Air source heat pumps, sometimes referred to as mini-splits, are an energy-efficient electric heating and cooling system that can be used to heat and cool either part, or all, of your home. See below to learn more about this technology, including how it works, financial incentives available, ways to prepare your home for installation, and more.
Financial Incentives Available:
Heating System Cost Comparison for HG&E Customers
The chart below compares average annual heating costs for various heating system types in HG&E's territory, accounting for HG&E's electric and gas rates.
How Does an Air Source Heat Pump System Work?
Air source heat pumps consist of two main components: an indoor unit and an outdoor unit. Refrigerant cycles between the indoor and outdoor units, carrying heat from one location to another, similar to how a refrigerator operates. In the summer, heat is moved from inside the home to outside, blowing the remaining colder air back into the house. In the winter, they reverse operation, extracting heat from the outdoor air and transferring it into the home. Because refrigerant has a low boiling temperature, heat pumps can continue to provide heating even during cold winter temperatures. If sized correctly, they can even be used as a home's primary, or only, heating system. The Northeast Energy Efficiency Partnership (NEEP) has published a list of verified Cold-Climate heat pump models that are capable of operating down to 5°F outdoor temperature, while maintaining an efficiency of 175% at that temperature.
Heat pumps can either be connected to ductwork, or, they can be installed without the need for ducts. These 'ductless' systems are often referred to as "mini-splits" and often include a wall-mounted indoor unit connected to an outdoor unit.
Weatherizing Your Home Before Installation
Consider preparing your home for the heat pump before it is installed by first air-sealing and insulating to a proper extent. Having a tighter, more insulated home not only reduces annual heating costs, but might also allow you to buy a smaller heat pump system than you would have needed otherwise. HG&E provides free energy audits to customers which determine cost-effective weatherization improvements you can make to reduce your annual heating and cooling costs. You can also take advantage of Holyoke's weatherization rebates which include insulation rebates of 50% of the cost up to $2,000, and air or duct-sealing rebates (50% up to $500).
Understanding Common Heat Pump Ratings
System Size and Output Capacity: The amount of heating and cooling that a heat pump system can provide depends on its size, or "output capacity". Smaller heat pumps can be used to heat individual rooms or spaces. Larger, whole home systems may have multiple indoor units connected to one or more outdoor units. The output capacity of a heat pump system can vary depending on the outdoor temperature. The NEEP Cold-Climate Air Source Heat Pump List provides the output capacity at various outdoor temperatures down to 5 degrees F.
HSPF: This is the average annual heating efficiency of the air source heat pump system. The HSPF indicates how much heat is produced for each watt of electricity that the system consumes. For example, if a heat pump has an HSPF of 10, this means that the system will output an average of 10 BTUs of heat for every watt consumed throughout the heating season. Ensuring the system has a high HSPF will help lower your annual heating bills.
SEER: This is the average annual cooling efficiency of the heat pump. The SEER rating indicates how much cold air is procdued for each watt of electricity that the system consumes. A higher SEER rating will reduce your cooling costs over the cooling season.
How to Shop for a Heat Pump
The Northeast Energy Efficiency Partnership (NEEP) has provided an Air Source Heat Pump Buying Guide to help you choose the right system for your needs. See pages 13 and 14 of the guide for best practices for choosing a heat pump system and questions to ask a contractor to ensure they are experienced with installing this system type.
Northeast Energy Efficiency Partnership’s Air Source Heat Pump Buying Guide and MassCEC’s Heat Pump Guide are great resources to review to learn more about how air source heat pumps work, which design is right for your home, size and ducting options, and more!