Boiler Research Project Final Report in Support of ASHRAE Standard 155P

• • This is the final report for boiler research performed at UL Toronto and Intertek Cortland New York laboratories in support of publication of ASHRAE Standard 155P, “Method of Testing for Rating Commercial Space Heating Boiler Systems.” Standard 155P will rate the performance of commercial boilers at part load conditions (where most boiler operate most of the time) and at realistic entering water temperatures. AHRI 1500 is the current standard used by the industry but it only rates boilers at full load and only at unrealistically low entering water temperatures. Standard 155P will allow engineers, manufacturers, owners, policy makers, simulation software developers and others to objectively evaluate and compare the true performance of boilers. This will lead to better HVAC designs, better boiler designs, better utility incentive programs, better energy codes, etc.—all of which will lead to significant natural gas savings and emissions reductions.
  • The primary goal of this boiler research has been to support the Standard 155P Committee in identifying and addressing any technical questions with Standard 155P. Phase I and II of this boiler research was completed at PG&E’s Applied Technology Services (ATS) in 2012.
  • The research included running the 155P method of test on 5 boilers covering a range of boiler types.  In addition to running the tests required by 155P, many additional parametric tests were run to identify potential opportunities to improve consistency of test results.  For example, several tests were repeated at the extremes of the allowable room temperature and humidity.
  • The testing led to many recommendations to improve the clarity, accuracy, and flexibility of Standard 155P.  Most of these recommendations were subsequently incorporated into 155P by the SSPC.  Examples include modifying the minimum duration of the idling test to account for boilers that cycle rapidly and changing the idling test flow rate from the maximum flow rate to the minimum flow rate in order to allow boilers with internal control valves to successfully run the idling test.

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ASHRAE Standard 155P, commercial boiler, condensing boiler, non-condensing boiler,  commercial space heating, commercial HVAC, AHRI 1500, ASHRAE Guideline 36, test procedure, method of test, part load performance, entering water temperature, combustion efficiency, thermal efficiency, jacket losses