Energy budget constrained comfort optimization for smart buildings

Abstract

Efficient energy management in buildings is becoming an important requirement aimed at reducing energy costs and environmental pollution. Setting a monthly budget for energy consumption, and consequently energy cost, of buildings is being practiced by several organizations in a bid to reduce their carbon footprint. However, the impact of such an energy budget on the indoor comfort of users in a building has not been paid much attention to. In this regard, we present a constrained optimization model that maximizes the users' comfort while adhering to the budgeted energy consumption of a building. Our energy cost model is based on the temperature difference that has to be bridged by the Heating, Ventilation and Air Conditioning (HVAC) unit to ensure optimal user comfort. We model user discomfort as a function of the difference between the temperature setting of the HVAC unit and the target temperature for user comfort. We derive closed form expressions for the HVAC temperature setting in terms of the fixed energy budget for both heating and cooling scenarios in different types of buildings. Our main contribution is towards budget planning of buildings which aims to achieve a certain degree of indoor comfort as decided by the building operator, at a relatively fixed energy budget.