Frequently Asked Questions
Learn everything you need to know about heat pumps, Comfort365, and incentives and options available to you.
- What is an air source heat pump and how does it work?
- What are the benefits of using an air source heat pump?
- Why are air source heat pumps considered "renewable heating and cooling technologies?"
- Are there other drawbacks to air source heat pumps?
- Is an air source heat pump right for me?
- How energy efficient are air source heat pumps?
- How do the annual maintenance costs of an air source heat pump compare to other heating and cooling systems?
- How long do air source heat pumps last?
- How noisy are air source heat pumps when they are running?
- Can air source heat pumps provide hot water?
- How complicated is installing a heat pump and how much time will it take?
- How well do air source heat pumps work in the middle of winter?
- Does it matter whether I have ductwork or not? Is a ducted or ductless air source heat pump solution is right for me?
- What is a heat pump water heater and how does it work?
- What are the benefits of using a heat pump water heater?
- Are there drawbacks to using a heat pump water heater?
- Is a heat pump water heater right for me?
- What rebates and incentives are available to me?
- What financing options are available to me?
- How much can I expect to pay for an air source heat pump or heat pump water heater?
- What is Comfort365 and who is organizing it?
- How does Comfort365 work?
- Why should I participate now?
- Is participation in this program limited to Boulder County residents?
About air source heat pumps
|What is an air source heat pump and how does it work?||
Air source heat pumps (ASHP) are electric appliances that provide heating and cooling by moving heat into a building (for heating) or out of a building (for cooling). Heat pumps do not create heat like electric resistance heating or fossil fuel-fired heating systems; instead, they transfer heat from the one place to another. ASHPs use the outdoor air as a source of heat.
They accomplish this by using a refrigerant that absorbs heat from colder air in order to move that heat into a space with warmer air—much the same way that a refrigerator or air conditioner works except that it can move heat in both directions to provide both heating and cooling.
Since it takes far less energy to move heat than it does to create heat, ASHPs are one of the most efficient home heating systems available.
Ductless air source heat pumps are exactly as they sound: heat pumps that don't require that you have ductwork in your home to provide heating and air conditioning. Each ductless system includes one outdoor condenser unit connected to one (single-zone) or more (multi-zone) indoor wall, floor or ceiling air distribution units. Ductless ASHPs are often referred to as ductless mini-splits.
Ductless air source heat pumps are the most efficient air-source systems and can be installed as a primary source of heating and cooling or installed to supplement existing systems. These supplemental applications could include, for example, installing ductless units in the most frequently used rooms like family rooms or master bedrooms to displace heating or cooling from your existing system or placing ductless units in rooms or new additions that never seem to be warm or cool enough.
These systems often come with remote controls that allow you to use them for heating, cooling, dehumidification or as a ceiling fan. Because each indoor unit can be controlled individually, you can reduce your energy use even more by lowering the temperature in rooms that are not being used.
Ducted air source heat pumps have an outdoor condenser unit that is connected to a building's ductwork, which is used to distribute heating or air conditioning throughout the building. Ducted (also known as central or unitary) ASHPs are not much different from central air conditioners or furnaces, except that they provide both heating and cooling in a single system. Ducted ASHPs can work with your home’s existing ductwork, though some modifications may be necessary to adapt it from being suited for a furnace to being suited for a heat pump.
Regardless of whether a system is ductless or ducted, all ASHPs will have an outdoor condenser unit (pictured below), which will be mounted on a ground platform or on the side or roof of your building (to avoid snow buildup). This outdoor condenser unit will be connected to one or more indoor air distribution units. If you’re installing a ducted ASHP, this will be a central air handler similar to one used by a furnace or central AC system. If you’re installing a ductless ASHP, this will typically be a wall-mounted unit (see below).
Above: A ductless ASHP condenser and indoor unit; Below: A ducted ASHP condenser
For homeowners that might not have suitable wall space or don’t like the aesthetic look of the wall-mounted indoor unit, floor-mounted and ceiling-mounted units are also available, though these units cost more to install. Photo courtesy of E. Armstrong
|What are the benefits of using an air source heat pump?||
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:
|Why are air source heat pumps considered "renewable heating and cooling technologies?||
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.
|Are there other drawbacks to air source heat pumps?||
While heat pumps are a great fit for many Boulder homes, like other heating and cooling systems they have a few drawbacks:
|Is an air source heat pump right for me?||
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:
|How energy efficient are air source heat pumps?||
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!
|How do the annual maintenance costs of an air source heat pump compare to other heating systems?||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.|
|How long do air source heat pumps last?||Heat pumps have an expected lifetime of about 15 years—similar to the average furnace or central AC system.|
|How noisy are air source heat pumps when they are running?||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!|
|Can air source heat pumps provide hot water?||There are water heaters that use heat pump technology (heat pump water heaters or HPWHs), though they are considered different technologies than ASHPs. Learn more about heat pump water heaters below. 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.|
|How complicated is installing a heat pump and how much time will it take?||
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.
|Does it matter whether I have ductwork or not? Is a ducted or ductless air source heat pump solution is right for me?||
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:
Every home (and every homeowner) is different. EnergySmart contractors can help make a recommendation that best suits your specific needs.
|What is a heat pump water heater and how does it work?||
Heat pump water heaters also use heat pump technology to transfer heat from one place to another. Unlike air source heat pumps, which are used to heat and cool the air in your home, heat pump water heaters extract heat from the air and moves it into a tank to heat water. As a result, heat pump water heaters are 2-3 times more efficient than electric resistance water heaters.
As shown in the diagram below, most heat pump water heaters differ from air source heat pumps in that all of the heat pump elements are indoor and combined with the storage tank. Most heat pump water heaters are “hybrid” heat pump water heaters and include electric resistance heating elements to provide backup heating when hot water demand is high.
|What are the benefits of using a heat pump water heater?||
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.
|Are there drawbacks to using a heat pump water heater?||
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.
|Is a heat pump water heater right for me?||
Do you use an electric resistance water heater? A heat pump water heater could be an excellent investment for you if you currently are using an electric resistance water heater. The savings from going from an electric resistance tank to a heat pump water heater and available rebates will offset the added upfront and pay back your investment over the course of several years.
Do you have a partially finished or unfinished basement with enough clearance? Heat pump water heaters are a bit taller than most traditional hot water heaters and need sufficient airflow to operate at highest efficiency. Additionally, they should ideally be placed in an unfinished space to maximize the amount of heat extracted from the ground and not from heat provided by your heating system. If you have enough space next to your furnace, a heat pump water heater will be able to take advantage of the waste heat generated by your furnace.
A free site visit from an EnergySmart contractor can help you figure out whether a heat pump water heater is right for you. Get started today!
|What rebates and incentives are available to me?||
A variety of rebates for air source heat pumps and heat pump water heaters may be available from Boulder County, the City of Boulder (for city residents), and through your utility. As these incentives are all available on a first-come, first-served basis, the best way to find out what incentives are available is to speak with an EnergySmart Advisor.
|What financing options are available to me?||
Elevations Home Energy Loans are available to help with financing ASHP installation and purchasing. EnergySmart and Elevations Credit Union are working together to offer you these loans that can help you attain a more efficient, comfortable, and affordable home.
Interest rates start as low as 2.75%. Loans can be paid in part or in full with zero prepayment penalty. Home Energy Loans can also be combined with rebates to fully fund your home upgrades. This exciting financing is available to residents throughout Boulder County communities for qualified energy efficiency and renewable energy projects in existing buildings.
|How much can I expect to pay for an air source heat pump or heat pump water heater?||
Pricing will vary depending on your home and your needs: the cheapest air source heat pump applications start at around $4,000 before rebates (e.g. a single ductless unit for a large zone in your home). Heat pump water heaters typically start at around $2,500 before rebates.
|What is Comfort365 and who is organizing it?||
Comfort365 is a partnership between the City of Boulder and Boulder County’s EnergySmart Program to provide residents with a cleaner, more efficient, and comfortable option to cool and heat their homes. Using EnergySmart’s established one-on-one advising model, Comfort365 pairs interested residents with their own personal expert advisor for free! Comfort365 helps residents to explore options for heating and cooling with renewable energy in their home, connect with contractors, evaluate bids and get access to any and all rebates available for your exciting project.
EnergySmart is Boulder County's one-stop shop service to help residents make their homes more comfortable, affordable, and environmentally friendly—benefitting both people and the planet! EnergySmart was started in 2011 and has engaged over 17,000 homes in Boulder County, been replicated across the country, stimulated over $31M dollars in local investment, and reduced almost 14,000 metric tons of CO2 annually. EnergySmart is managed by Boulder County Commissioner's Sustainability Office and implemented locally by CLEAResult.
The City of Boulder's Climate + Sustainability Division works to pioneer pathways and foster collaborative actions that achieve sustainable energy and resource use in our organization and community.This work includes reducing the amount of energy we use in Boulder through energy efficiency efforts, and identifying local, renewable sources to improve community resilience and energy sustainability.
|How does Comfort365 work?||
Comfort365 works just like any other program of EnergySmart—just focused on renewable heating and cooling.
|Why should I participate now?||
There are hundreds to thousands of dollars of rebates available through EnergySmart for heat pumps and other home energy improvements. However, these rebates are only available on a first-come, first-served basis. Get started today to make sure you can take advantage of these rebates.
More broadly, electrifying your home is one of the big steps in supporting our community’s shared efforts to reduce our climate and environmental impacts. Boulder is helping to lead efforts to accelerate our transition off all forms of fossil fuels and you can inspire others to take this important step.
|Is participation in this program limited to Boulder County residents?||Yes. The Comfort365 is a partnership between the City of Boulder and Boulder County. Rebates are limited to residents and available on a first-come, first-serve basis while funding lasts.|