Abstract:
A dedicated make-up air unit (DOAS) is a device that supplies outdoor air from outside into large building to meet the requirements of ventilation standards. It is also used to pressurize the building and remove building latent load. So far, there are many buildings in Bangkok that using them and many more will be using them in the near future. Preliminary study has shown that the design and selection for the appropriate DOAS for Bangkok is not quite straightforward. This is because these DOAS have many possible internal configurations and their energy consumption is large. The objective of this research is to design the DOAS that suitable for use in four typical types of building in Bangkok, i.e., office buildings, department stores, hotels, and hospitals. The design will be done by constructing 9 DOAS models for each building type and run them through the energy simulation program (EnergyPlus) to obtain the yearly energy consumption for comparisons. The suitable internal configurations for each DOAS model are considered from all the possible devices, i.e., cooling coil, heat pipe, run around coil, sensible wheel, passive desiccant wheel or enthalpy wheel, and active desiccant wheel. The simulation results show that the suitable configurations of DOAS for office buildings, department stores and hotels consist of a enthalpy wheel, a run around coil, and a cooling coil. The results show the reduction of around 15-30% energy consumption from the traditional cooling coil-only DOAS. For the hospital building, the passive desiccant wheel and the sensible wheel could not be used due to the possible contamination of the exhaust air. Therefore, the only possible configuration for this case is the combination of a cooling coil and a run around coil. The reduction in energy consumption is only around 10%