Energy saving strategies in the museum environment air conditioning

In the museum environment a strict control of the required values of the thermal-hygrometric parameters is necessary primarily for the correct artwork conservation and then for the visitor thermal comfort. Considering the air conditioning system working twenty four hours per day, during all the year, suitable techniques permit to obtain useful energy savings, allowing, however, the requested microclimatic design conditions on varying thermal loads. In this paper a case-study is presented about the evaluation of the most significant results obtained using various strategies to reduce energy requirements for HVAC systems in an exhibition room of a modern museum. Using the dynamic simulation code DOE 2.2 and hourly climatic data, the annual energy use for an all-air system has been calculated, as well as the saving obtainable using different techniques, such as dehumidification by adsorption (desiccant wheel), total energy recovery from the relief air (passive desiccant), outdoor air flow rate variation (demand control ventilation), enthalpy air economizer. The effects on the thermal-hygrometric indoor parameters have been also evaluated, particularly as regards the dynamic humidity control. Moreover, the correspondence has been analysed between the energy request of the air conditioning system and the admitted variation of indoor temperature and relative humidity.