When cold weather arrives, your heat pump works harder than normal to keep you and your home comfortable. This is because there’s a larger gap between inside and outside temperatures.
Your heat pump, overall, is relatively efficient. It works by pulling heat from outdoor air and moving it inside. When temperatures are extremely low — or when your system is asked to heat your home quickly — your heat pump may automatically turn on its backup system: electric heat strips.
How Heat Strips Work
Heat strips, also referred to as auxiliary or emergency heat, are electric heating elements built into many heat pump systems. They work much like a large space heater inside your HVAC unit.
When your heat pump can’t keep up on its own, the heat strips automatically switch on to provide extra warmth. This often happens during very cold weather or when you raise your thermostat several degrees at once.
In South Carolina, it’s common for heat strips to activate when temperatures are anywhere from 32°F to 40°F, depending on your thermostat temperature settings and heat pump. While heat strips help keep your home warm, they’re far less efficient and use more electricity to produce heat.
Why Heat Strips Can Increase Demand and Electric Bills
Heat strips draw a large amount of power from the moment they turn on, which means they can have an immediate impact on your energy costs – especially during Peak Hours.
First, they increase your electric usage by consuming more electricity than your heat pump normally would. If heat strips run frequently or for long periods, that extra usage can add up quickly on your bill.
Second, heat strips can raise your electric demand, which is the highest amount of power your home uses at one time. If heat strips activate during Peak Hours, they create a sudden spike in power use, which increases your demand. (The concept of demand can be tricky. You can learn more about demand in this video and learn how you can check your demand in MEL in this video .)
If you’re a customer on the time-of-use rate, using them during Peak Hours, when electricity costs the most, can increase your bills.
In short, heat strips are helpful when needed, but frequent or extended use can lead to higher bills.
How You Can Help Manage Heat Strip Use
The good news is you have control. A few simple habits can help reduce how often heat strips turn on — without sacrificing your comfort.
One of the most effective, no-cost steps you can take is to adjust your thermostat gradually. Increase the temperature by no more than one or two degrees at a time. Large temperature jumps can signal your system to activate heat strips unnecessarily.
Regular maintenance also makes a difference. Change air filters regularly and keep your heat pump properly serviced so it can operate as efficiently as possible.
You can also seal air leaks and improve insulation to help your home hold heat longer. And consider using a smart thermostat to help manage temperature changes and schedules.
Space Heaters and Safety
You may want to consider using a space heater to boost the temperature in one room while it’s occupied, but space heaters are not very efficient at heating your whole home.
While space heaters offer a helpful source of extra warmth, always follow the manufacturer’s safety regulations and these safety tips:
Check the cord to make sure it’s not frayed. Do this before you plug it in to avoid touching a damaged cord that’s connected to an electric source.
Keep an appropriate amount of distance away from other objects. A good rule of thumb is to keep objects at least 3 feet away from a space heater.
Do not drape clothing, slippers, blankets, towels, etc., over the heater to warm them up. That includes keeping your hands and feet at a safe distance.
Turn off the heater when you leave the room or plan to sleep.
Stay Warm, Stay in Control
Heat strips are an important backup on extremely cold days and understanding how they work can help you avoid unwanted surprises on your electric bill. Small adjustments and smart habits can help keep you warm while also helping you manage demand and energy costs all winter long — without giving up comfort.