1. Ron Domitrovic Program Manager, Energy Efficiency Variable Capacity HP Subcommittee 8/28/2013 Load Based Testing for Unitary HVAC

2. 2 © 2013 Electric Power Research Institute, Inc. All rights reserved. Load Based Testing of Variable Systems Psychrometric rating testing is standard for unitary HVAC equipment –80°/67° is accepted as THE standard –Controlled return air conditions –Measured capacity/power/efficiency with system on. Works well for single-speed HVAC systems

3. 3 © 2013 Electric Power Research Institute, Inc. All rights reserved. Load Based Testing of Variable Systems Common standards: –AHRI 210/240: Systems < 65,000Btu/hr –AHRI 340/360: Systems > 65,000 Btu/hr –ANSI/AHRI 1230: VRF systems <300,000 Btu/hr

4. 4 © 2013 Electric Power Research Institute, Inc. All rights reserved. Load Based Testing of Variable Systems –Designed for fair comparison among similar systems –NOT primarily designed for energy calculation However; generally OK with single speed systems Difficulties with variable capacity systems THESE ARE RATING STANDARDS

5. 5 © 2013 Electric Power Research Institute, Inc. All rights reserved. Load Based Testing of Variable Systems –Why? Current standards require fixed operation Fixed operation may not capture actual (field) behavior Systems can be configured for optimal operation (for rating) –May or may not match field operation Energy use is dependant on actual operation

6. 6 © 2013 Electric Power Research Institute, Inc. All rights reserved. Load Based Testing of Variable Systems Load Based Testing –Also called “calorimetric testing” –Load on system is held constant –No fixed control of system under test –ASHRAE TC 8.11 is exploring possibilities –Potentially more appropriate for energy calculation –More difficult—labs are not currently set up for it

7. 7 © 2013 Electric Power Research Institute, Inc. All rights reserved. Together…Shaping the Future of Electricity