What should the air temperature be coming out of the registers?
Depending on the outdoor temperatures and humidity level, this number will fluctuate. The general rule is: 18 to 22 degrees below the outdoor temperature on a warm, dry day. For instance; if the outdoor temperature is 80 degrees with little humidity, the temperature of the air coming into your home will be 58-62 degrees. On mild day with outdoor temperature in the low 70’s or a very humid day the temperature may only be 15 to 17 degrees cooler.