Heat Pump Vs Electric Furnace - Richard, Thank you for such a great site! We have learned a lot from reading your site and recommend it to all our friends. We have to replace our air conditioner that has an electric furnace for heat. We got several quotes from three different contractors and two of the contractors are recommending replacing the electric furnace with a heat pump system that has electric heat back up. We live in North Carolina and the winters here are relatively mild compared to the Northern states but we are unsure about the heat pump system. Please give us some advice about buying a heat pump over an electric furnace and new air conditioner. Thanks and we look forward to your answer. Robert and Vicky
Heat Pump Vs Electric Furnace with Air Conditioner: Efficiency Factors
Heat Pumps are Common in the South and Provide heat and air conditioning
Thanks for your compliments about the site! I think you would save some money with the heat pump as both the electric furnace and the heat pump use all electric to produce heat but they do it in different ways and the heat pump, if properly installed is far more efficient than when operating in the heat pump mode than the electric furnace. That being said it may sound contradictory I tell you that electric heat for the electric furnace is 100% efficient as all of the heat the electric furnace produces is used to heat your home. Compare that to other forms of heating systems such as a gas furnace where some of the heat produced by the furnace goes up the flue whereas with the electric furnace all the heat produced is used to heat the home through the duct work less and duct losses or jacket losses around the furnace cabinet and duct work. The heat pump is nearly the same as it also consumes electricity to produce heat through the process of refrigeration however the provided the heat pump is similarly sized to the electric furnace in BTU size the heat pump will use less electricity than the electric furnace. Depending on the size of the system and taking an educated guess using experience a heat pump will draw 15 to 20 while the electric furnace is drawing over 30 amps.
Since you are replacing the air conditioner and the electric furnace then installing a heat pump then installing the heat pump will take about the same amount work and installation time to install the heat pump as the air conditioner with electric furnace. The air handler and the condenser will be replaced with a an air handler that is similar to the air handler you have now except there will be some heat pump controls versus the electric heat controls that are used to control the electric furnace now. The evaporator coil for the air conditioner will be replaced with a special evaporator coil that is used with a heat pump as a heat pump coil is different than a coil used for an air conditioner. The new system whether you choose an air conditioner with an electric furnace or a heat pump system will probably need a new line set installed. The line set is the copper pipe that connects the evaporator coil inside the air handler or duct work (for a cased coil) and condenser outside. Both the air conditioner with the electric furnace and the heat pump systems needs this piping and usually I recommend this line set pipe be replaced but there are rare circumstances where the line set will not be replaced. I would recommend to you that you insist the line set be replaced even though it will add over $500.00 to the installation cost (depending on the length of the run) but you will have a virgin refrigeration system and that will eliminate any possible problems for you in the future. Believe me it is worth the cost and will save you in the future. The air conditioner condenser and the heat pump condenser installation will be the same aside from some additional control wires for the heat pump and maybe an additional control for the heat pump system (outdoor thermostat) . The additional control wiring for the heat pump can be run at the same time they run the new line set. One of the last things to mention that will be different from the air conditioner with an electric furnace over a heat pump will be a heat pump thermostat so the old thermostat you have will need to be replaced with a new heat pump thermostat.
Backup Heat Use
Most heat pumps have electric heat back-up but this only comes on when the heat pumps goes into the defrost cycle or when the temperature gets really cold outside and the heat pump can’t keep up with the load with the load being the heat loss from your home. In North Carolina you should use the back-up electric heat less often than if you lived in the North. Another option for you if you have natural gas available will be to have a dual fuel heat pump installed where the back up heat is a gas furnace rather than the electric furnace or electric heat strips inside the air handler for the heat pump. This more expensive than having electric heat strip for back-up heat and depending on the efficiency level of the gas furnace compared to the electric heat strips will depend on how much you would save over the electric heat back up versus the gas back up heat. If you install a dual fuel heat pump it requires a lot more work as the flue must be installed and a gas line needs to be ran to the new gas furnace.
If it was my house and I had to decide between an electric furnace with an air conditioner Vs a heat pump I would definitely choose the heat pump as I know I would save money on my electric bill. The final deciding factor for you if you follow my advice will be deciding the efficiency rating for the heat pump. Heat Pumps are rated by HSPF (Heating Seasonal Performance Factor) where the minimum HSPF rating for heat pumps being sold is 7.7. The HSPF is a calculation done to determine the efficiency of the heat pump and the higher the number the more efficient. It is a basic formula the takes the amount of energy used to produce the amount of heat it delivers. Compare prices from the lowest efficient to the highest efficient and make a decision based on the cost of the installation with your budget for the new system.
Heat Pump Vs Electric Furnace - Additional Considerations
Another consideration is where you live and the average temperature in the winter time. The average conventional heat pump does not do well in the Northern states but there is a manufacturer that makes a heat pump designed for those Northern states where the temperature outside in the winter time goes to the extreme. The manufacturer is called Acadia heat pump and the produce these heat pumps that work well in the Northern states even when the temperature outside is very cold. So no matter where you live (unless you live at the North pole) then you can have a heat pump. If the HVAC contractors are recommending a heat pump to you then most likely heat pumps are prevalent in your area so this should not be a worry to you. In the heat pump Vs the electric furnace the heat pump should still be ideal for you.
One last consideration with a heat pump Vs an electric furnace is that you can also choose a geothermal heat pump and save a lot of money on your power bills as geothermal systems are very efficient. However the costs are very high considered to the conventional heat pump system and there are limitations for a well system or a trench system.
Good luck to you Robert and Vicky and I hope I have enlightened you with the Heat Pump Vs the Electric Furnace.
Heat Pump Vs Electric Furnace