Developing an indoor environment quality tool for assessment of mechanically ventilated office buildings in the UK – A preliminary study

Abstract This study describes the development of a new model for rapid assessment of Indoor Environment Quality (IEQ) in air-conditioned office buildings in the UK using design, measured, calculated and surveyed input data. The novelty of this model is that it addresses the need to present indoor environment performance ratings alongside energy performance certification and help determine by how much energy efficiency imperatives sacrifice human comfort. The model is based on the IEQ index which was developed from literature. The IEQ index is an expression which was derived from four contributing factors namely Thermal Comfort, Indoor Air quality (IAQ), Acoustic Comfort and Lighting. The relative weightings of each of the contributing factors were derived by fitting a multiple regression model to questionnaire data obtained from 68 occupants of two selected case study buildings in the UK. During questionnaire administration, measurement of indoor environment variables such as air temperature, relative humidity, air velocity, illuminance, CO 2 concentrations and A-weighted sound pressure level was carried out in order to validate occupant responses. An empirical expression more suited to the air-conditioned offices in the UK was developed and the end result was a computer based program called the Indoor Environment Quality Assessment Tool (IEQAT). The model was compared to the AHP developed by Chiang et al. and the models showed good agreement.