Calculating
Heat Transfer The amount of heat loss depends on the geographical location of the building. More heat will be lost from a cabin built in a cold climate such as Fairbanks, AK than from a structure in a warm area such as Phoenix, AZ. The rate of heat loss is calculated my multiplying the heat transfer coefficient (U) by the heat index (HI) of the location of interest.
1.) Determine the HI for the location. HI is in units of degree days per year. Heating degree days are determined by subtracting the average temperature for each day over a year from 65 degrees Fahrenheit and summing the results. This is only done for days when the temperature is less than 65 degrees Fahrenheit. If it is warmer than 65 degrees, it is assumed that heating is not necessary.
3.) Find Q using the U value obtained above
This value is the average amount of energy that will be lost through a square foot of wall in a year.
