Heating and cooling costs equal approximately half of your home’s energy budget.A heat pump can be used year-round, warming your home in the winter and cooling it in the summer. It also offers cost-savings, choice and comfort. Since a heat pump can both heat and cool a house, wouldn't you always rather buy a heat pump than a central air conditioner? And wouldn't you rather have a single piece of equipment to purchase, install, and maintain than both a central air conditioner and a furnace? In some cases the answer may be this simple, but there are several factors to first consider that may affect your choice.
Depending on your climate, a heat pump can be a wise energy investment that can result in significant savings on your monthly utility bills. The seasonal weather in our region is probably the most important factor in this decision. If the temperature hasn't dipped below 40 degrees Fahrenheit, you could probably heat your home more affordably with a heat pump than a furnace. However, when the temperature is colder, you should consider having a supplemental heat source such as a furnace. A furnace can more easily maintain warm temperatures when the difference between the temperature outside and inside increases. Second, heat pumps are generally more expensive than a central air conditioner of the same efficiency and capacity. For example, a 1.5 ton, 13 SEER heat pump retails for about $100 more than the equivalent 1.5 ton, 13 SEER central air conditioner. It may also cost more to install a heat pump than a central air conditioner. A third criteria to consider is longevity. Since a central air conditioner is typically only used during the summer months, while a heat pump is used during both summer and winter, the lifespan of a heat pump is typically shorter than that of a central air conditioner. Maintenance costs are typically higher as well, since the heat pump's compressor, controls, and other components will run more months out of the year.
Finally, natural gas and oil have historically been more affordable than electricity. However, as petroleum costs have gone up, this may no longer be true. Since heat pumps almost often run on electricity, you'll want to consider whether a gas furnace would be cheaper. It's important to research your costs in making this decision. Heat pumps today aren't the same as the early models from the 1970s and '80s. They're more efficient. They've got the supplemental heat thing figured out. And they come in a wide variety of efficiency, capacity, and technology, from the standard models to mini-splits to ground-source heat pumps. Of course, furnaces (and boilers) have come along, too. We now have high-efficiency, sealed combustion furnaces that can distribute the heat through either forced air or hydronics. You can get a modulating condensing (mod-con) furnace that can adjust the capacity closer to the needs of the house. Overall, it's easier and less expensive to get a heat pump small enough to match the loads of a high performance home than it is to get an appropriately sized furnace. Mini-splits are great for this and allow for better zoning, too.
A heat pump that is too large for your house cycles on and off too often, which increases the wear on the equipment and decreases its efficiency. Too small, and the unit may not be able to keep you comfortable during both summer and winter.
Unfortunately, there is no shortcut to an accurate measurement: you need to get an HVAC contractor to calculate your house's heating load. The standard measure of a heating load is a Manual J calculation, and it takes into account your house's insulation, size, amount of shade, and many other factors. So, what is a heat pump?