simulation

The objective of this paper is to assess the impact of the envelope airtightness on airflow patterns for single detached dwellings depending on the ventilation system.

Detached residential wooden houses are a common type of housing in Japan. Decay of wooden components within the walls is easily caused by condensation or defective flushing. To solve this problem, a double-skin system with a room-side air gap was developed. In this system, during winter, the airflow in the ventilated wall circulates freely around the whole house. Therefore, during daytime, the airflow moves solar heat to base, and releases heat to the house at night which can increase indoor temperature.

Building integrated renewable energy sources e.g. photovoltaic system is one of the promised solution for improving energy efficiency in building. However such kind of the system is restrained by irregular power supplied and necessity to convert current from direct to altering form. Therefore, very often the electrical energy generated by photovoltaic system cannot be effectively utilised to supply building devices, e.g. components of HVAC or lighting system.

In low energy buildings and passive houses due to very low heating demands integrated heating and ventilation (VAV or DCV) systems are used to provide proper indoor climate conditions – thermal comfort and indoor air quality. Dynamic changes of indoor conditions result in permanent changes in air flow.

Passive cooling by night ventilation is one of the most promising approaches to reduce cooling energy demand of office buildings in moderate climates. However, the effectiveness of this system depends on many parameters.

Thermal comfort studies have been performed so far either in closed climate chambers with controlled conditions or non-controlled conditions during field studies. Detailed analyses of mechanisms behind the adaptive comfort models are therefore hardly possible. This paper presents a newly constructed climate chamber in Karlsruhe (Germany) along with the complete chain from subjective experiments, via data analyses, model development and implementation into dynamic building energy simulation until the formation of a decision base for or against a renovation measure for a confined case.

Excess energy consumption of HVAC system is not usually noticed without the dissatisfaction to thermal environment. Recently it has become easier to discover it in buildings with the aid of Building Energy Management System (BEMS). Indoor Air Mixing loss occurs in an office when the perimeter zone is heated by one HVAC system and the interior zone is cooled by the other system. The aim of this study is the quantitative analysis of the mixing energy loss in office buildings. Experiments are conducted in a full-size experiment room.

Over the last three years the understanding, adoption and use of BIM has gained international momentum.

To improve the energy performance of a district heating and cooling (DHC) plant, the expected performance of the plant was studied using simulations based on mathematical models. A model of the entire heat source system with an embedded module that automatically determines the on/off status of heat source equipment using cooling/heating loads was developed and validated using measured actual performance data. The mean error between the simulated and measured total energy consumption was 4.2%.

This study developed a component-based gray-box model for variable refrigerant flow (VRF) airconditioning systems to simulate and predict the performance and energy consumption of VRF system in cooling condition. Results from the testing of Daikin’s 10HP VRV system with six indoor units, as well as the manufacturer’s data, were used to fit the key parameters of each component in this VRF model. This model was integrated in the building energy simulation software DeST and was validated by using data both from Daikin’s product handbook and from tested results.