Paper Conference

2018 Building Performance Analysis Conference and SimBuild co-organized by ASHRAE and IBPSA-USA

     

A QUICKER METHOD FOR DETERMINING THE UA-VALUE OF A RESIDENTIAL BUILDING

Tony Chen

Abstract: The present study on determining the UA-value of a residential building is based on a simple heat-balance approach. It is quicker than any traditional long-term insitu measurement method. The supply and return air temperatures, the relative humidity of the heating and cooling system, and the outdoor ambient temperature were measured overnight, allowing the UA-value to be calculated from the system's on and off time periods. In addition to temperature loggers, two HFP01 heat-flux plates by HukseFlux ® and two HFS-3 thin-film heat-flux sensors by Omega ® were employed in this study. Both sensors were calibrated using commercially available polystyrene insulation sheathings with R-values of 1, 3, 5, 10, 15, and 20 hr-ft 2-F/Btu as standard references. The total UA-value was found to be 830 ± 10 Btu/hour-F (or a thermal index of 6.1 ± 0.1 Btu/ft 2-F-day) by using the heat-balance method for this 3,290 ± 5 ft 2 house located at latitude 38N and longitude 78W, inland of Zone 4. This value was then compared to the in-situ measured UA-value of 800 ± 10 Btu/hour-F and a retracted UA-value of 840 ± 20 Btu/hour-F based on the house's 10-year average electricity consumption data, known as the Degree-Day Method.
Pages: 565 - 572
Paper:
simbuild2018_C077