How do heating degree days work?

thermometerIf you are a Poore’s automatic propane or heating oil delivery customer, you probably know that your delivery schedule is based on a series of estimates.

The first of those estimates takes into account how much fuel you have used in past years (or, if you have recently become a Poore’s customer, an estimate of usage for a home your size in our Delmarva service area). The second estimate takes into account the current weather using a unit of measure called a heating degree day.

So what exactly is a heating degree day?

A heating degree day (HDD) is a number that is used to express how much energy is needed to heat a home or building. You can calculate HDDs by subtracting the average temperature of a given day from 65o F, which is the temperature below which heat is needed; every degree that a day’s average temperature is below 65o F is considered one HDD. Here’s an example: if the average temperature for a given day is 50o F, its HDD number is 15 (65 – 50 = 15).

Our software keeps track of heating degree days so we can have some idea of how much heating oil or propane you are likely to use.

Of course, neither heating degree days nor past usage can give us a precise measure of how much fuel you’re using; many other factors come into play, including:

  • How efficient your home is
  • How efficient your furnace or boiler is
  • How well your heating system was installed, and how well it has been maintained
  • How effectively you use your thermostat
  • How you choose to live in your space
  • And more

For this reason, if you are an automatic delivery customer, it is important to keep us in the loop if anything in your lifestyle changes that might affect how much fuel you’re using. For example, if you have built an addition to your home without changing your home heating system, you will naturally use more fuel – or if a person with a lower tolerance for cold has moved out of your house (an elder, for example), you might use less. Either way, let us know!

For reliable Delmarva propane delivery and heating oil deliveries, no one beats the pros at Poore’s. Contact us to switch to FREE Automatic Delivery or to schedule a fuel top-off today!