Choosing the right in-home heating and cooling system is an important job. You need a product that will condition the living space safely, sufficiently and efficiently. There are a lot of different options out there, all with their own pros and cons. In this blog, we will shed light on the air source heat pump – a system with some unique features that make it stand out next to most of its HVAC competitors. So without further ado, let’s dive in!
What are Air Source Heat Pumps?
An air source heat pump (ASHP) is an energy efficient heating and cooling unit. It works differently from other combustion heating units because, instead of generating heat, it transfers the heat.
These devices generally consist of an outdoor unit and an indoor unit, which are connected by a refrigerant line. The heat pump works much like a refrigerator in reverse.
The outside unit extracts heat from the outside air. Then it pulls the air through a refrigerant coolant, which is then compressed to increase the temperature of the air. The warm air is then propelled into the home using a fan system.
The heat pump can also act as a cooling device. In this situation, the system pulls in warm from the home and sends it to the outside. Refrigerant is then circulated through the indoor unit, absorbing the heat in the air and redistributing cool and newly dehumidified air.
There are several different varieties of air source heat pumps. You can have a single-zone or multi-zone system, which are fairly self explanatory. A single-zone system consists of one outdoor unit and one indoor unit, while a multi-zone will have one outdoor unit and two or more indoor units, installed in different locations within the residence.
ASHPs also can be ductless or ducted. Ductless systems consist of the traditional configuration – an indoor and outdoor unit, connected by a refrigerant line. These are commonly referred to as “mini-split” systems (shown below). These are generally meant to condition smaller spaces or single rooms.
As implied in their name, ducted ASHPs are configured with duct systems. They are set up the same way a normal HVAC duct system would be; and they can condition a whole home with heating and cooling.
ASHPs can also be installed as split or packaged systems. Split systems, which are the most common, involve one indoor unit with coils and one outdoor unit with coils (depicted in the above “Heating Cycle” diagram). In a packaged system, both coils are located in an outside unit.
The Benefits of Air Source Heat Pumps
Here are a few reasons why air sources heat pumps might be a great fit for you.
Energy efficient: ASHPs are much more efficient than traditional heating systems, such as boilers or furnaces. ASHPs deal with heat transfer, as opposed to heat production. As a result, they require less energy to produce the equivalent amount of heat.
Environmentally friendly: ASHPs are electric, non-combustion systems. So they emit much less carbon dioxide than traditional heating systems, making them a more environmentally friendly option.
Cost-effective: In addition to being more energy-efficient, ASHPs are also cost-effective in the long run, as they require less maintenance and have lower operating costs than traditional heating systems. Additionally, these units are usually only slightly more expensive than stand alone AC units. So if you plan to install an AC system anyway, it might be worth considering an ASHP for both cooling and heating.
Versatile: ASHPs can be used for heating, cooling, and hot water production, making them a versatile option for homes.
Solar-Compatible: Being that these units are electrical, they can be powered by solar panels. That way, if you are looking to convert completely to solar, this type of system is the right fit!
While we love to talk about all the ASHP pros, we would be remiss not to mention the cons.
High Up-Front Costs: Although, in the long run, these systems could serve to save you some bucks, they tend to be a bit pricey in their upfront costs, compared to conventional HVAC products.
Higher Electric Bills: This is to be expected, but nonetheless, something to be aware of. If you convert from a gas-fueled system to an all electric heating/cooling system, your electric bills will increase.
Less Efficient at Low Temps: ASHP are unfortunately not very efficient at low temperatures. Joe Ophoff, our Director of Energy Services, states that “the drawback to [ASHP] systems is that you need an emergency backup of some kind. In our [Colorado] climate zone especially, when it’s super cold outside, a heat pump can’t do the job by itself. So a mini split needs an electric baseboard unit to act as the emergency backup. Even ducted ASHP systems need an electric back up built into the air handlers. Basically, an electric furnace should get installed for the times that the heat pump can’t do the job.”
ASHPs and Energy Code
In this day and age, energy code has become such an important part of the building and remodeling process. One of the key steps in reaching energy code compliance is earning a satisfactory HERS rating.
Several different aspects contribute to the home’s overall HERS rating, including heating/cooling systems. If you are going the ASHP route, it will likely help your HERS rating. Due to their high efficiency design, air source heat pump systems generally yield better HERS performances over gas-fired equipment.
Are you working on a new project or addition, and in need of HERS rating services? Well you came to the right place! At Scott Energy Services, we have a team of certified HERS raters, ready to help you with all of your energy code needs.
Chris Kimmel worked as an Associate Home Inspector for two years, handling numerous services including sewer scope inspections, pest inspections, mold air sample testing, radon testing, and water quality testing. Chris now works with Scott Home Inspection as a Content Writing Specialist.