No abstract

No abstract

No abstract

Building energy savings and occupant thermal comfort are the main issues in building technology. As such, the development of energy-efficient heating, ventilation, and air-conditioning (HVAC) systems and the control strategies of HVAC systems are emerging as important topics in the HVAC industry. Variable refrigerant flow (VRF) systems have efficient energy performance, so the use of VRF systems in buildings is increasing. However, most studies on VRF systems focus on improving mechanical efficiency, with few studies on energy-efficient control while satisfying the thermal comfort of occupants. The goal is to estimate the energy-saving potential of adjusting the temperature set-points and dead-band (range) in VRF air-conditioned building. To do so, we analyzed the influence of control strategies of a VRF system on human thermal comfort and energy consumption using a simulation method. The results showed that energy consumption can be reduced by 25.4% for predicted mean vote (PMV)-based control and 27.0% for the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) comfort range control compared with the typical set-point temperature control of a VRF system. The indoor thermal environments of the analyzed control strategies are controlled in the thermal comfort range, which is based on a PMV at ±0.5. Compared with the typical set-point control, PMV and ASHRAE comfort range-based control reduced the operation time of the compressor in the VRF system.

The number of passive houses and zero-energy buildings being developed is increasing, as measures to reduce the rapidly increasing building energy consumption. While government building policies focus on energy savings, investors and the building market emphasize the initial investment cost. These conflicting perspectives obstruct the development of passive houses in the building market. In this study, a series of building energy analyses, including the effect of energy saving measures and economic information considering long-term economic benefit and incentives policy, will be presented. Analyses were performed on the energy-saving measures needed to improve the performance of single-family houses in Korea to that of the passive house standard, as well as the energy saving effect and increased cost. The application of energy saving measures for passive house implementation resulted in an additional cost of 1.85%–4.20% compared to the conventional reference house. In addition, the proposed passive house alternative shows a short payback period and life cycle cost (LCC) result, compared to a conventional building’s life cycle period. The possibility of passive house implementation is high, and developing the passive house is affordable for the investor or end user in Korea.