A/C mystery. House Inspector vs. HVAC tech - http://www.hvacmechanic.com/ Forums

Original message

Travis 65

97.95.130.203

"A/C mystery. House Inspector vs. HVAC tech" , posted Mon 2 Jun 21:52

We recently sold our home and a home inspector came to the house. When he checked the return air temp and the vent air temp there was a problem. The air gong in was 72 degrees the air coming out of the vents was 68. We just had a new coil put in and he said to call the service tech. When they came, he measured the temp and it was 72 going in and 55 coming out. He said the system was working normally and blamed the house inspectors thermometer. This confused me, so I have been monitoring the temp ever since. I have noticed that the thermostat will kick on the A/C unit and the temp difference will only be a few degrees as if the unit isn't cooling. Then maybe 20 minutes later the lights will dim just briefly when the system "engages?" After that, the temp drops from the vent 15 degrees and the house cools in 30 minutes. 1. Why does the fan run and the air coming out is less than cool even though the thermostat has engaged the system? 2. Why does it take so long to engage cool air once the fan is on? 3. Is this normal?

Replies:

Houston204

98.196.66.53

"Re(1):A/C mystery. House Inspector vs. HVAC " , posted Mon 2 Jun 22:33

It sounds as if your compressor is having trouble starting. A starting assist or a 5 minute timer may help.

Do you have a digital stat? They usually have a 5 minute timer which protects the compressor from short cycling.

On another note...
Did the home inspector use an infrared thermometer? Those things do not accurately measure delta tee. They measure surface temperature not air temp.

"Tip of the Day" Remember to remove power first.

Travis 65

97.95.130.203

"Re(2):A/C mystery. House Inspector vs. HVAC" , posted Tue 3 Jun 07:30

I do not have a digital stat. Yes he did use a infrared thermometer, I knew that it was off, especially when he took the temp of the vent air in front of an window with sun shining through. If it is the compressor, does this signal the end is in sight?

Houston204

98.196.66.53

"Re(3):A/C mystery. House Inspector vs. HVAC" , posted Tue 3 Jun 07:40

It may only need a timer or a hard start kit.

Most digital stats have a built in timer.

"Tip of the Day" Remember to remove power first.

Travis 65

65.1.109.20

"Re(4):A/C mystery. House Inspector vs. HVAC" , posted Tue 3 Jun 13:34

Do you know the estimated cost?

Houston204

98.196.66.53

"Re(5):A/C mystery. House Inspector vs. HVAC" , posted Thu 5 Jun 23:50

$229 for an 011

"Tip of the Day" Remember to remove power first.