International. As part of a Joint Sponsorship Agreement, ASHRAE and AHRI have published Standard ANSI/ASHRAE/AHRI 155-2024, Test Method for the Qualification of Commercial Space Heating Boiler Systems.
This standard provides procedures for determining the steady-state thermal efficiency, part-load efficiency, and idle energy input rate of space heating boilers.
ANSI/ASHRAE/AHRI 155-2024 applies to steam and hot water boiler systems (single, modular, or multiple boilers) for use in space heating applications and that have individual boilers or modules with gas, oil, electric, or multiple fuel inlets of at least 300,000 Btu/h but less than 12,500,000 Btu/h. However, it does cover custom-designed boilers assembled in the field.
In addition, the standard provides methods for comparing energy consumption measurements of various boiler systems, although ASHRAE has clarified that it is not intended to provide an absolute measure of performance in any specific installation configuration. The standard includes:
- Test methods for determining the steady-state thermal efficiency at full load and partial load, idle power input rate, and flow loss rate of individual boilers,
- Methods for interpolating and extrapolating test data.
- Qualification conditions to be used in the execution of tests and calculations for a variety of classes of space heating applications.
Other Considerations
This standard applies to the space heating performance of boiler systems used for multiple functions, including space heating.
This standard does not cover boiler system test methods used solely in service water heating applications.
