High-efficiency heat pumps not only cool and heat, but also purify indoor air and improve the comfort of your home. There are many reasons why an air source heat pump could be a good fit for your home and needs:

• High-efficiency heating and cooling. Heat pumps provide both your heating and cooling capabilities in one unit. Modern high-efficiency heat pumps are as efficient as top-tier central air conditioners and are 2-4 times more efficient than traditional electric heat.
• Enhanced home comfort. Heat pumps give you more control over the comfort levels in your home. Ductless heat pumps can be installed in individual rooms or zones of your home so you can adjust the temperature throughout your home based on your personal needs.
• Health. Burning natural gas (methane) inside our homes can create indoor air pollution. High-efficiency electric heat pumps not only eliminate the risks of these pollutants but also provide air filtration and humidity control to purify the air in your home.
• Flexibility. Heat pumps are a flexible technology that can provide heating and cooling to buildings of all shapes and sizes—regardless of whether you have ductwork or not. Heat pumps are a great option whether you want to replace your entire existing system or just want to add heating or cooling to a one or more room(s).
• Lower your carbon footprint. Heat pumps can be powered by renewable electricity like wind or solar. Even with the current mix of coal, gas, and renewable energy powering our electricity grid, heat pumps are a more environmentally-friendly way to cool and heat your home or water. Pair your heat pump with solar and go entirely green!
• Smart. Room-based units can sense and respond to cold or hot spots. Many are also controllable from your phone—in the house or remotely. Warm or cool your house before you even get home!
• Quiet. Are you tired of loud air conditioners or noisy furnace blowers? Heat pumps are often much quieter than traditional heating and cooling systems. Many high-efficiency models will run continuously rather than blasting on and off, reducing disruption to your home.
• Increased resiliency. Efficiently cooling even one room in a home may be a lifesaver for people vulnerable to excessively high temperatures during heat waves due to a warming climate.

Air source heat pumps are considered to be “renewable” heating and cooling systems because they do not create heat, but rather they move heat existing in the ambient air into your home. This process is powered by electricity, which can also be generated by sourced from renewable sources like solar, wind, or hydro.

Even though Boulder’s energy grid is only about 30% renewable today (and getting greener every year!), a heat pump system powered by grid electricity will still reduce your greenhouse gas emissions from heating by 20-60%! These emissions will continue to decrease from year to year as the utility’s grid becomes greener, whereas the emissions from fossil fuels will always stay the same.

• Performance in extreme cold. Since air source heat pumps rely on extracting heat from outdoor air, the heating output and efficiency of a heat pump decline as outdoor air temperature decline. While high-efficiency heat pumps produce heat down to -13F, you may consider keeping a backup heating system for the coldest days of the year. This could include keeping your existing system in place or adding a supplementary system like portable heaters or electric baseboards. Some centrally ducted heat pumps also have electric resistance backups built into the unit. It is worth noting that it is unlikely your heat pump will stop providing heat entirely: in the last 20 years, Boulder has only had 9 days where the temperature dipped below -10F and only for a few hours at a time.
• Aesthetic considerations. Heat pumps require outdoor (e.g. condenser and piping) equipment similar to a central air conditioner. Ductless heat pumps can also require additional indoor equipment typically mounted high on the wall. EnergySmart contractors and advisors can discuss a variety of options available to you to minimize aesthetic impacts from a heat pump installation.
• Higher installed costs. Heat pumps can cost more upfront than individual fossil fuel or central AC systems, but if your systems are nearing the end of life, “early retirement” and switching to a heat pump could save you more in the long run.

There are few homes where some heat pump solutions might not work. However, if you answer “Yes” to any of the questions below, a heat pump system could be a particularly good fit for you:

• Do you want to reduce your carbon footprint?
• Do you want central air conditioning but don’t have (or don’t want to) install ductwork?
• Do you have persistent hot or cold spots in your home?
• Do you want more control over the temperature in individual rooms in your home?
• Are you sensitive to air pollutants and allergens?
• Do you heat with electric resistance heating and want to reduce your energy bills?

Heat pumps are typically rated for heating efficiency based on their Heating Seasonal Performance Factor (HSPF) or seasonal Coefficient of Performance (COP), both of which describe the system’s efficiency over the course of the heating season. The seasonal efficiency of heat pumps can range from 220% to 300%+ (i.e. COP of 2.2 to 3.0) depending on the system type and application. That means that for every one unit of electricity used, 2.2 to 3 units of heat are transferred into the home.

By comparison, electric resistance heating has a COP of 1. Heat pumps are even more efficient when used in the shoulder season: if you only use your heat pump when the temperature is above freezing (using your existing furnace for backup for colder days), your system may be 300-400+% efficient!

Heat pumps also provide efficient cooling, comparable to the highest-efficiency air conditioners. Ductless heat pumps can give you the opportunity to get AC throughout your home without using loud window units or installing or /expanding your ductwork!

Annual system maintenance, which consists of cleaning air filters and an annual maintenance checkup for the outside unit, costs about the same as annual servicing charges for a central air conditioner or furnace.

Heat pumps have an expected lifetime of about 15 years—similar to the average furnace or central AC system.

A ductless indoor unit is quieter than a refrigerator and much quieter than a typical window AC unit. Ducted heat pumps are no louder than a typical furnace or central air conditioner—and variable-speed systems will switch on and off less frequently, resulting in fewer of the loud, disruptive blasts of air typical of furnaces!

There are water heaters that use heat pump technology (heat pump water heaters or HPWHs), though they are considered different technologies than ASHPs. Other models (e.g. “air-to-water” heat pumps) can provide hot water and heating (through radiant floor or hydronic baseboard heating), but these models are less commonly available in the U.S.

A heat pump installation is typically a straightforward process with minimal disruption to your home. A simple, single-zone ductless ASHP system can be completed in less than a day and only requires a single 2-3 inch hole to be cut (and later, sealed) in your wall.

If you are installing a “multi-zone” ductless system or a ducted system that requires modifications to your ductwork, your installation may take a few days or more to complete.

While intuitively you might assume that you should install a ducted ASHP if you already have ductwork, there may be plenty of cases in which a ductless ASHP might actually be a better option for your needs. Some examples include:

• Do you have poorly sized ducts or inadequate heating/cooling to particular areas of your home? Ductless systems could help you address those hot and cold spots in a less invasive/costly manner than making significant ductwork modifications.
• Do you have a new addition on your home, or are you planning one soon? A ductless system could be a cheaper solution than extending ductwork to the addition.
• Do you want to add zoning for heating and cooling in your home? An EnergySmart contractor can install ductless units and/or modify your ductwork to give you more control over zoning in your home.
• Is modifying ductwork in your home very difficult (or are you concerned about the invasiveness of ductwork modification) Ductless systems could offer you the benefits of switching to a heat pump without necessitating an extensive ductwork retrofit.

Every home (and every homeowner) is different. EnergySmart contractors can help make a recommendation that best suits your specific needs.

Energy savings. If you use an electric resistance tank to heat your water, a heat pump water heater will cut your water heating bill in half or more (and reduce your carbon footprint too!). Depending on your hot water usage, this could amount to $200 in electricity bill savings a year or more!

Dehumidification. While Boulder can be pretty dry, humidity can still be a problem in some basements. A heat pump water heater will greatly reduce (or eliminate) the need to run a dehumidifier in your basement.

Noise. Since the heat pump compressor is located inside your home instead of outdoors, a heat pump water heater will be noisier than a typical water heater—more similar to a window air conditioning unit. Speak with your EnergySmart advisor or contractor if you are sensitive to noise and vibration to learn more about your options.

Cooling effect. Most heat pump water heaters extract heat from indoor air. If placed within a finished space, the heat pump water heater will cool off the room it’s in. While installing a heat pump water heater will typically still offer net energy savings, it will increase your space heating bill a bit to compensate—though on the flip side, it will reduce your need for air conditioning in the summer!

Higher upfront cost. Heat pump water heaters are more efficient than traditional water heaters but will cost more upfront than a typical electric water heater. However, their energy savings will pay for the difference in cost–and rebates from EnergySmart will help to offset the added cost as well.