Buildings consume over 40% of the total energy in the U.S. Over 90% of the buildings are less than 50,000 square feet in size. These buildings currently do not use building automation systems to monitor and control their building systems. This lack of control generally results in wasted energy and increased operating expenses. So, if money can be saved, why isn’t everybody gaining control of these buildings mechanical systems?

The answer is also money; it costs too much to fix this problem through an energy efficiency retrofit. The Harvest Seasonal Grill testbed was developed to demonstrate that by using web enabled thermostats and HVAC system knowledge, an effective multiple-input and multiple-output (MIMO) control algorithm can be developed that saves energy at a low installed cost.

Driving down the cost of building rooftop package HVAC control systems is now achievable by using internet-connected accessible thermostats and software.

A multiple-input and multiple-output (MIMO) control algorithm has been developed providing predictive control of multiple RTUs providing conditioned air to a single space.

Adding RTU measured power to the MIMO control algorithm creates the ability to optimize multiple RTUs by managing runtime of high efficiency systems versus lower efficiency systems while maintaining space temperatures.

The future will offer small and medium sized buildings a modest cost connected solution combining optimization and demand response.

Related Publications

1. Kim, D., Braun, J.E., Cai, J., and Fugate, D.L., “Development and Experimental Demonstration of a Plug-and-Play Multiple RTU Coordination Control Algorithm for Small/Medium Commercial Buildings,” In Review, Energy and Buildings, 2015.
2. Kim, D., Braun, J.E., Cliff, E., and Borggaard, J., “Development, Validation and Application of a Coupled Reduced-Order CFD Model for Building Control Applications,” In Review, Building and Environment, 2015.