I bought an infrared thermometer to help do my own energy audit. The camera is simple enough to use. You just point the beam at something (walls, ceiling, floor, etc) and it tells you the surface temperature.
The problem I have is I don't know what the temperature SHOULD be. I've got a brick bungalow in Michigan built in the 50s. I use a digital thermostat set for 72 when I'm home and 65 when I'm not in the winter.
Assume I have adequate insulation in the walls and crawlspace. What temperature should the walls and ceiling be when I'm home? Right now they range from 65-68 degrees. Is that good or bad?