What is HSPF Mini Split: A Comprehensive Guide

A mini-split system is a type of air-source heat pump that is commonly used for heating and cooling homes. One important factor to consider when choosing a mini-split system is its Heating Seasonal Performance Factor (HSPF) rating, which measures the efficiency of the system during the heating season.

Understanding HSPF Ratings

The HSPF rating is a measure of the total heating output of a heat pump during the normal heating season, as compared to the total electricity consumed during the same period. It is expressed in BTU per watt-hour (BTU/Wh). The higher the HSPF rating, the more efficient the heat pump.

As of January 1, 2023, the U.S. Department of Energy (DOE) requires all split system heat pumps to have an HSPF2 of 7.5 or higher, and all single-packaged heat pumps to have an HSPF2 of 6.7 or higher. This is a change from the previous HSPF rating system, which used a single value to represent the heating efficiency of a heat pump. The new HSPF2 rating system is more accurate and takes into account the different ways that heat pumps are used in different parts of the country.

HSPF2 Ratings Explained

The HSPF2 rating is a more accurate measure of a heat pump’s heating efficiency compared to the previous HSPF rating system. The HSPF2 rating takes into account factors such as:

  • Outdoor temperature variations: The HSPF2 rating accounts for the different heating requirements in different climate zones, ensuring that the efficiency rating is more representative of the actual performance of the heat pump in a specific region.
  • Partial load conditions: The HSPF2 rating considers the heat pump’s performance under partial load conditions, which are more common in real-world usage scenarios.
  • Defrost cycles: The HSPF2 rating includes the energy consumption and performance impact of the heat pump’s defrost cycles, which are necessary to maintain efficient operation in cold weather.

By considering these factors, the HSPF2 rating provides a more comprehensive and accurate representation of a heat pump’s heating efficiency, allowing consumers to make more informed purchasing decisions.

Choosing the Right Mini-Split System

what is hspf mini splitImage source: Flickr

When shopping for a mini-split system, it is important to consider the HSPF2 rating, as well as the system’s size and capacity. A system that is too small may not be able to provide enough heat during cold weather, while a system that is too large may cycle on and off frequently, which can reduce its efficiency and shorten its lifespan. An HVAC professional can help determine the correct size and capacity of a mini-split system for a particular home.

Factors to Consider When Selecting a Mini-Split System

  1. HSPF2 Rating: Look for a mini-split system with a high HSPF2 rating, as this indicates a more efficient heating performance. The minimum HSPF2 rating required by the DOE is 7.5 for split system heat pumps and 6.7 for single-packaged heat pumps.

  2. System Size: Ensure that the mini-split system is properly sized for your home. An oversized system will short-cycle, leading to reduced efficiency and increased energy consumption. An undersized system may struggle to maintain the desired temperature, especially during extreme weather conditions.

  3. Cooling Efficiency (SEER): In addition to the HSPF2 rating, consider the Seasonal Energy Efficiency Ratio (SEER) rating, which measures the efficiency of the system during the cooling season. Look for a high SEER rating to maximize energy savings.

  4. Zoning Capabilities: Mini-split systems often offer zoning capabilities, allowing you to control the temperature in different areas of your home independently. This can improve overall comfort and energy efficiency.

  5. Noise Level: Pay attention to the noise level of the indoor and outdoor units, as this can impact the overall comfort and livability of your home.

  6. Warranty and Maintenance: Investigate the manufacturer’s warranty and recommended maintenance schedule to ensure long-term reliability and performance of your mini-split system.

Integrating HSPF2 Ratings into Your Mini-Split System Selection

When evaluating mini-split systems, the HSPF2 rating should be a primary consideration, as it directly impacts the system’s heating efficiency and your energy costs. Here are some tips for incorporating HSPF2 ratings into your decision-making process:

  1. Understand the HSPF2 Rating Scale: The HSPF2 rating scale ranges from 6.7 to 13.0, with higher values indicating more efficient heating performance. Aim for a mini-split system with an HSPF2 rating of 7.5 or higher to meet the DOE’s minimum requirements.

  2. Compare HSPF2 Ratings Across Brands and Models: Research and compare the HSPF2 ratings of different mini-split systems to identify the most efficient options that fit your budget and home requirements.

  3. Consider Climate and Usage Patterns: The HSPF2 rating is particularly important in regions with long, cold winters, as the heating efficiency will have a more significant impact on your energy bills and overall comfort.

  4. Consult with HVAC Professionals: Work closely with HVAC professionals to ensure that the mini-split system you choose is properly sized and configured to maximize the benefits of the HSPF2 rating in your specific application.

  5. Factor in Lifecycle Costs: While the initial cost of a mini-split system is important, also consider the long-term energy savings and reduced operating costs associated with a higher HSPF2 rating, as this can provide significant financial benefits over the system’s lifespan.

By understanding and prioritizing the HSPF2 rating when selecting a mini-split system, you can ensure that your home heating and cooling solution is both energy-efficient and cost-effective, ultimately contributing to a more sustainable and comfortable living environment.


In summary, the HSPF2 rating is a crucial factor to consider when choosing a mini-split system for your home. By understanding the HSPF2 rating system, evaluating the size and capacity of the system, and considering other important factors such as SEER rating and zoning capabilities, you can make an informed decision that will provide efficient and reliable heating and cooling for your home.

Remember, working with an HVAC professional can help you navigate the selection process and ensure that the mini-split system you choose is the best fit for your specific needs and requirements.


  1. Trane – What is HSPF?
  2. ECI Comfort – HSPF Rating: What the Heck is That?
  3. Jacobs Heating – HSPF Rating: What You Need to Know
  4. U.S. Department of Energy – Minimum Efficiency Standards for Heat Pumps