Reducing Building Energy Costs Using Optimized Operation Strategies for Constant Volume Air Handling Systems

Abstract

Building energy consumption can be substantially
\nreduced after implementing what we call Extended
\nO&M Measures. The Extended O&M Measures are a
\nscientific refinement of traditional O&M measures.
\nSpecifically, they involve resetting the cooling deck or
\nheating deck temperature according to the ambient
\ntemperature such that maximum energy efficiency can
\nbe achieved without compromising indoor air quality
\nand comfort. Extended O&M Measures optimize
\nsystem performance as a whole rather than focusing on
\nthe malfunction of individual component. Our study
\ninvolving five medical and institutional buildings at
\nthe University of Texas Medical Branch (UTMB).
\nGalveston shows that Extended O&M Measures can
\nreduce chilled water and condensate costs by
\n$517,800/yr or 19% of the total building energy cost
\n($2.7 million dollars). This potential percentage
\nsavings is comparable to the LoanSTAR measured
\nthermal energy savings in 10 buildings at another
\nUniversity of Texas campus where constant air volume
\nsystems have been converted to variable volume
\nsystems. Though in the later case fan electricity
\nconsumption is also reduced but with some investment
\ncost. On the other hand, Extended O&M Measures do
\nnot require any retrofit or investment cost. Extended
\nO&M Measures have been implemented in one of the
\nfive buildings, and the measured savings are consistent
\nwith predicted savings. It seems that the Extended
\nO&M Measures are an excellent alternative to
\nconverting constant volume systems to variable
\nvolume systems, especially if there are no retrofit funds available.