Submitted by Maria.Kapsalaki on Tue, 03/22/2016 - 09:08
Using solar heat energy has been paid attention to as effective natural energy use. In this study, we deal with air-based solar heat system, which is used for not only ventilation but heating and hot water supply by hot air.
Submitted by Maria.Kapsalaki on Thu, 06/26/2014 - 16:56
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.
Submitted by Maria.Kapsalaki on Thu, 06/19/2014 - 16:49
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.
Submitted by Maria.Kapsalaki on Wed, 06/18/2014 - 15:03
Velocity fields on the platform area and flow rate of the smoke extraction system were experimentally measured under the different fan-operation modes in an actual subway station in Beijing. The velocity at the four tunnels connected with the station and velocity at the stairs between platform and concourses were obtained. Through simulation based on the measured results, the smoke velocity, temperature and concentration in case of station fire under the different fan-operation modes were analysed, and the optimal smoke extraction mode was proposed.
The thermal performance of the building envelope is mainly required for guaranteeing a comfortableand hygienic interior climate. A roof is a part of the building envelope which provides protection from thethermal damage of the sun. To improve this protection ability, we can consider using a ventilated roof,which has a ventilation layer known as a cavity, beneath the roof cover panel.The objective of this study is to evaluate the influence of such factors as the slope of the roof, size orshape of the openings (i.e.
The groundwater heat pump (GWHP) system is an open-loop system that draws water from a well orsurface water, passes it through a heat exchanger and discharges the water into an injection well ornearby river. By utilizing the relatively stable temperature of groundwater, this system can achieve ahigher coefficient of performance and offers a more energy-saving solution than the conventionalair-source heat pump (ASHP) system. On the other hand, its performance significantly depends on thecharacteristics of the groundwater and the underground thermal properties.
In 2000, the domestic greenhouse gas emission in Japan was 1332 million tons of CO2, whichincreased by 8% in comparison with that of 1990. According to the Kyoto Protocol to the United NationsFramework Convention on Climate Change (COP3) held in December, 1997, Japan is obliged toreduce CO2 by 6%, compared with 1990. As a result, Japan is required to reduce by 14% (172 milliontons) on average during the period between 2008 and 2012. Particularly the emission in theresidential/commercial sector in 2000 was on the increase by 21.3%, compared with that of 1990.
As highly insulated and airtight houses have built popularly, the problem which indoor air becomes lowhumidity in winter, is paid attention. The problem is caused by rise of heating level and increase ofventilation amount by mechanical ventilating equipments, etc.1)Then, to clarify the actual condition of indoor low humidity in winter, we monitored the actual humidityenvironment in 29 occupied houses in the Tohoku region and Niigata, Japan, from 2001 to 2006. As theresult, it is found that the indoor low humidity in winter is a common problem regardless of the housecondition.
Because we spend most of our time in enclosed spaces, thermal comfort of buildings rose increasinglyand then energy consumption correspondingly is increased, aggravating the pollution of naturalenvironment. Integrating phase change materials (PCM) into building walls is a potential method ofreducing energy consumption in passively designed buildings. However, there is a strong need forexperimental data to evaluate the capacity of PCM to stabilize the internal environment when there areexternal temperature changes and solar radiations: that is the purpose of our article.