Disadvantages of air source heat pumps
Air source heat pumps do have some disadvantages to them. They're more expensive than gas boilers for one, both in terms of set up costs and running costs, and even though they're low-carbon, they don't run on 100% green electricity.
Heat pumps depend on fans to blow the cool air into your home. A common problem with heat pumps includes malfunctioning fan motors. If the motor is not working, the air flow will drop to nothing, which is just as problematic as an inability to generate cool air in the first place.
Difficult to install
Before installation research must be undertaken to understand the movement of heat, local geology, and the heating and cooling requirements for the property. Thus, compared to traditional boiler replacements, heat pump installation requires significantly more planning and preparation.
Heat pumps loose their effectiveness (not to be confused with their efficiency) the colder it gets outside forcing you to either use the electric heat or stay cold. Systems that are designed poorly so the ductwork is too small resulting in a lot of air noise and drafts that is not as warm.
In colder climates, 95% efficient gas furnaces fare better than ENERGY STAR® heat pumps. And, due to the relatively lower cost of natural gas versus electricity, lifetime operating costs should be considered as well.
Contractors avoid deploying more heat pumps because of money. I'm told they are too expensive to sell, when a furnace is another, cheaper solution. Additionally, the incentives are diverse in their scope and in some cases daunting to navigate for both contractors and customers.
A heat pump is an electrical appliance, so running one will add to your electrical use. In many cases, however, that additional electrical use is offset by savings elsewhere. You may also decide that the increased comfort is worth the additional energy costs.
But heat pumps work to cool homes, too, and are capable of working in hot weather, just like an air conditioner. According to the Department of Energy, heat pumps work as well at conditioning an equivalent-sized space as an air conditioner but they dehumidify better and work more efficiently.
A heat pump works best when the temperature is above 40. Once outdoor temperatures drop to 40 degrees, heat pumps start losing efficiency, and they consume more energy to do their jobs. When temperatures fall to 25 to 30 degrees, a heat pump loses its spot as the most efficient heating option for an Atlanta home.
A water tank is not typically required with an air source heat pump when used for heating or cooling. However, a water tank will be needed when an air to water heat pump is also being used to provide domestic hot water, as a heat pump can't provide sufficiently hot water on demand.
An alternative to a heat pump – electric heating
These can store heat when, for example, electricity is cheapest and use it at a later time. This reduces the costs associated with electricity consumption somewhat. Another solution is electric underfloor heating in the form of cables, mats, or special foils.
Once you understand how a heat pump operates, we can explore some possible reasons why a heat pump might blow cold air, such as incorrect thermostat settings, clogged air filters, a dirty outdoor unit, or issues with the reversing valve.
For this reason, heat pumps start to lose efficiency at around 40 degrees F and become less efficient than furnaces at around 25 degrees F. Heat pumps continue to be effective at cooling the indoors, even at high temperatures. In the South, it rarely gets below 25 degrees.
Low maintenance: Once installed, ASHPs only require occasional checks to ensure that they are still operating properly. Usually, this can be done once every 2–3 years. Long lifespan: ASHPs have a lifespan of about 10–15 years.
While in heating mode, a heat pump can consume between 0.86-9.00 kWh per hour, 6.86-72 kWh per day, and 205.71-2160 kWh per month. The cost of operation at $0.15/kWh is $30.86-$324 per month. One way to offset the costs of heat pump electricity usage is by installing solar panels.
Compressors are one of the most expensive parts to repair or replace, with average costs ranging from $1,000 to $2,500 for replacement. However, these heat pump repair costs can vary widely based on the heat pump model, size, and refrigerant type.
Very Cold or Hot Weather. In more extreme temperatures, air source heat pumps require more electricity to warm or cool the air in your home. Increased electricity usage reduces the heat pump's efficiency and drives up the costs of running it. Air source heat pumps transfer rather than generate heat.
Cold-Weather Limitations
This decline in efficiency can lead to higher energy costs, prompting the need for a backup electric heating element or a gas furnace (dual fuel system), especially in colder climates in the Midwest and Northeast.
Geothermal heating is one alternative to a heat pump replacement. While it operates similarly to a conventional heat pump, geothermal heating pulls the heat from the earth rather than the surrounding air, and it transfers it through below-ground piping.
Heat pumps also require different maintenance compared to furnaces and air conditioners. It's a simpler system, and twice-yearly maintenance keeps it running smoothly.
No, most houses don't need a furnace with a heat pump. A heat pump can provide all the heating and cooling for your home by itself. (If you live in a very, very cold climate, we might recommend supplementing your heat pump with another form of heating.)
A range of 68-70 is the best setting in winter if you want to save money because your furnace or heat pump doesn't have to work as hard as it does to reach a higher set temperature. The DOE says the smaller the difference is between the indoor and outdoor temperatures, the more you can save.