Winter-Ready Heat Pumps: Unveiling Cold Weather Performance

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By Debarghya Roy

Are you worried that a heat pump won’t work in cold weather? You’re not alone. Many homeowners are concerned about the performance of heat pumps during winter months and whether they can be used as primary heating sources in colder climates.

In this blog post, we’ll look at how heat pumps work in cold weather, the advantages and limitations of using them.

Key Takeaways

  • Modern cold weather air source heat pumps can operate efficiently up to – 15°F.
  • Heat pump performance and energy efficiency in cold climates is affected by outdoor temperature, wind speed, precipitation and humidity levels.
  • Proper installation and maintenance of a heat pump is critical for optimal performance in cold temperatures.
  • Homeowners living in colder regions may need supplemental heating options such as furnaces or boilers to get the most out of their heat pumps during winter months.

What Is a Heat Pump? 

Heat pumps are a type of mechanical system that utilizes energy found in outdoor air to transfer heat from a cool space into a warm space, similar to how a refrigerator or air conditioner operates.

How Does Heat Pumps Work?

Heat pumps use the natural process of evaporating and condensing refrigerant to move thermal energy back and forth between indoor and outdoor locations. 

do heat pumps work in cold weather

This technology helps homeowners capture heat energy from outside, even when temperatures drop below freezing.

Inside the pump, coils extract the ambient heat outside of your home and distribute it inside.

A fan is used through an outdoor unit surrounded by coils; as these absorbed chilled fluids pass through them they become warmer and enter your home’s airspace with comfortable warmth.

How Heat Pumps Work In Cold Weather?

Heat pumps are air-source systems that provide efficient home heating with the help of refrigerant technology. 

Conventional heat pumps use a compressor to draw in outdoor air, which is then exposed to its cooled inside units and heated by vapor compression.

In winter, this process is reversed so that exterior heat can be delivered indoors as warmth for the house.

Heat pump systems contain two sets of coils: indoor and outdoor ones. 

The refrigerant absorbs ambient heat from the outside source and delivers it into your home through a reversing valve located in the split-system unit or packaged system.

As cold weather approaches, many homeowners worry if their system will still run efficiently outside optimal performance conditions (50 degrees Fahrenheit).

Factors Affecting Heat Pump Performance In Cold Weather

include outdoor temperature, wind speed, precipitation and humidity, which all play an important role in heat pump efficiency.

Outdoor Temperature Threshold For Efficiency

Heat pumps utilize a transfer of energy from one area to another in order to provide heating and cooling. 

In moderate weather, they typically operate at up to 400% efficiency.

However, as temperatures drop beyond a certain threshold, their efficiency decreases rapidly. 

Generally speaking, heat pumps start losing some of their efficiency when outdoor temperatures fall beneath 40°F (4.4°C).

While some systems will still operate properly below this point, the general rule of thumb is that heat pump owners should avoid operating them in more extreme cold temperatures unless absolutely necessary or the unit has been specifically designed for colder climates.

In addition to outdoor temperature considerations, various other factors can further impact the performance and energy efficiency of heat pumps in cold weather periods, Such as,

  • Wind speed/directional changes which can increase losses around compact storage tanks reducing water temperature and drastically lengthening electric cycles; 
  • Precipitation levels dampening coils.
  • High humidity creates an environment where latent loads cannot be effectively met.

Plus improper installation/maintenance leading significant loss in capacity making even normal operations impossible for longer durations during extremely cold periods outdoors.

Importance Of Proper Installation And Maintenance

Maintaining proper installation and maintenance of a heat pump is crucial for achieving optimal performance in cold weather. 

Heat pumps need to be properly sized for the space, installed according to the manufacturer’s instructions, and attended to by qualified technicians regularly.

If a heat pump is too small or large, or improperly insulated, it can have poorer efficiency and will struggle with heating during colder temperatures. 

According to National Renewable Energy Lab (NREL), regular checkups conducted by certified service providers are recommended as misaligned parts may nullify an estimated energy savings of up to 20%.

To ensure optimal performance in cold weather climates, homeowners should perform basic maintenance tasks such as,

  • Replacing air filters regularly
  • Keeping indoor coils clean 
  • Clearing snow away from outside units before winter arrives
  • Checking electrical connections
  • Testing thermostat batteries twice yearly etc. 

For safety purposes all installations should be done using UL listed HVAC materials and adhere strictly to local codes or permits that may apply in certain regions.

Solutions For Heat Pump Performance In Cold Weather

To get the most out of a heat pump in cold climates, homeowners may need to invest in supplemental heating options, such as electric resistance heating or fuel-fired systems.

Supplemental Heating Options

Although heat pumps are designed to be efficient in cold climates, there may still come times when supplemental heating solutions become necessary. 

To ensure homeowners receive a consistent and reliable stream of warm air during frigid winter months, many turn to supplemental heating options. 

These can include furnaces, boilers, electric resistance heating (coils or strips), or dual fuel systems that combine a heat pump with the traditional gas furnace.


  • One of the most popular options is a forced-air furnace
  • Forced-air systems utilize heated coils inside an enclosed box connected by ducts that transport warmth throughout the home via blowers. 
  • Heat pumps supplemented by furnaces will cycle on and off as temperatures drop allowing other sources of energy, typically natural gas to take over .


Boilers offer another form of supplementary heating system for homes equipped with hydronic radiators or baseboard units used as radiant source for supplemental heat during colder temperatures outside the range of what heat pump technology can handle.

Choosing The Right Size And Type Of Heat Pump

Selecting the correct size and type of heat pump is essential for optimal performance in cold weather climates

Heat pumps transfer heat from one place to another by using a refrigerant gas, but also require electricity for operation.

It is important to choose the system that best fits the needs of your home and weather conditions. 

When selecting a heat pump, consider factors such as climate, regional temperature extremes during summer and winter months, energy efficiency requirements, budget constraints, and indoor air quality needs.

The size of your home’s heating system will determine its ability to effectively warm or cool the entire space. 

Generally speaking, all systems are sized based on 47-degree ambient temperature ratings which means it takes into account heated air capacity during hot days including outdoor temperatures over 100°F or colder temperatures below 0°F 

It is essential to get the right sizing not too small where it has difficulty heating/cooling nor too large so that you end up paying more upfront than necessary with higher utility bills due to fuel loss from surplus running times.

Proper Installation And Maintenance

In order for a heat pump system to work efficiently in cold weather, it is important that the unit is installed correctly. 

Even if you have purchased an energy-efficient system, improper installation can lead to decreased performance and efficiency – resulting in higher bills for homeowners.

Common mistakes include not properly venting exhaust gasses or leaving gaps between the pipes of an air conditioning condenser unit.

Along with being installed correctly, it’s also essential that your heat pump receives regular maintenance from qualified technicians during both summer and winter months.

Clean air filters are vital during cold weather to maximize heating capacity and improve airflow around the machine as this helps the compressor operate at optimal levels which reduces wear on moving parts.

Advantages Of Heat Pumps In Cold Weather

include increased energy efficiency and cost savings, reduced environmental impact, improved indoor air quality and greater levels of comfort even in colder temperatures.

Increased Energy Efficiency And Cost Savings Of Heat Pumps

Heat pumps are an energy-efficient and cost-effective way to cool and heat homes in both warm and cold climates. 

Unlike traditional furnaces or air conditioners, heat pumps use much less energy to move existing heat from one place to another instead of generating it.

This reduces the amount of electricity needed to maintain comfortable temperatures inside the home, which can result in significant cost savings for homeowners over time.

In addition, modern cold climate air source heat pumps such as variable speed gas/electric units have become increasingly popular due to their increased efficiency when compared with conventional systems.

These high-efficiency models employ Advanced Heat Pump technology which extracts more efficiency from outdoor ambient temperature rather than just providing basic on/off cooling capabilities like standard head pumps do.

In fact, even at outdoor temperatures down as far as -15 degrees Fahrenheit they still operate very effectively while still maintaining efficient operation indoors when operating outside their optimal range between 40F – 90F (5C – 32C).

Reduced Environmental Impact

Using heat pumps instead of traditional boilers or furnaces powered by fossil fuels can significantly reduce greenhouse gas emissions.

According to a study from Berkeley Lab, “choice of heating technology..predominantly affects home carbon dioxide (CO2) emissions” and heat pumps could reduce CO2 emissions in 70% of homes across the country.

Heat pumps are often considered to be one of the most energy efficient methods for both cooling and heating buildings since they take advantage of outside air temperature to regulate indoor temperatures.

Additionally, they don’t burn fuel like other systems do which makes them an environmentally friendly option as well as a cost effective one since you can save up to thousands of dollars each year on your energy bills.

Improved Indoor Air Quality

  • Traditional heating systems can be major contributors to indoor air pollution, as they are designed to simply burn fossil fuels in order to generate heat.
  • Heat pumps feature high-efficiency filter systems that trap airborne irritants such as dust particles, pollen and other allergens which normally circulate through the home when traditional heating systems are used.
  • Proper maintenance of your heat pump system is also important for ensuring optimal filtration power.

Disadvantages Of Heat Pumps In Cold Weather

Heat pumps may not be able to reach the desired temperature when temperatures dip into extreme cold, or require supplemental heating options.

Limited Heating Capacity In Sub-Zero Temperatures

Heat pumps are widely used for home heating, but many people don’t realize that the efficiency of heat pumps decreases when the outdoor temperatures drop. 

Standard air-source heat pumps lose their efficiency as soon as the temperature drops to about -10 degrees Celsius or colder and they can struggle to keep up with extremely cold temperatures below 0 degrees Celsius.

As a result, some homeowners may need an additional source of supplemental heat to provide adequate warmth during sub-zero periods in especially cold climates.

Higher Upfront Costs

One of the major drawbacks of purchasing a heat pump for cold climates is the much higher upfront costs compared to traditional heating options. 

Although there are operational and energy cost savings that come with adopting an air-source or ground-source heat pump.

Initial installation costs can range anywhere from hundreds to thousands of dollar depending on complexity factors such as size, type, labor hours, and system components required.

Heat pumps specifically designed for colder temperatures often offer increased efficiency and performance capabilities which can account for some of those higher upfront costs due to advancements in technology.

The refrigerant coils used in modern cold-climate air source heat pumps are typically thicker than their counterparts built for milder conditions allowing them to capture greater amounts of ambient heat from outdoor air before reaching subfreezing temperatures (under -14°F).

Dependence On Electricity

Heat pumps are powered by electricity, and while air-source models may technically work in colder climate areas, they tend to require more energy to function effectively due to the lower ambient temperatures.

This makes them less efficient in terms of operation costs compared with other heating systems such as oil or natural gas furnaces. 

In addition, extreme cold temperatures can affect the performance of heat pumps, making it even harder for them to pull in enough heat from outside.

To ensure optimal efficiency when using a heat pump during colder months, proper installation and maintenance is essential. Air filters should be regularly replaced.

Snow or debris around the outdoor unit should be cleared away; annual checkups should also help identify any problems before major issues arise and minimize energy consumption from the beginning.

Temperature Range For Effective Heat Pump Operation

A heat pump will generally operate efficiently if the outdoor temperature is above 15 degrees Fahrenheit, although it may be able to run at lower temperatures with some additional heating elements.

Optimal Temperature Range For Efficient Operation

The optimal temperature range for efficient heat pump operation is typically between 30 to 40 degrees Fahrenheit. 

  • Anything below that can start to impede on the performance of air-source and ground-source heat pumps, leading to decreased energy efficiency and increased electricity costs during winter months.
  • A wide range of variables such as outdoor temperatures, wind chill and humidity levels will impact the performance of your heat pump at any given moment.
  • Heat pumps installed in colder climates should also be equipped with variable speed compressors which work better than traditional single stage compressors 

Factors Affecting Heat Pump Performance Outside Optimal Range

Heat pump performance outside of an optimal range can vary greatly, with the most important factor being outdoor temperature. 

Heat pumps are less efficient in extreme cold temperatures and can become completely ineffective at very low temperatures.

Factors such as wind chill, precipitation, and humidity also play a role in heat pump performance when temperatures drop below their respective ranges. 

Wind speeds above 15 mph or heavy rain and snowfall reduce air flow around the unit causing decreased energy efficiency.

The importance of proper installation and maintenance of a heat pump is critical to its performance in colder environments.

Incorrect sizing or inadequate insulation between indoors and outdoors means that the heating system isn’t working optimally even if it’s functioning correctly.

Regular maintenance of your heat pump, including changing air filters, scheduling periodic checkups and cleaning away snow and debris from around the unit are essential for optimal performance in cold weather conditions.

Regular Filter Replacement

It is essential for Heat Pump Owners to regularly replace their filters in order to ensure optimal performance of a heat pump system in cold weather. 

  • Filters should be replaced according to the manufacturer’s instructions, usually once every 90 days or sooner each season depending on use and environment (this may vary).
  • Homeowners should clear snow and debris away from the unit’s outdoor section if it accumulates more than two inches high as it impedes indoor ventilation airflow too.
  • Air filter grills need regular dusting as well so dirt does not collect there either.
  • It’s also important to clean coils via an annual maintenance checkup carried out by an HVAC professional technician.

Annual Maintenance Check-Up

It is essential to keep heat pumps in prime condition year-round, but especially during the colder winter months. 

With an annual maintenance check-up from a certified HVAC technician, homeowners can ensure their system is functioning properly and reduce the risk of breakdowns or costly repairs.

This tune-up includes checking all components of the system, including filters, blower motors, ducts for leaks and obstructions as well as ensuring adequate airflow by measurements.

Clearing Snow And Debris Around The Unit

Here are some key steps that should be taken when keeping the area free of debris and snow:

  • Ensure there is at least two feet of clearance around the entire unit on all sides – including any fences, walls or other objects – to ensure proper airflow throughout the system.
  • When cleaning up, be sure to turn off the power or switch it onto “emergency heat” mode if available.
  • Keep an eye out for ice build – up as well as snow covering any part of the condenser unit as this can restrict air flow.
  • If necessary for heavier snows, shovel away any trapped snow before turning it back on again after cleaning.
  • If your device has a defrosting cycle (as most do), make sure that this function is operating correctly in order to maintain performance levels during colder conditions.
  • The uninterrupted operation helps maintain efficiency levels which are crucial during extreme temperatures when more energy may be needed to generate enough warmth inside homes in cold climates.

Factors To Consider When Selecting A Cold Climate Heat Pump

Choosing the right cold-climate heat pump can be a challenge, but there are several important factors to consider when making a decision. 

Homeowners should take into account their heating needs, type of fuel used in their area, energy efficiency loading requirements, and long-term use before investing in a cold climate heat pump.

Heating needs

When selecting a cold climate heat pump, it’s important to consider the size of your home and the amount of usage you anticipate during colder months. 

Depending on the size of your house and how often you use your heat during winter months, you may need to install one or more units to meet your needs.

Type of Fuel

The type of fuel used in your area will play a role in determining the best type of heat pump for you.

For homes using gas or oil furnaces, electric air source systems are typically best for most climates while ground source systems are better suited for extreme cold weather climates such as Zone 5.

Energy Efficiency Loading Requirements

Heat pumps come with varying levels of energy efficiency ratings that indicate how much heating output is produced per unit of energy consumed.

If you plan on using the unit frequently during periods of extreme cold outside temperatures (e.g., weeks at -15 degrees Celsius) then choosing a higher efficiency rating would be better than opting for minimal power savings over the short-term.

Long-term Use

  • Before making any calls on your new potential purchase, ask yourself questions about overall durability.
  • Considering factors like these can help you make an educated decision reflective of both short-term budgetary needs as well as long-term performance expectations

Dual Fuel System

For those living in particularly severe cold climates such as Zone 5. 

It is recommended that you opt for either air-source or ground-source dual fuel systems which combine electric air and/or ground source heat pumps with fossil fuels like natural gas or heating oil. 

This system provides supplemental backup heating when temperatures drop below what an electric system would normally run at without interfering unnecessarily with energy bills year round.

Enabling homeowners not only peace of mind but also additional energy cost savings over time relative to relying solely on traditional heating sources

Top-Rated Heat Pumps For Cold Weather

When considering the best heat pumps for cold weather, it’s important to take into account the Heating Seasonal Performance Factor (HSPF). 

  • The HSPF measures the efficiency of a heat pump over the entire heating season, with higher numbers indicating better performance. 
  • A high-HSPF heat pump can provide dependable heat even at temperatures below -20°F, making it suitable for cold climate regions. 

Here are some top-rated heat pumps with high HSPF ratings and their benefits for cold weather operation:

Heat Pump ModelMitsubishi Hyper-Heating (H2i)Carrier Infinity 20Daikin Altherma EKHWSU150BTrane XV20i
HSPF Rating13.513.012.510.0
Benefits for Cold WeatherDesigned specifically for cold climates,H2 can provide heating at outdoor temperatures as low as -13°F.Featuring Greenspeed intelligence. This model adapts its output to match the heating needs, ensuring efficient operation.Designed for cold climates, this air-to-water heat pump provides reliable heating and hot water at temperatures as low as -4°F.With variable speed technology, this model maintains consistent heating output and efficiency in cold weather.


How do heat pumps work in cold weather?

Heat pumps use a reversible cycle of refrigerant to transfer heat from the outside air into your home during winter months and from inside your home outwards during summer months. 

The efficiency of the process is determined by the temperature difference between inside and outside, making it more economical for colder climates since warm air contains more potential energy than cold air does.

Are there any disadvantages to using heat pumps in lower temperatures?

When the mercury drops too low, an auxiliary heating element may need to be used along with a heat pump system in order to maximize comfort levels within a space as well as provide sufficient warmth on really frigid days where temperatures dip below 0 degrees Fahrenheit or Celsius depending upon area’s climate type & conditions.

Do I need a special type of heat pump if living in a colder region?

There are certain types of systems that are specifically designed for colder regions such as multi-stage systems which offer variable output that can better adjust heating demands when needed rather than just providing one steady stream at all times ensuring optimal performance & savings potential.

What should I look for when purchasing a new heat pump?

When selecting new equipment you want to ensure proper size/capacity so it seamlessly operates while avoiding overstressed or underperforming components which could lead to costly repairs later down the road due to improper usage/wear & tear due to designed limitations resulting in poor results.


The use of heat pumps in cold weather climates has traditionally been limited by their efficiency when temperatures dip too low. However, advancements in different types of systems and technologies have led to heat pump models with improved performance even at sub-zero temperatures.

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