Qatar Thermal Comfort Standard (QTCS): Maximizing comfort to minimize overcooling and energy waste

Our vision is to reduce 11% of Qatar’s total electricity demand by eliminating wasteful “overcooling” in buildings, through the development of a Qatar-centric thermal comfort standard. Energy demand for air-conditioning in buildings is directly responsible for 36% of Qatar’s electricity consumption. This suggests that a substantial reduction in cooling demand would significantly contribute to a reduction of overall energy consumption. Unfortunately, not only is the demand for air-conditioning expected to increase due to an aggressive population growth rate of 5% p.a., there is now evidence that around 30% of the supplied cooling is unwanted by building occupants and hence wasteful. This evidence has emerged through field-work in Qatar undertaken by members of this team at Bath as well as others in Qatar, which shows that the internal temperature set-points chosen in buildings are significantly lower than the temperatures occupants find comfortable – and are hence “overcooled”. This often results adverse occupant responses to counteract overcooling such as increasing clothing insulation or, even worse, the use of personal heaters which further increase energy demand. Evidence is also emerging of the negative health impacts of excessive air-conditioning and frequent transitions between conditioned and non-conditioned spaces, popularly termed “air-conditioningitis”. Thus, “overcooling” can be defined as the creation of occupant thermal discomfort through excessive air-conditioning. This phenomenon is driven by (i) the use -- or misuse -- of imported comfort standards (e.g. the American ASHRAE Standard 55) without due consideration of local culture or needs (ii) lack of occupant control over indoor conditions due to centralized or community-level cooling management (iii) oversizing of chillers, poor commissioning, poor humidity control and (iv) availability of energy that is free at the point of use, which results in low user engagement. An obvious solution to this problem is an upward adjustment of the cooling set-point within buildings. However, it is presently unknown as to what temperature is likely to be found comfortable in Qatar by over 90% of building occupants, i.e., to guarantee a maximum discomfort of

Hamad Bin Khalifa University (HBKU)