Ac Temp

Anyone have a general temperature that they look for at the registers when running a Central Air Conditioning system?

Look at the temperature differential between the supply register closest to the air handler and the return register. Should be about 15 degrees after about 10 - 15 minutes.

Dwight, Do you live in northern or southern CA?

The 15 degrees will differ depending where you are inspecting.

Look at B. Kelly’s link.

About 45 miles east of San Francisco. The climate here is moderate, but will get into the 90s in summer time. 1/3 the times during the year, it’s under 65 and I bypass the AC inspection.

Well I guess what Im saying is I shoot the registers with my temp meter and yesterday the temperature at the registers was about 70, usually Im at about 62 and below… Seemed high to me and that temp did not cool the house down.

Check the filter and intake plenum to see how dirty it is. 8 out of 10 times the filters haven’t been changed in a millienum and the filters are completely plugged up.

What can happen is that the air handler sucks on the plugged filter and pulls it up against it. When that occurs, the air handler is sucking dirt and dust into the system and depositing on the evaporator coil and everything else. When the coil gets covered with dust, it loses its efficency dramatically.

Another possibility is that the system has lose its refrigerant charge.

Neverthe less, recommend a followup examination of the furnace and air handler by a qualified HVAC technician. The charge for that type of service is usually somewhere between $200 and $300. The $100 or less specials you see advertised are a means for the HVAC guy to get inside the front door and do a sales pitch.