A Joint Electrical and Thermodynamic Approach to HVAC Load Control

Building energy management (BEM) systems can shift the heating, ventilation, and air conditioning (HVAC) demand of buildings in summer using pre-cooling. The physical and operational constraints of buildings directly impact the operation of low voltage networks (LVNs). There is a gap in the literature on the extent of the electricity consumption and the voltage profiles of LVNs are influenced by different wall constructions of BEM-enabled buildings. In this paper, a joint electrical and thermodynamic model is used to control residential BEMs, taking into account the constraints of the LVN and the buildings. As a case study, the electricity demand of an IEEE LVN with 55 residential buildings are modeled using four common wall constructions: 1) timber clad; 2) brick veneer; 3) reverse brick veneer; and 4) double brick walls. The results show the buildings with higher access to thermal inertia from inside provide enough thermal storage capacity to shift the entire peak-time cooling demand to off-peak periods. Furthermore, the location of a building in LVN affects its HVAC load shifting, with houses farthest from the transformer starting pre-cooling earlier to avoid exceeding the voltage limit. This paper shows the advantage of the joint electrical and thermodynamic model in capturing both the dynamics of HVAC demand for buildings and the electrical dynamics of LVN.