The performance of double skin facades in office building refurbishment in hot arid areas

Abstract

The facade's configuration in hot arid areas is predicted to be responsible for up to 40% of the building's cooling loads. The increasing reliance of public buildings in Cairo on air conditioning systems indicates the failing role of the building envelope to perform its function as a moderator leading to an alarming increase in electricity consumption. Office buildings in Cairo consume 5-7% of the total national energy consumption. The need to reduce energy consumption in this sector targets benefits of reductions of electricity bills to building owners as well as reducing C02 emissions from the built environment due to increasing electricity generation. The lack of maintenance funds left the office building facades in a deteriorated state. This deterioration of image led to abandonment of buildings and loss of economic revenue. Double skin facades were investigated as a novel facade refurbishment option, targeting a multi criteria framework for facade refurbishment set in this thesis. To achieve the aim of the thesis, different facade technologies were simulated using a dynamic software (APACHE v.4.3.1) to understand their thermal performance. Quantitative results of simulations were parametrically examined to identify benchmark options for facade refurbishment to reduce building total cooling loads. Simulations results indicated up to 40% reductions in total cooling loads if a double skin facade with an outer reflective surface is used. Information generated from the simulation of single and double skin facade configurations were inducted into qualitative theories predicting human comfort aspects within the workplace. Three qualitative criteria underpinning the psychological comfort of occupants and its impact on productivity are set for balancing energy saving measures through facade refurbishment. These criteria are: the need for a view out, day light availability for non-task performances, and perceived control over the facade in work places.