How to compare air source heat pump options (2023)

Questions to ask yourself when comparing air source heat pump options

Air to water heat pump systems offer various setup and equipment options. You must answer the following questions before you can make a final decision about your installation, which a qualified HVAC contractor or plumber can assist you with:

• Will you be using air source heat pumps as the sole heating and/or cooling source?
• Do you want a system with or without channels?
• Would you like to heat an entire building or a single room?
• Do you want a split or boxed system?
• For Cold Climates: Will a traditional system suffice for your needs or should you look into a cold climate system?
• For cold climates: Would you like to keep an auxiliary heating option on top of your heat pumps?

Ducted vs. ductless air source heat pump systems

Air source heat pumps can distribute air for heating and cooling throughout a building, either via ducts or via individual wall-mounted units, also known as mini-splits.

Both ducted and ductless air source heat pump systems require an outdoor unit that is located outside of your home. The biggest difference between the two is that a ducted system uses ducts within the walls of your home, while a ductless system does not. In a duct system, the outdoor unit is connected to an indoor unit that moves the warm or cool air through your ducts and around your building. The air exits through the vents that your ducts are connected to. Ductless systems, on the other hand, have individual indoor units placed in a room. Also known as mini-splits and often referred to as 'heads', these units are directly connected to the outdoor unit(s) via refrigerant lines that transfer and push the warm or cool air into the room.

When a ducted air source heat pump might be right for you

You should consider a duct heat pump system if:

• You already have existing ducts in your house that you can use for heat pumps. However, in some cases you may need to make upgrades to your ductwork or electrical system during the installation process to ensure the heat pump distributes air efficiently.
• You value the aesthetics of individual units on the wall, so prefer not to have mini-gaps visible in your living space. (This is becoming less of an issue as heat pump manufacturers continue to develop new low-profile heads.)

When a ductless air source heat pump could be right for you

You may want to consider a channelless mini split if:

• You have no existing channels. A ducted system takes longer to install and costs more than a ductless system. Ductless systems have fewer design requirements and tend to be less expensive than ducted systems.
• You have a smaller living space for heating and cooling.

Short term air source heat pump systems

Another option that's sort of a hybrid between the two is a short-term or mini-duct system. This type of installation involves ductwork, but it only runs through specific parts of the home and not through a central duct system. Then you can install ductless units anywhere in your building where the existing ducts are not used for heating and cooling.

Single zone vs. multi-zone heat pump systems

A single zone air source heat pump system is only intended to heat a small space, typically one room. Single zone systems have an outdoor unit connected to an indoor header to heat or cool the area.

If a one zone system might work for you

Single zone heat pump systems are the right choice when you only want to heat or cool a small area of ​​your home. A common use of a single zone system is to heat or cool a newly constructed addition to your home while the rest of the home is running on central air conditioning. You can install multiple single zone systems, but if you want to heat or cool many rooms with air source heat pumps, it is more efficient to install a multi-zone system.

When a multi-zone system might be right for you

A multi-zone heat pump system can heat and cool multiple areas of a home using multiple heads in different areas, all connected to a single outdoor condenser. By installing a multi-zone system, you can simultaneously heat or cool different "zones" within your property to different temperatures. For example, during the hot summer months, you can set the temperature of the room you spend most of your time in to a lower temperature, while other zones are set to a higher temperature to reduce your overall energy consumption.

Split vs Packed Air Source Heat Pump Systems

Many heat pump systems today are split, meaning they have two coils: one inside and one outside. The coils of an air source heat pump system are the component that actually heats or cools the air. Split systems come in both ducted and ductless systems.

In comparison, in a compact heat pump system, coils and fans are located on the outdoor unit, while heated or cooled air is distributed throughout the house via ducts. Packed systems tend to be less efficient than split systems, but installation is typically less labor intensive (and therefore less expensive) than split systems. Boxed systems also take up less space overall and may be worth considering if you have a home with limited space available.

Conventional vs. heat pump equipment for cold climates

It wasn't too long ago that you might hear someone say that heat pumps can't work efficiently in cold climates. However, in recent years, cold climate air source heat pumps have improved and are designed to be more efficient for heating homes in colder regions such as New England or the Midwest. Cold climate air source heat pumps can be either ducted or ductless, single zone or multi-zone, but to be considered a “cold climate” system they must meet certain efficiency criteria. More efficient air source heat pumps tend to be more expensive upfront.

Comparison of other HVAC systems with air source heat pumps

If your existing heating or cooling system is aging or not working properly, taking a look at air source heat pumps can help you heat and cool your home more efficiently. Here are some ways that heat pumps hold their own against other HVAC options:

Electrical resistance heating (skirting board heating)

Air source heat pumps use electricity more efficiently for heating than baseboard heaters, resulting in an average annual electricity saving of $459 in the Northeast and Mid-Atlantic compared to electric resistance systems. In addition, with individual air source heat pump units in your home, you can set different temperatures in different rooms or zones in your home.

natural gas heating

You can use air source pumps for a quieter, cleaner, and healthier option compared to natural gas. Fewer emissions help you improve air quality, and less noise can increase comfort when heating and cooling your home. Zone temperature control also helps you heat more efficiently and usually saves money too.

Heating oil or propane gas

Some of the biggest savings are possible when comparing air source heat pumps to oil or propane heaters, with homeowners in the Northeast saving an average of $948 annually by replacing an oil system with heat pumps. As compared to natural gas, air source heat pumps are also quieter and ensure lower emissions and better air quality. Convenience is another benefit touted over oil heaters, as you don't have to schedule fuel deliveries or worry about oil price freezes.

air conditioners

When it comes to cooling, air source heat pumps offer many advantages over traditional air conditioning (A/C) systems. Heat pumps cool more efficiently and allow you to cool specific areas in zones, so you don't have to worry about cooling rooms where you don't spend as much time during the day. If you choose a ductless air source heat pump system, the installation is much less intrusive than the extensive ductwork that central air conditioning systems require. Heat pumps are also often more convenient as they dehumidify the air better and more efficiently than air conditioners.

window air conditioners

Because air source heat pumps cool your home more efficiently than window air conditioners, you pay less on your electricity bill every summer. There is also an added convenience factor as you don't have to take out air source heat pumps in the cold months and have to reinstall them every spring or summer. Window air conditioners are also noisier and can contribute to air leaks through the windows you have them installed on.

Evaluation of different air source heat pump technologies

Once you have decided what type of air source heat pump installation you are going to proceed with, you need to choose the equipment you will be using. There are three ratings and certifications to help you make your decision:

• SEER evaluates how efficiently an air source heat pump cools a room.
• HSPF evaluates how efficiently an air source heat pump works in heating mode.
• ENERGY STAR is a government rating given to high-efficiency equipment that meets certain standards.

MAGIC

The Seasonal Energy Efficiency Rating (SEER) evaluates a system's cooling efficiency, making a high SEER rating particularly important in warmer climates. Federal regulations require a minimum of 13 SEER for homes in the Pacific Northwest, Northeast, Midwest, and Mountain states. For households in warmer parts of the country, the SEER requirement will be raised to 14. Generally, the higher the SEER, the more expensive the system, but if you live in a particularly warm climate it may be worth paying for a system that's more efficient for your own comfort.

HSPF

The Heating Seasonal Performance Factor (HSPF) assesses the heating efficiency of a system, making it the equivalent of SEER in cold climates. If your property is in a colder climate, you should look for a system with a higher HSPF. An HSPF rating of 7.7 is required by federal law for all air source heat pumps.

ENERGY STAR-Label

Air source heat pumps with an ENERGY STAR label are certified by the Department of Energy as being above average in efficiency, making them the best choice for saving energy (and therefore saving on your utility bills). ENERGY STAR level air source heat pumps have high SEER and HSPF ratings. To earn an ENERGY STAR label, an air source heat pump must have a SEER greater than 15 and an HSPF greater than 8.2 for single pack systems and 8.5 for split systems.