Design and performance evaluation of a smart construction module to improve building energy efficiency

The objective of this research was to develop an energy efficient construction module for the next generation of buildings and shelters. The best possible module design should have the ability to change the direction of heat flow to accommodate both heating and cooling. The heat capacity and surface radiation absorptivity of the module should also be adjustable to transfer and/or absorb the maximum solar energy to optimize its performance under various weather conditions.;In this study, the feasibility of using a prototype module to improve energy efficiency of building envelopes was examined. One or more thermal diodes were incorporated to alter the direction of heat flow in order to provide adequate heating and cooling. To optimize diode design, the diodes were numerically and experimentally compared. Both analyses indicated that installing a long symmetrical guide vane improved the diode's heat transfer performance. After the optimization was made, a bayonet type thermal diode was developed. This bayonet thermal diode showed a thermal efficiency of about 50%, among the highest efficiencies for single phase thermal diodes.;Two storage sheds were set up in Salt Lake City, Utah for one year to study module efficiencies under various weather conditions. The prototype module was installed in one of the sheds, which is referred to throughout this research as the modified shed. The unaltered shed is referred to as the unmodified shed. Temperature variations within each shed were collected and compared.;The results show appreciable energy savings when the module is used for winter heating. An area equal to one half of the south facing door (hereafter referred to as the south facing wall) of 12.2 ft;The module was simple to construct and can be mass-manufactured, thus lowering the cost. It also can be shipped easily and assembled at construction sites. In addition, several modules can be connected together and controlled by a single microprocessor; one master module with temperature and radiation sensors oversees the entire operation under various weather conditions.;Because of the small volume of the shed and its geometric constraints, only three diodes were used during the cooling test. The results in the summer cooling show fewer significant improvements. Nevertheless, test results from both summer cooling and winter heating indicate that installation of the module can reduce annual energy saving costs by 50% or more, with a payback time of 4 to 6.5 years.