Some aspects of the energy cost linked to the IAQ. Impact of free-cooling and heat recovery in office buildings

Increasing air exchange rate to improve IAQ may increase energy consumption, but this increase may be compensated for by strategies such as free cooling and heat recovery. The frame of the proposed paper is the examination of the potential at a regional level (the Iberian peninsula) of the different strategies mentioned above in typical office buildings. Based on a set of reference building morphologies, studies are conducted to evaluate the impact of increasing air ventilation rates for different orientations, quality of the envelope (opaque walls and glazing), operating schedules and indoor set-point temperatures. Then, the impact of the increased air ventilation rates is corrected by introducing the effect of free-cooling, air-to-air heat recovery devices of different types and finally, the combined effect of both energy savings strategies. The research provides Maps allowing: 1. To identify zones when heating or cooling regimes are dominant, in terms of both, peak load conditions and energy requirements. 2. To compare the expected performance of the two energy saving strategies at a certain locality. 3. To compare the potential benefit of applying a given strategy at different localities. 4. To indicate regions of recommendable application of the strategies and the expected energy savings achievable.