PR2019

Buildings represent approximately 40% of global energy demand and heat loss induced by uncontrolled air leakage through the building fabric can represent up to one third of the heating load in a building. This leakage of air at ambient pressure levels, is known as air infiltration and can be measured by tracer gas means, however, the method is disruptive and invasive. Air infiltration models are a non-disruptive way to calculate predictive values for air infiltration in buildings.

This study used a mathematical model to explore the accuracy of extrapolating multi-point blower door test results down to lower pressures at which building infiltration usually occurs naturally.  The mathematical model was applied to leaks of five different widths.  The leakage of the five different widths was then combined in different distributions to simulate total building leakage.  The calculated total building leakage was then compared to an extrapolation from the test pressures using a power law curve fit.

The impinging jet ventilation system (hereinafter referred to as IJV) has been proposed as a new air conditioning ventilation system. Properties of indoor environment with this system using impinging jet are complicated. The present paper reports fundamental properties of indoor air with distributed interior heat generation load assuming an office. The experiment was conducted in the climate chamber of which floor area was 27.0 m2, and basic properties of temperature and CO2 distributions were investigated.

Ventilative cooling can be used as a passive cooling measure to reduce the cooling energy demand of buildings. It can be used during the day, directly removing excessive heat gains, or during the night (i.e. night flush), in which cold outdoor air flows through the building and cools down the indoor air volume and subsequently the thermal mass of the building. Night flushing reduces the indoor air temperatures at the beginning of the next day and the cooling demand over the day.

The outdoor climate is changing and the airtightness and insulation levels of residential buildings are improving. During the warmer season this can lead to overheating problems, especially when the house is situated in urban areas. In order to reduce overheating problems, ventilative cooling can be used to keep the indoor conditions at a comfortable level. Natural ventilation is not always a feasible solution, for the risk of burglary, and when the outdoor temperatures are not suitable for cooling the house, for instance in urban heat islands. 

Many studies have shown that the use of mixed-mode cooling can bring down the cooling load significantly while maintaining satisfactory in door air quality and thermal comfort. But there is little information available concerning mixed-mode cooling in China. Thus, basing on design parameters of design standard, A series of computer simulation of a typical mixed-cooling apartment in Guilin, lies south-west of China, was conducted by Eneryplus and Climate Consultant software.

For several years indoor comfort is measured in halls of hospitals by architecture students from the Delft University of Technology. Questionnaires and interviews have shows that patients and visitors have very few complaints about the indoor comfort in hospital halls.  

Adaptive thermal comfort model has been widely used to evaluate the thermal comfort level of natural ventilation buildings.However, current adaptive standards offer a simple linear relationship between the outdoor temperature and the indoor comfort temperature，ignoring the influence of solar radiation.

Ventilation is critical in interpreting indoor air quality (IAQ), yet few IAQ assessments report ventilation rates; even when they do, the measurement method is often not fully described. Most ventilation assessments use a tracer gas test (TGT) to measure total air change rate. In a TGT, the indoor air is marked with an easily identifiable gas (tracer) so that the air change rate can be inferred by monitoring the tracer’s injection rate and concentration.

Measuring ventilation rates in occupied dwellings is challenging but represents the conditions that occupants experience. This paper explores the constraints of existing methods when measuring the ventilation rate of occupied buildings and proposes a new method addressing some of them.