grille temperature - http://www.hvacmechanic.com/ Forums

Original message

dproof

69.161.162.167

"grille temperature" , posted Sat 19 Jun 15:04

I had a house inspector check my house. He pointed a beam to the grille on the ceiling and told me that I should have my ac unit checked ( he also checked the temperature coming out of the ouside fan).
What temperature should I have coming of the grille? Outside fan?
Thank you.

Replies:

HVAC Doc

64.123.113.178

"Re(1):grille temperature" , posted Sat 19 Jun 15:47:

Infrared thermometers are nice, but can be deceiving. Use a probe type thermometer and measure the supply temperature and then measure as close to the furnace/airhandler the incoming (return air) temperature. Generally you want an 18-22 degree temp difference between supply and return. That though depends on several other variables such as system setup but it will give you a place to start. To low a difference in temp means either the air is going too fast across the coil and not removing enough heat or could have a problem with under/overcharge. Too high a difference means not enough airflow either a dirty air filter or blower wheel, a dirty evaporator coil, not enough return, or system low on charge.

[this message was edited by HVAC Doc on Sat 19 Jun 15:47]