Degree Days: How They Figure Into Your Energy Calculations
At the end of every month, if you’re like a lot of homeowners, you look at your utility bills to see how much energy you have used over the course of the past month. In the winter and summer, the cost of heating and cooling your house will go up drastically. In order to calculate what your approximate monthly bill should be, you can keep track of the number of degree days that you are using within the current month.
What Is A Degree Day?
A degree day is a unit of measurement developed to help track your energy costs. It measures the amount of energy used to heat or cool your home depending on the season. There is a formula used to determine the number of degree days used. You take the average temperature for the day (if the high is 95 and the low is 75, the average temperature would be 85 degrees) and then subtract 65, which represents a settled-upon number for an average home’s most comfortable temperature. Given that example, this leaves you with 20 cooling degree days for that particular day.
In the winter, the formula works similarly. Rather than subtracting 65 degrees from the day’s average temperature, you subtract the average from 65 to calculate the number of heating degree days. For example: if the high and low for a December day are 35 and 15 degrees, your average is 25 degrees. You then subtract 25 from 65 to find that your home used 40 heating degree days on that day.
Benefits of Tracking
When you make the commitment to tracking your energy usage in this way, you can get a good estimation of what your monthly energy costs should be. If you know what you paid for using a certain amount of degree days last month, then by tracking your degree days this month, you will know if your bill will be more, less, or about the same as what you previously paid.
If you have any questions regarding efficient energy tracking or other HVAC issues, contact Ernst Heating & Cooling. We serve the Maryville area with pride.
Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems). For more information about how degree days figure in to your energy calculations and other HVAC topics, download our free Home Comfort Resource guide.
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