Testing and evaluation of line-voltage thermostats. Final report
- GEOMET Technologies, Inc., Germantown, MD (United States)
Two manufacturers have developed new low-cost and high-performance electronic line-voltage thermostats with funding from the Electric Power Research Institute (EPRI)These new thermostats offer the potential for improved thermal comfort and energy savings compared to conventional bimetallic line-voltage thermostats. To verify the performance, EPRI retained GEOMET Technologies, Inc., to conduct tests of these electronic thermostats and conventional bimetallic thermostats in the controlled environment of their laboratory research house during the heating season of 1992--1993. The test data were analyzed to evaluate space heating energy consumption and thermal comfort as a function of the type of thermostat. The analysis of measured results found no significant difference in space heating energy consumption that could be attributed only to the type of thermostat tested in the controlled environment of the research house. However, potential energy savings of up to 28 percent were estimated assuming the behavior of an occupant that used the improved thermal control characteristics of an electronic thermostat to lower the average temperature setpoint while maintaining an equivalent minimum level of thermal comfort. Overall, the electronic thermostats provided better thermal control with a smaller temperature deadband, higher cycle frequency and less droop compared to the bimetallic thermostats. Steady state comfort calculations indicated that while electronic thermostats generally provided better comfort levels than the bimetallic thermostats, in some cases, the conventional bimetallic thermostat provided the same comfort level as an electronic thermostat. However, the bimetallic thermostats often failed to satisfy comfort criteria based on the magnitude and frequency of temperature variations whereas the performance of most of the electronic thermostats satisfied these transient comfort criteria.
- Research Organization:
- Electric Power Research Inst., Palo Alto, CA (United States); GEOMET Technologies, Inc., Germantown, MD (United States)
- Sponsoring Organization:
- Electric Power Research Inst., Palo Alto, CA (United States)
- OSTI ID:
- 10137616
- Report Number(s):
- EPRI-TR--103805; ON: UN94009144
- Country of Publication:
- United States
- Language:
- English
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