How to Calculate Heat Loss in a Steel Mill

The easiest method for discovering the amount of heat loss you'll experience in a year at your steel mill is called the degree-day method. The degree-day method is based off an average of 65 degree days. For every degree that is not 65 degrees in a 24-hour period, a degree-day is created. For example, if the average temperature in a 24-hour day is 60 degrees, there will be 5 degree days attributed to that 24-hour day.

Instructions

1. Take the design heat loss in BTUs (British Thermal Units) and multiply it by 24.

2. Multiply the sum of Step 1 by the total number of degree days in a season. Remember that a degree-day is not a representation of one 24-hour period, but the number of degrees below 65 degrees.

3. Divide the sum of Step 2 by the design temperature difference between the indoor and outdoor temperatures of the mill. Many buildings have an indoor temperature between 55 and 68 degrees, but you should use whatever the indoor temperature of your mill is.

4. If you prefer to use an online calculator or if you are unsure of the design outdoor temperature of your area, see "Resources" below for a link to a calculator.

Tips & Warnings

• When calculating degree-days, use the mean of the daily temperature.

Resources

• About degree days
• Degree day calculator