is much bigger. Someone told me that it wasn't good to replace a 10 SER with a 13 SER because the coil would have to be replaced and at least the orifices would need work/ or was it replacement. But he said that if the installers knew what they were doing, he would guess that they could make it work.



The AC has been running for 5 hours and won't cool below 75 degrees on a pretty cool day. Google says it's 84F now here in the desert.



Is an orifice or coil problem going to show us as an inability to cool or do good readings on the guages outside on a ground level of a split A/C furnace tell the installer everything he needs to know? Any ideas what might be wrong? He's comming back later today and I want to be able to ask a few good questions, if possible.


My mother had her 20 yr old a/c unit in Florida replaced and the new unit was also much larger. Installer said that all the newer non-freon designs were bigger units. I dunno.

The number one thing you need to find out is the temperature of the air coming out of the registers. If it's 60 degF or less, then your problem is more than likely air flow related (clogged filter, open pipe in the attic, dirty fins, etc., etc.). If the air temp is in the upper 60's or warmer then the problem is likely related to your new compressor and/or its installation.

That really makes sense. Thanks

Actually, it's a 20deg differential. If 100degree air is going in, the output may be 80. If 80 degrees ambient, then 60 degrees output is okay.

This is not quite correct. The temp difference is 15 to 20 degrees from supply to return. This is not a definative test but does give an idea of what is going on.

Also the moisture in the house determines the temp drop. That's one of the reasons to leave the AC on 24 hours.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required