Questions and Answers about the Electric Heat Pump
What is an electric heat pump?
An electric heat pump is a single unit that both heats and cools your home. A heat pump is the most efficient heating and cooling system available today because it generates less than one unit of heat for each unit of energy it consumes.
If it cools and heats, why do they call it a heat pump?
Simple. It pumps heat. In summer, it moves heat from inside your house to the outside. In winter, it moves heat from the air outside to inside your home. This is done using the refrigerant that is pumped by the compressor through the indoor and outdoor coils
There's heat in the outside air in winter?
You bet. Outside air at 0 degrees F. contains 82% of the heat available in the air at 100 degrees F. (get a high school physics teacher to tell you why!). One of the amazing things about the heat pump is that it can extract that heat from the outside air and pump it into your home.
Do you need a supplemental heating system with an electric heat pump?
An electric heat pump operates most efficiently at temperatures above the low 30's. When temperature dip below that, some supplemental heat is required. But don't forget, it's above 32 degrees in our area more than 94% of the time during the heating season. Supplemental heating can be supplied by an electric heater or gas furnace.
Can I save money using a set-back thermostat with a heat pump?
You will save a little more, especially in the summer. The recommended thermostat setting is 78 degrees for cooling and 70 degrees for heating.
I've heard that heat pumps don't keep you as warm as a gas furnace. Is that true?
Some people think that's true, because a heat pump takes a little getting used to. With a heat pump, you don't get those uncomfortable blasts of hot air that you get with a gas furnace. A heat pump keeps the room temperature more constant than a gas furnace, so you're more comfortable all the time. If you're like most people who find that sometimes they're too hot and sometimes they're too cold with a gas furnace, an electric heat pump is probably just right for you.
So a heat pump really does blow cooler air than a gas furnace?
Right. And that's what helps maintain a constant, comfortable temperature in your home that's better tolerated by people, pets, and plants.
Then it must run longer than a gas furnace, right?
Right again. But remember, it produces two to three units of heat for each unit of energy it uses (compared to less than one unit of heat from a gas furnace), so you end up with significant savings at the end of the month.
But if it runs longer and runs during the summer and winter, it will wear out sooner, right?
Wrong. A heat pump is designed to run all year long--like your refrigerator (and when was the last time you had to replace that?) Appliance Magazine says heat pumps have about the same life expectancy as a regular central air conditioner used with a gas furnace. And even the Gas Research Institute admits in a study report that "As the efficiency of heat pumps is increased, their anticipated life increases as well." By contrast, in that same study, the Gas Research Institute suggests that the expected life of gas furnaces will decrease as their efficiency improves.
Do I have to "oversize" my unit with a heat pump or have larger ductwork?
A heat pump uses the same sized ductwork as a typical gas furnace/central air conditioning system. And unlike gas furnaces, which routinely are oversized, you don't need to over-size a heat pump. If you're installing a heat pump in an Energy Action home, you may even need a smaller unit. The reason is because Energy Action homes are built for maximum energy savings.
What about the cooling mode? Are heat pumps less efficient in the cooling mode than typical central air conditioners?
No. Today's heat pumps are generally as efficient as typical central air conditioners.
Source: TU ELECTRIC