Heat pumps have become a popular choice for energy-efficient heating and cooling, but their performance in cold climates often raises questions among architects and engineers. Understanding extended heating performance is key to selecting the right heat pump for projects in regions with extreme temperatures.

This article explores the options available for cold climates and provides insights into interpreting extended heating performance tables to make informed decisions.

Why Heat Pumps are a viable option in Cold Climates

Heat pumps provide dual functionality for heating and cooling, using electricity instead of fossil fuels. Advances in technology have improved their efficiency and reliability, even in below freezing temperatures. Their key benefits include:

• Energy Efficiency - Heat pumps can deliver up to three times more energy than they consume. This contrasts with electric resistance (baseboards) which are “only” 100% efficient with energy consumed and useful heating output.
• Sustainability - With the adoption of low-GWP refrigerants, heat pumps align with global efforts to reduce carbon emissions.
• Cost Savings - Reduced energy consumption translates to lower operational costs over the system’s lifespan.

However, not all heat pumps perform equally in extreme conditions. That's why knowing where to find and interpret extended heating performance tables becomes crucial.

What is Extended Heating Performance?

Extended heating performance refers to a heat pump's ability to maintain its heating capacity as outdoor temperatures drop. Manufacturers provide performance tables that detail the system's heating output at various ambient temperatures, helping engineers and contractors evaluate suitability for their specific climate zones.

For example, a 9,000 BTU/Hr Samsung WindFree™ 3.0e Wall Mounted Split might offer a rated capacity of 11,000 BTU at 47°F but still deliver 8,000 BTU at -5°F. This reduction in capacity can be easily overlooked when picking equipment.

How Can You Evaluate Extended Heating Performance?

1. Understand the Design Load
   Identify the heating requirements of the building or space. Ensure the selected heat pump can meet the design load at the lowest expected outdoor temperature.
2. Analyze Performance Tables
   Compare the heating capacity at the specified outdoor temperatures. Look for systems with robust capacity retention as temperatures approach freezing or below. Be sure to consider your area's design ambient temperature. If you need assistance finding these tables, please reach out to your RSL sales representative.
3. Efficiency Ratings
   Check HSPF2 (Heating Seasonal Performance Factor) and COP (Coefficient of Performance) to ensure the system is efficient under typical operating conditions. This is useful for comparing differences between manufacturers as well.
4. Consider Supplemental Heating
   In some climates and situations, supplemental heating may be required. Ensure the heat pump integrates well with additional systems, such as electric resistance heaters, hydronic coils or gas heat backup. Knowing how best to control supplemental heat (aux heat lockout above a certain ambient temperature, or compressor lockout below a certain ambient temperature), and confirming the equipment selected can control to this requirement is also important.
5. Surrender Temperatures in Heating Mode
   Some manufacturers will have a “surrender” temperature in heating mode. An example of this is as the ambient temperature drops below the heat pump's lower end ambient temperature rating, the unit would shut off and not come back on until the ambient temperature has risen above the minimum ambient temperature its rated for. Check with your RSL sales representative to ensure that your unit would perform satisfactorily.

Contact Us

Modern heat pumps are redefining how primary heating is accomplished in cold climates, but choosing the right system requires careful analysis of extended heating performance.

For any further enquiries into Heat Pumps, you can contact your local branch to ask any questions you may have. Alternatively, you can email the RSL Online Sales team, and your query will be passed on to the relevant department.