Efficient Residential Indoor Thermal Environment Control

In this article, recent developments on the efficient control of residential indoor thermal environment are reported. Firstly, fundamental issues for indoor environmental control in residences are discussed. This is followed by presenting an analysis of a number of current control issues for direct expansion (DX) air-conditioning (A/C) systems, including the capacity control, humidity control, and the inherent operating characteristics of a DX A/C system. A number of studied efficient control strategies for simultaneous controlling indoor air temperature and humidity using a DX A/C system, including direct digital control (DDC)-based control, multi-input multi-output (MIMO) control, and artificial neural network (ANN)-based control, are reported subsequently. Finally, some other related issues on residential indoor thermal environmental control using DX A/C systems, including a novel indoor humidity control algorithm (H–L (high–low) control algorithm), capacity control of multi-evaporator air-conditioning (MEAC) systems, and A/C for sleeping environments in the tropics and subtropics are discussed. It is expected that with the improvement on indoor thermal environmental control in residences, occupants' thermal comfort can be improved and more importantly, the energy use for A/C residential buildings reduced. This would in turn help reduce energy consumption in buildings, and thus carbon emission, contributing to sustainable development. Keywords: indoor thermal control; residential buildings; energy efficient; dehumidification