Evaluating an active low-energy cooling upgrade to the building envelope in the hot climates of the Middle East[Energy efficiency of residential buildings in the kingdom of Saudi Arabia: review of status and future roadmap]

Reducing cooling loads in hot countries requires thermal insulation, and cooling methods be improved. Evaporative cooling, although problematic, is one solution that can be explored since it is significantly more efficient than regular compressor air conditioners, and the net result of using one is cooling. Furthermore, while compressor air conditioner efficiency decreases with rising temperatures in summer, evaporative ones, up to a point, are the exact opposite. A novel hybrid cooling system capable of combining both showed an 80% decrease in cooling load. The system’s efficacy was assessed in this paper by thermally simulating designs that are suitable for the hot Middle East region. Two locations with different environments and building guidelines that are representative of the variations in the area were selected. The first was the hot, dry Baghdad environment; the other was Dubai’s coastal, more humid city. Two different houses were designed to suit the municipal rules of each and accommodate the hybrid cooling system. As expected, the simulation results showed that savings in the dry Baghdad climate were high at 78% compared to a non-insulated alternative. In Dubai, unsurprisingly, they were less at 52% on the more humid coast. Further simulations revealed that this latter figure in the humid coast could also be achieved using good thermal insulation.