NIST Time|NIST Home|About NIST|Contact NIST

HomeAll Years:AuthorKeywordTitle2005-2010:AuthorKeywordTitle

Experimental and Simulated Performance of Optimal Control of Building Thermal Storage.


pdf icon Experimental and Simulated Performance of Optimal Control of Building Thermal Storage. (1199 K)
Morris, F. B.; Braun, J. E.; Treado, S. J.

3776;

ASHRAE Transactions, Vol. 100, No. 1, 402-414, January 1994.

Keywords:

storage; building control; experiments; test facilities; simulation; optimal control strategies; energy savings; peak demand reductions

Abstract:

Dynamic building control involves utilizing the thermal storage potential of building mass to reduce cooling costs. Previous simulation studies have shown that both energy use and peak electrical demand can be significantly reduced using dynamic building control instead of conventional night setback control for many applications. In this study, optimal dynamic building control strategies were compared with night setback control through experiments at a test facility representative of a room in a large office building. Two optimal dynamic building control strategies were considered: minimum total energy costs and minimum peak electrical demand. These control strategies were determined through simulation of the test facility. The experiments showed that up to 51% of the total cooling load could be shifted to off-peak hours through optimal control. The reduction in the peak cooling load was found to be as much as 40%. For the test conditions, estimates of electrical energy and demand savings were determined through simulations and found to be 10% and 38%, respectively. Occupant thermal comfort was also measured during the experiments and maintained within acceptable limits for all control strategies tested. Measured cooling loads compare well with those predicted by the simulation and validate the simulation method. Additional simulations were conducted to study the effect of ambient conditions, utility rate structure, and the coupling between the zone and the ambient through exterior walls on the savings potential of dynamic building control. The results of this research demonstrate the tremendous potential associated with optimal control of building thermal storage.