As temperatures drop in New York, homeowners may find themselves asking, “At what temperature do heat pumps become less efficient?” While heat pumps can efficiently heat homes through much of the winter, their overall performance depends on outdoor temperatures, equipment design, and your home’s heating needs.
In this article, the HVAC experts at Suburban Services Group discuss why cold Capital Region winters affect heat pump performance, as well as ways that homeowners can ensure they have the powerful heating they need.
How Outdoor Temperatures Affect Heat Pumps
A heat pump works through thermal transfer, pulling heat into your home from the surrounding outside air. Without the need for combustion, this makes a heat pump a more energy-efficient heat source.
However, as temperatures drop, the heat pump has to work harder to extract sufficient heat to keep your home warm. This means that a heat pump that works well in mild temperatures, may struggle as temperatures near freezing.
When Heat Pumps Lose Efficiency
Performance Below 40 Degrees Fahrenheit
At 40°F, homeowners may begin to experience a decline in overall heat pump efficiency. As the heating demand increases, your heat pump may need to run longer and use more electricity in order to provide sufficient heat. While this doesn’t mean the system itself is inefficient, it can result in higher energy bills in the winter.
Efficiency In Subfreezing Temperatures
Once temperatures drop below 32°F, a conventional heat pump will experience declining capacity and efficiency. This becomes even more significant as temperatures near 5°F and below unless homeowners have a cold-climate model that is designed to maintain greater output and efficiency.
Why Heat Pump Efficiency Drops
Reduced Heat Availability In Cold Air
As temperatures drop, the temperature difference between the outdoor air and the desired indoor air increases. This means that the compressor has to work harder to move heat indoors as the refrigerant must operate at lower evaporating temperatures.
As a result, the system uses more electricity for each unit of heat delivered.
Defrost Cycles And Increased Energy Use
Cold, damp winter weather can cause frost to accumulate on the outdoor coil of the heat pump. This is where the system extracts heat from the air. Since frost restricts airflow and reduces heat transfer, the system must periodically enter the defrost cycle.
During defrost, the system consumes energy to remove frost and, as a result, your electrical consumption will increase.
Cold Climate Heat Pump Performance
Standard Versus Cold Climate Heat Pumps
Not all heat pumps are designed to handle New York winters. Luckily, there are cold-climate models on the market that use technologies to preserve both heating output and overall efficiency, even as temperatures drop below 40°F.
This technology includes variable-speed inverter compressors to ensure you have the heat you need in subfreezing weather without breaking the bank.
Understanding Heating Capacity And Efficiency Ratings
To find the right system for your home, you’ll want to compare the following:
- HSPF2: Heating Seasonal Performance Factor 2 estimates seasonal heating efficiency.
- COP: Coefficient of Performance indicates how many units of heat the system delivers per unit of electricity consumed. Homeowners can look at the COP at 5°F to compare cold-weather performance.
- Heating capacity: A cold-climate heat pump should maintain at least 70% of the system’s rated capacity at 5°F.
When Supplemental Heating Becomes Necessary
Supplemental heating, often a gas or propane furnace, can give homeowners peace of mind that they’ll have the powerful heat they need in freezing temperatures. Homeowners often need this backup when:
- Outdoor temperatures often fall below the system’s effective operating range
- The heat pump is undersized
- The home has air leaks or poor insulation
Ways To Improve Heat Pump Efficiency
To keep your system working efficiently throughout the year, homeowners can:
- Schedule annual heat pump maintenance
- Change filters regularly
- Keep the outdoor unit free of snow and debris
- Seal drafts in the home or improve insulation
- Set a consistent temperature in the home
Get Professional Heat Pump Assistance
When you need quality heat pump service in Burnt Hills, trust the team at Suburban Services Group. With over 45 years of industry experience, our team is proud to service 14 counties in New York State, Vermont, and Massachusetts. With highly-trained technicians standing by, we offer 24/7 emergency service to prioritize your total comfort.
Call Suburban Services Group today to schedule heat pump services in Ballston Lake.
