MOISTURE CONTROL AND ENERGY CONSERVATION IN EXISTI

By nature books will deteriorate with time. In an environment with higher temperatures and relative humidities the deterioration process can be accelerated . For example mould will easily grow at a high relative humidity condition, whereas very low humidity will make stationery material brittle. Therefore, outside air needs to be handled by a dehumidification or a humidification processing before entering the building. The climate in New Zealand is humid. Relative humidity in large cities, such as Wellington , Christchurch and Invercargill can be higher than 85%, whilst in Auckland it can be 100%. Even in February , for the Auckland location. Which has the lowest monthly average relative humidity(rh), rh is at 73%. The control of moisture is a critical problem for library storage. Unfortunately many tertiary libraries in this country were short of money when they were built, co energy systems which were chosen then may not be adequate for this purpose.

The adequate condition for book storage, according to current design options, is at a range of relative humidity 50%± 10% and temperature of 20±2℃. For full control of indoor rh in this range, in Auckland , a HVAC systems which were chosen then may not be adequate for this purpose.

The adequate condition for book storage, according to current design options, is at a range of relative humidity 50%±10% and temperature of 20±2℃. For full control of indoor rh in this range, in Auckland, a HVCR system such as the Dual Duct Fan System (DDS of DDE-2) is needed. With this system, the energy consumption will be doubled compared with a Heating and Ventilating (only) System (HVSYS of DOE-2). By extending the relative humidity range to 30-75%, the conditions suggested by some professionals as acceptable for material storage , energy consumption will be significantly reduced. In analysis of energy perfrmance and conservation, this paper uses a generalised DOE-2 simulation model to compare energy consumption with the two different systems and discusses the relevant problems.