Towards development of near zero energy buildings: energy performance optimisation of relocatable prefabricated accommodation (RPA)

Vahid Farahi

Relocatable Accommodation is one of the most common types of prefabricated buildings. These types of lightweight accommodation are rapidly transported to a site as an all-in-one solution offering a high standard of thermal comfort, acoustic, and safety for the occupants, particularly in remote areas (e.g. a mining site) where employing conventional construction methods is not economical. The present study assesses the thermal energy performance of a mining hut (relocatable building) positioned at Murdoch University, Perth campus. The study mainly focuses on the thermal energy performance of the building envelope multi-layer structures in order to introduce an optimized envelope/facade configuration offering a low heat-transfer coefficient (U-Value). Moreover, the latest technological advancements available in Australia's HVAC market have been considered to minimise the space heating/cooling electricity demands. First, the mining hut was fully instrumented, and real-time data, including indoor/outdoor temperature, humidity, noise, and air quality, were collected for both summer and winter seasons. Then, the case study was created and developed in DesignBuilder software, and the accuracy of the model was validated by comparing the measured and predicted data. Following that, numerous simulation tasks were carried out to evaluate the building's annual site-energy demand under different envelope configurations and HVAC systems: modified outer walls, roof, windows, external floors, and air conditioning units. Having analysed the predicted results, the best-performing scenarios were selected to develop the Murdoch University Proposed Model (MUPM). The results indicate substantial impacts of insulation, airtightness, solar heat gains and high-performing air conditioning units on the building's annual energy demand. The software estimates corresponding annual energy savings for upgraded external walls (27.4%), air conditioning units (25.8%), airtightness (9.8%), windows (6.7%), and exterior floors (6.6%), and roof (3.3%) can be individually achieved. Finally, it is predicted that the proposed model, MUPM, could save approximately 48.1% on the Total Site Energy (3,207.87 kWh compared to 6,183.95 kWh) and 67.3% on the annual space heating and cooling electricity demands (456.9 kWh) compared to the base building (1,399.38 kWh). Overall, this research provides an insight into the thermal energy performance of transportable accommodation and the potential areas for saving energy hence providing part of the solution toward near zero energy buildings.

Towards development of near zero energy buildings: energy performance optimisation of relocatable prefabricated accommodation (RPA)

Files and links (1)

Abstract

Details

Metrics