# heating load

### Three Types of Heating and Cooling Loads

What is it about the number three? You've got the Three Musketeers, the Three Little Pigs, and the Three Stooges. Then there's three strikes (what every pitcher wants), three branches of government (executive, legislative, and judicial), and the three kinds of people (those who can do math and those who can't). And let's not forget three on a match, three wise men, and threepeats. Today we'll look at another big three: the three types of heating and cooling loads. Do you know what they are already?

### When Do I Need to Perform a Load Calculation?

In my last three blogs, I discussed the basics of heat-loss and cooling load calculations. The unfortunate truth about these calculations is that fast methods aren’t particularly accurate, and accurate methods require making measurements, checking specifications, and entering data into a computer program — in other words, a significant investment of time. So how should builders go about making these calculations?

### How to Perform a Heat-Loss Calculation — Part 2

To continue last week’s discussion of heat-loss calculation methods, let’s consider a simple rectangular building, 20 feet by 30 feet, with 8-foot ceilings. Let’s assume it has an 8-foot-high basement with uninsulated concrete walls; the below-grade portion of the basement is 7 feet high, with 1 foot above grade. To keep things simple, we’ll assume that the house has a flat roof, and that each side of the house has two windows (each 3 ft. by 4 ft.) and one door (3 ft. by 7 ft.). The house doesn’t have a chimney.