Sizing Your Heat Pump for Optimal Efficiency and Comfort 


“It’s so hot I can’t sleep!” “It’s freezing in here!” “I’ve got a chill!” These are the types of phrases that we try to avoid by installing efficient heating and cooling equipment in our homes. Iyou’re currently relying on old, inefficient, or ineffective equipment and are looking to update your HVAC system, installing a heat pump may be the way to go. However, to ensure the greatest efficiency, reliability, and comfort, there are many factors to considerCheck out the five steps below to guide you through the decision-making process 

Step 1: Understand whether a heat pump is appropriate for your home.    

Even in cold climates, air-source heat pumps can both warm and cool your home by extracting and transferring heat in the air. When it’s warm outside, the heat pump removes heat from the indoor air and transfers it outside, and, when the weather is cooler, the heat pump removes heat from the outdoor air and transfers it inside.  

If you’re currently using oil or propane to heat your home, making the switch to an electric heat pump can be a great way to lessen your environmental footprint and save on heating costs; plus, the heat pump has the added benefit of also providing cooling during the warmer months. To add on one more benefit, Cape Light Compact offers rebates on heat pumps to residential electric customers.   

However, if you are satisfied with your existing heating system and aren’t interested in installing a heat pumpyou may want to still explore energy-efficient cooling options. For instance, you may consider installing a central air conditioning or a window unit to complement your existing heating equipment, both of which the Compact also offers rebates for. If you’re not sure which option may be right for you, the Compact can help by starting you off with a free home energy assessment 

Step 2: Find a qualifying HVAC contractor.  

If you determine a heat pump is for you, you will want to find a Massachusetts-licensed HVAC contractor to install the system. The Sponsors of Mass Save®, including the Compact, offer additional training for these contractors to ensure they install the best equipment for your home. You can find a licensed contractor through this convenient contractor search tool 

Step 3: Calculate heating and cooling loads.  

If you select a heat pump that is too small or too large for your home, it will not only fail to create a comfortable living space, but it will also use excess energy. Units that are too small will run continually as they attempt to meet the desired room temperature, whereas units that are too large will cycle on and off frequently as they quickly reach the desired temperature, shut off, and then cycle back on to re-attain that temperature. Both scenarios will age the unit, waste energy, and add to energy costs.  

How do you go about making sure to select a correctly-sized unitA certified contractor can guide you through this process, which begins by determining the heating and cooling load of your home. The heating load is the amount of heat that needs to be added to your home to maintain a desired temperature, whereas the cooling load is the amount of heat that needs to be removed to maintain a desired temperature. Both the heating and cooling loads are typically measured in either Btu/hr or in tons, with one ton equal to 12,000 Btu/hr.  

The Air Conditioning Contractor’s Association of America (ACAA)’s Manual J and S provide guidance on completing these load calculations, which take into consideration factors such as square footage, climate, insulation, air tightness and leakages, and solar gains.   

Step 4: Find an efficient unit.  

Once a contractor helps identify an appropriate unit for your home, it’s important to opt for an energy-efficient model that is also specifically designed for cold climatesContractors can guide you toward efficient models, as indicated by key ratios, such as SEER (seasonal energy efficiency ratio), energy efficiency ratio (EER), and heating seasonal performance factor (HSPF). EPA’s ENERGY STAR® program explains the meaning of each of these ratios here 

Step 5: Install and maintain the unit.  

While a contractor will handle installation of a heat pump, there are several tips for maintaining your unit for optimal and efficient operation. Ensuring appropriate thermostat settings, regularly cleaning and replacing air filters, and scheduling periodic servicing of your unit based on manufacturer recommendations are just some of the steps you can take to ensure your heat pump operates correctly.  


Making updates to your HVAC system can be overwhelming, but the Compact and certified contractors across the Cape and Vineyard are here to help make the process smooth and convenientIf and when you decide a heat pump is for you, we’re ready to help: you can get started by exploring these FAQsfinding relevant rebates, or chatting with one of the Compact’s representatives at 1-800-797-6699