You may have heard of a heating & cooling technology called a heat pump, but if you’re not an HVAC pro or an energy efficiency specialist, you probably don’t know what they are or how they work. Heat pumps aren’t new, but they have gained favor lately as energy efficiency and emissions reduction become social priorities.
This article is meant to give homeowners all the information they need to know about heat pumps so they can decide if they are the right technology for their home.
Heat pumps aren’t new, but they have gained favor lately as energy efficiency and emissions reduction become social priorities. This article is meant to give homeowners all the information they need to know about heat pumps so they can decide if they are the right technology for their home.
A heat pump is a climate control system that draws heat from an ambient environment and amplifies it through compressed refrigerant. In short, a heat pump pumps heat from one environment into another.
A heat pump can draw heat from the air (air source heat pump), from water (water source heat pump) or from the soil (ground source heat pump).
Air source heat pumps are by far the most common in residential applications and for that reason, this article will focus on this type of heat pump.
How do heat pumps work?
An air source heat pump uses the heat in the surrounding air to add heat to a refrigerant fluid and then compress the refrigerant, which elevates its temperature. The best feature of heat pumps is that they are capable of climate control in all seasons. They can reverse flow of refrigerant meaning the heat pump can heat the indoors or draw heat from the indoor air to lower indoor temps.
Summer
One common misconception about heat pumps is that, since ‘heat’ is in their name, they are a heating system. In reality, heat pumps are much more efficient when used as a cooling system than a heating system. In summer, an air source heat pump passes the indoor air over refrigerant coils to allow the refrigerant fluid to absorb heat from the air.
The refrigerant is compressed and pumped outside where the heated refrigerant diffuses heat into the surrounding air.
Winter
Another misunderstood component of heat pumps is how they can draw heat from outdoor air in winter, when the air outside the home is colder than the air inside. Air may feel cold to our skin, because it is much colder than our internal body temperature, but speaking in terms of thermodynamics, air that feels cold does still hold thermal energy which can be converted to heat.
Refrigerants exposed to outdoor air can still absorb thermal energy. Compressing that refrigerant to a higher pressure can then further increase its temperature without needing to apply additional heat.
When this heated refrigerant is pumped indoors, it is applied to indoor air and the heated air is circulated throughout the home just as it would be with a conventional furnace or boiler system.
There is one caveat when it comes to using heat pumps as an indoor heating system. After outdoor temperatures drop below 40F, it becomes very difficult for refrigerants to absorb enough heat from the air to be able to heat the indoors.
Why are heat pumps a good choice for the environment?
Heat pumps are usually touted for their reduced emissions and improved energy efficiency. Energy efficiency is one of the primary benefits of a heat pump. It achieves this in a few ways.
Heat pumps are 100% electric. By simply using electricity and refrigerants, heat pumps can achieve efficiency between 300-400% meaning 3-4x the energy input into the heat pump in the form of electricity is output in the form of heat. Heat pumps aren’t creating heat, just moving it around. Whereas a furnace or boiler has to use a heating element to create hot air, heat pumps can use ambient heat to heat a home. Burning fossil fuels at the point of use to collect heat is far less efficient than electrical generation at power plants. Refrigerant technology has improved. Traditional refrigerants like Freon are being phased out due to their ozone depleting properties. New refrigerants have even lower boiling points and are able to extract more heat from ambient environments to be amplified and transferred.
By not burning fossil fuels at the point of use, and due to their great efficiency, each heat pump installed can save up to 228 tons of carbon emissions over its service life!
Heat Pump Benefits
Operational Cost Savings
Heat pumps run on electricity and do not need to burn fuel to generate heat. This makes them highly energy efficient. Electricity is much cheaper than natural gas so these combined efficiencies make the operation of a heat pump much less costly than a traditional furnace and air conditioner combination system.
Energy prices vary from region to region but estimated annual savings on utility bills is $557 for the average American household.
Heat pumps can be installed as part of a ductless heating and cooling system. As the name implies, a ductless system operates without the use of a central ventilation system. The heat pump refrigerant lines can be connected to air handling units, aka condensers or “heads”, which heat or cool the air in a particular zone of the house.
This is a great feature for old homes or cabins that never had ducts installed and could be relying on window mounted air conditioners for cooling.
A ductless system can climate control multiple zones of the house separately. They are also easily controlled independently with a remote and do not require a thermostat.
What are the drawbacks of heat pumps?
Heat pumps are an improved technology in almost every regard but there are still drawbacks.
Cold Weather
When the outdoor temperature becomes too far below the indoor temperature, heat pumps struggle to extract enough heat outdoors to maintain a warm indoor climate. Below 40F, heat pump efficiency begins to rapidly decline and below freezing temps, they become all but
ineffective.
What’s the solution?
Homeowners who live in colder climates where temperatures regularly drop below freezing for long stretches normally opt to keep another heating system in the home such as a traditional gas furnace or boiler system. Combining these two systems ensures the home remains comfortable in all seasons and reduces the workload on the heating system, since it only needs to turn on during the coldest parts of the year, not fall and spring when the heat pump can handle the heating duties. This means the homeowner is using the most efficient system at every time of the year and the reduced workload on the heating system will extend its service life, further protecting the homeowner’s investment.
Installation Cost
As with any technological upgrade or retrofit in the home, heat pumps come with a high upfront price tag. Average heat pump installation cost is $10,750 but these prices can vary regionally and by provider.
What’s the solution?
Heat pumps are subject to numerous tax incentives and utility rebates that can help to lower the upfront cost for homeowners.
Under the Energy Efficient Home Improvement Credit included in the 2021 Infrastructure Investment and Jobs Act, homeowners can receive a tax credit amounting to 30% of the total installation cost of a new air or ground source heat pump, up to $1200.
Utility rebates vary greatly from provider to provider but can be in the 4 figure range. It is best to check your utility provider’s website and discuss rebates with your chosen heat pump installation company.
Where to Start
The Department of Energy recommends that homeowners get an energy audit performed on their home and will give a tax credit up to $150 or 30% of the cost to perform one.
An energy efficiency specialist will tell you areas of improvement for your home relating to your weatherization, appliances, lighting, and water usage.
Once your home is weatherized, you should contact a local HVAC company, such as Aquarius Home Services, that can help you assess your home’s heating & cooling requirements and choose the right system for you.
Don’t sit on the sidelines of this amazing technology. Start saving today!