What is TSPR?

Total System Performance Ratio (TSPR) is a performance-based compliance path for HVAC systems which is defined as:


The ratio of the sum of a building's annual heating and cooling load in thousands of Btus to the sum of the annual carbon emissions in pounds from energy consumption of the building HVAC systems.  


The online TSPR analysis tool may be used to enter geometry, envelope and HVAC system inputs to create a building energy model that will estimate the HVAC annual energy use and carbon emissions to generate a proposed TSPR that will be compared against a baseline TSPR to determine compliance. The baseline TSPR is generated automatically by replacing the HVAC system entered into the tool with the baseline HVAC system as defined by the 2018 Washington State Energy Code, Appendix D.


Compliance via the TSPR approach is required for systems serving office, retail, library and education occupancies in all buildings which are also subject to the requirements of WSEC Section C403.3.5 without exceptions. Those HVAC systems are required to comply with the mandatory and prescriptive requirements specified in WSEC Section C403 and WSEC Appendix D, ‘Calculation of HVAC Total System Performance Ratio.’


For example: For a school building, assembly occupancies such as auditorium and gyms are not subject to TSPR requirements, only educational occupancies such as classrooms which are also subject to WSEC C403.3.5 are required to comply with TSPR.


How does TSPR show compliance?

To comply with the 2018 Washington State Energy Code, the proposed system TSPR must be greater than or equal to the baseline system TSPR and meet all other prescriptive code requirements.



The TSPR tool will generate a pdf report documenting the inputs and the TSPR of the both the proposed and baseline system that may be provided to code officials to demonstrate compliance.


Getting Started

To access the TSPR tool, log in to Asset Score (https://buildingenergyscore.energy.gov) and navigate to TSPR.  To create a building, enter inputs and generate a TSPR report, follow the steps outlined on the Getting Started page of this guide.   

 

Where to go for Help 

To assist with data entry, each screen has a Help icon that links to online User Guide help screens. An Asset Score Help Desk is also available to submit a support ticket to request additional assistance.