Air Source Heat Pumps

WHAT IS AN AIR-SOURCE HEAT PUMP?

Air-source heat pump (ASHP) systems, also known as air-to-air heat pumps, can both heat and cool your home with the same unit, using refrigeration technology to transfer heat. The refrigeration system consists of a compressor and two coils made of copper tubing.

In the winter, the unit extracts the heat from outside, down to an average of twenty-five degrees Fahrenheit*, and transfers it into your house to keep you warm. In the summer, the process is reversed, and the unit removes heat from your home and releases it outdoors, keeping you cool. For more detailed heat pump information, visit the Department of Energy’s website in the air-source heat pump section.

HOW MUCH DO AIR-SOURCE HEAT PUMPS COST?

Air-source heat pump cost is generally between $3,500 and $5,000 per unit. That being said, there are a few noteworthy contributing factors to the price you’ll pay to install an air-source heat pump in your home. Here are five things that contribute to ASHP costs:

1. Unit size: The size of the room/area you’re looking to heat significantly impacts the cost of ASHPs. To heat a bigger space or multiple rooms, you’ll need an air-source heat pump that produces a higher level of BTUs per unit, which tends to be more expensive. In contrast, you may pay less for a single zone ASHP used to heat a single room or space.

2. Equipment: As you would expect, different types of ASHPs from different brands will cost you more or less, depending on which one you choose. Depending on the brand's reputation and the kind of equipment you're purchasing, some units may be more expensive than others.

3. Installation costs: Installation is another large contributor to the overall price you’ll pay for an air-source heat pump. Depending on the installation's complexity and the size of the equipment you purchase, you can expect to pay between $60 - $150 per hour to a local installer.

4. Type of equipment: Air-source heat pump cost can vary depending on whether you’re installing a ducted or ductless system. If your home already has a duct system installed, the cost is relatively standard. If your local installer needs to install a complete duct system in your home, the price will substantially increase ($15,000 to $30,000). However, you could install a ductless heat pump system to avoid the added cost of installing ductwork in your home. 

5. Extras and upgrades: Air-source heat pump systems can come with many extras. This could include air filtering systems and humidifiers that can add to the total cost you pay for a system.

WHAT SIZE AIR-SOURCE HEAT PUMP DO I NEED?

Your new heat pump should be properly sized to fit your home. Oversized equipment can cause reduced comfort and excessive noise and will shorten the life of the equipment by causing it to cycle on and off more frequently than a properly sized unit. Undersized equipment with airflow that is too low can reduce the efficiency of the air distribution and accelerate wear on system components, leading to early failure. Equipment should be sized by a heating and cooling professional. See more about sizing below.

AIR-SOURCE HEAT PUMP SIZING CALCULATOR

Sizing can be calculated by a heating and cooling contractor, who will complete a load calculation by taking measurements of your home and asking you some questions. The calculation is usually done using software and should be based on professional guidelines.

A good contractor will not size your equipment solely on the square footage of your house or assume that your existing equipment was sized properly in the first place. Proper equipment sizing is based on your home’s heat loss during cold weather and heat gains during warm weather.

Your contractor will specify the recommended system capacity in either Btu/h (British thermal units of heat removed per hour) or refrigeration tons (one ton being equal to 12,000 Btu/h). As a general rule, for every 500 to 600 square feet of space, you should have 12,000 Btu/h in heating and air conditioning capacity.

Listed below are six questions you should consider when determining what size air source heat pump you should purchase for your home:

1. How well is your house insulated?
2. How well are air leaks sealed?
3. How well are your ducts sealed and insulated?
4. What are the size, type, and number of windows and the direction they face?
5. Is there shade from overhangs and landscaping?
6. What is the size, layout, and orientation of your house?

PROS AND CONS OF AIR-SOURCE HEAT PUMPS

PROS

Air-source heat pumps offer various benefits to those looking to add them to their homes. Below, you can find the most noteworthy advantages air-source heat pumps have when compared to other options.

• Energy-efficient: Delivers 1.5 to 3 times more energy than the electricity it consumes.
• All-year service: Heats your home in the winter and cools your home in the summer.
• Cost-effective: Co-op electricity rates reflect stability, compared to other fuels.
• Environmentally friendly: Heat pumps transfer energy rather than burn fossil fuels.

CONS

Just as there are benefits to installing an air-source heat pump in your home, there are also disadvantages you must consider before installation.

• Cold climate efficiency: Air-source heat pumps can become less efficient when the weather gets colder (Below 32 degrees F) unless you purchase a more expensive cold-climate heat pump model
• Heating time: ASHP’s can take a longer amount of time to heat up
• Noise: They can be noisy when running
• Home insulation: Your home must be well insulated for ASHPs to save you money on energy costs.

TERMINOLOGY EXPLAINED

• Air handler: In a forced-air heating system, the “box” containing the fan that circulates the air.
• Compressor: The central part of a heat pump, the compressor pumps refrigerant to meet the heating or cooling requirements of the system.
• Heating seasonal performance factor (HSPF):  A measure of a heat pump’s energy efficiency over one heating season. A higher HSPF rating equals a more efficient heat pump.
• Seasonal energy efficiency ratio (SEER):  A measure of equipment energy efficiency over the cooling season. A higher SEER rating equals a more efficient heat pump.
• System capacity: A measurement of the total amount of heat or cooling your system can produce in one hour.

CALCULATING THE SIZE OF EQUIPMENT

Sizing can be calculated by a heating and cooling contractor, who will complete a load calculation by taking measurements of your home and asking you some questions. The calculation is usually done using software and should be based on professional guidelines. A good contractor will not size your equipment solely on the square footage of your house or assume that your existing equipment was sized properly in the first place.

Proper equipment sizing is based on your home’s heat loss during cold weather and heat gains during warm weather. Your contractor will specify the recommended system capacity in either Btu/h (British thermal units of heat removed per hour) or refrigeration tons (one ton being equal to 12,000 Btu/h).

*This temperature will vary based on your heat pump model and desired comfort level in your home.