It is worrisome for many homeowners when they realize their heat pump is running all the time. If you live in Central Indiana, or any state with weather similar to Indiana, then you are familiar with your electric heat pump running non-stop on the cold days. If this concerns you, then perhaps your heating contractor is not a heat pump specialist. A heat pump specialist will explain to you the truth: your heat pump is a very efficient means of heating your home and it is designed to run 24/7 during the cold days and nights. Here is the honest science, compliments of Precision Comfort Systems in Westfield, Indiana, your heat pump specialist for all the Indianapolis area.
Unlike a conventional gas, oil or electric furnace that consumes a raw fuel and makes heat, a heat pump is gathering heat from the outside and moving the heat into your home. In the summer, a heat pump reverses the heat moving process and moves unwanted heat from the inside of your home and disperses it outside. Back to winter heating, moving heat takes much less energy than making heat. How much less?
The efficiency of a heat pump is easiest to understand when it is compared to simple electric furnace. Most electric heaters such as your hair dryer, electric stove/oven or portable heater, are similar to what you see in an old toaster; bright red coils. Since electric heat has no combustion exhaust, we gain any heat made by the electric coils so the efficiency is 100%. But straight electric heat is not the most efficient. That is why the electric heat pump is more commonly used when heating homes. The outside portion of your heat pump does not have any electric coils. Instead, it has a compressor motor that captures the heat from the outdoor air. This heat is actually free, but we do pay a bit to move it. For each dollar that you would spend in an electric furnace to get one unit of heat, a heat pump will use the same dollar of electricity and provide up to 3.5 units of heat. As the temperature outside gets colder this efficiency decreases, but it is still a very efficient 2.5 times better than straight electric coils.
So why does my heat pump run non-stop, 24/7?
Your heat pump is sized for your air conditioning needs and in Central Indiana, this means it will not meet all your heating needs. So here is what happens. In outdoor temperatures above 30 degrees, the heat pump should cycle off and on as a normal furnace. Somewhere between 20 and 30 degrees outdoor temperature, the heat pump for your home will reach a “balance point” where the heat needed by the home is equal to the heat moved by the heat pump. So now it will run all the time. As it gets colder than the balance point temperature, the heat pump will continue to run non-stop, and occasionally backup electric coils will supplement the heat pump. But do not be alarmed by this. The heat pump is designed to run continuously to give you as much of the cheap heat as you can possibly get from the unit, in order to minimize the heat made from the backup coils. As long as the heat pump is allowed to run as it is designed, the backup heat will only account for 10% to 15% of the entire Indiana winter heating needs.
Do not turn off your heat pump!
Some nasty advice is given, even among heating contractors who do not know any better, that you can use the emergency heat setting on your thermostat and “give the heat pump a break when the weather gets cold”. Well take it from me. This switch named “em. ht.” is misnamed. It has nothing to do with getting extra heating capacity or being a cold day setting. It should be named, “DOUBLE OR TRIPLE MY BILLS!” When you switch to “em. ht.”, you turn off your heat pump and now the more expensive backup furnace (toaster coils) are heating your home at two to three times the cost. Don’t do this! Allow the heat pump to run and love it. New heat pumps are very efficient and they are designed to run non stop when you need it most so your heating bill is normal. Even older heat pumps are much better than the electric furnace.
If your heat pump is too old, then its ability to move heat may be less than what it should be. Call Precision Comfort Systems, your Central Indiana heat pump specialists, to evaluate your current heat pump. We can tune it up or eventually replace it so you are getting the most from the current heat pump technology.