What should the temperature of air from the heat vents be?

Answer 1

Automobiles:

COLD TO HOT or if you want to be technical between 62+- to 92 +- Fahrenheit on average. if its too cold the heater obviously isn't working, but may I suggest first looking at your heater controls to ensure the temperature dial is set to warm (THE RED PART OF THE CONTROL)

Homes:

When trying to cool a typical house, the average central AC will only decrease the temperature by about 20 degrees. For example, when it is 100 degrees outside, the inside will typically cool to about 80 at best. However, in order to achieve the 80 degrees inside, the air coming out of the vent should be 45-55 degrees.

The temperature coming directly out of the vent is different than the ambient temperature of the house. The air coming directly from the vent should be 45-55, however this will not be the temperature in your home.

If using a thermometer stuck in the vent, and the blower fan on a medium speed, in the full cold position with AC on vent, temperatures should be between 40-50 degrees F. In the full heat position vent temps should be at least 140 degrees F.