Optimizing thermal comfort and energy use for learning environments

Thermal comfort is a critical component of indoor environments, especially in schools where learning is the main objective. However, thermal comfort comes at a price that many schools are unable to afford. Therefore, it is critical to determine a method to lower the energy costs of a building while still maintaining occupant thermal comfort. The objective of this study is to investigate how three indoor environmental parameters of air speed, humidity, and air temperature influence energy and thermal comfort in classroom environments. We employed a multi-objective optimization method that considers all three thermal parameters in the design and operation of a classroom. This method is demonstrated for three distinct climate locations (very hot and humid, cold and humid, warm and marine). Overall, our findings demonstrate significant energy savings from 1.3 to 9.1 kWh/year/m² for cases where energy reduction is achieved. These values are for cases where the total annual number of hours that more than 10% of people are dissatisfied in a space are 0 to 42 in Miami and San Francisco and 26 to 49 in Boston. This translates to a cost savings of $3,000 to $12,800 per year for the entire building at current market rates. Note that for all locations, there were also cases where the number of hours that more than 10% of people were dissatisfied were reduced from the baseline value while still reducing energy use. This optimization framework shows promise for building mechanical designers seeking to maintain increased levels of thermal comfort throughout the year while lowering energy use.