Originally Posted by
Kevin O'Connell
In Refrigeration and Air Conditioning Technology, 5E it states that based off of the return air temp to the suppy air temp should drop 20 degrees as it crosses over the evap coil. ie.. if you have a RA of 75 your SA should be 55 if you are at 50% relitive humidity. humidity will affect the reading,
That starts to get into better information, but ...
when we look for the 18 to 21 degrees of delta t (temp drop) that gives us a snap shot of how the system is operating.
No it does not. Not based on what you just stated.
You need to do dry bulb and wet bulb temperatures then chart it out, just as David said.