English

In this study, the houses located in the northern region of Japan had been investigated. The investigation included the measurement of the ventilation rate using four different methods, namely the constant concentration method, measurement of airflow at inlet/outlet and two kinds of PFT method. This paper shows the relationship between the measurement results of ventilation rate via these four measurement methods. It is found that the amount of outdoor air introduced is insufficient for many houses and some of the used ventilation systems are not properly operated.

Airborne particle concentrations of 20 nm to 10 µm particles were studied in two similar classrooms in a school. One classroom was ventilated by mixing ventilation with supply air filtration and one by displacement ventilation without supply air filtratio

We present a method capable of measuring the velocity field in a 7.00m x 3.50m plane of a large-scale Rayleigh-Bénard (RB) experiment using an adapted Particle Image Velocimetry (PIV) technique. The structure of the flow in RB convection is well known for

This paper shows a study of a herring meal factory and the methodology used to improve the indoor and outdoor environment

This paper shows the successful application of CFD simulations for analyzing complex room air flow problems in real applications and deriving optimized solutions.

For a specific thermal anemometer with omnidirectional velocity sensor the expanded total uncertainty in measured mean velocity Û(Vmean) and the expanded total uncertainty in measured turbulence intensity Û(Tu) due to different error sources are estimated

We consider the overnight evolution of an initial two-layer thermal stratification (a warmupper layer and a cooler lower layer) in an enclosure ventilated via openings at high and low levels.Results of our laboratory experiments show that an efficient displacement flow is not always established and four distinct ventilation flow regimes are observed depending on the ratio R (= at /ab ) of the upper opening area, at , and lower opening area, ab ( > 0). For a given initial stratification, displacement flow is established only if R is sufficiently small (i.e. at

The authors recently reported the detailed experimental results on that the discharge coefficient of the openings exposed to the wind driven airflow clearly changes depending upon the windangle and consequent conditions. A full-scale building model in a wind tunnel has been used for theexperiment. In this paper, the mechanism of the change is discussed more deeply, and the predictionmethods of the discharge coefficient are tested by the new experimental results for different conditions of opening size and location.

The natural ventilation of a room with a source of uniformly distributed heating at the base andwith vents at multiple heights is investigated both theoretically and experimentally. It is shown that the impact of additional vents can be predicted by determining the height of neutral buoyancy. As a room is heated it heats up to a uniform state and the relative height of neutral buoyancy depends on the ratio of the upper and lower vent areas. When a simple additional intermediate level vent is introduced a unique solution can be used to predict the resulting air flow.

We report on a series of measurements of the temperature at Houghton Hall, Luton,over the Spring and Summer of 2003. The data show that the building tracks the externaltemperature, but that the amplitude of diurnal temperature fluctuations typically lies within 2-6 C,while the external fluctuations may be as large as 15-25 C. This buffering of the internaltemperature is largely due to the thermal mass of the space which introduces a time-lag ofbetween 0.5-3.0 hours in the response time of the interior to the exterior space, over the periodof our survey.