measurements

If inhaled, welding fumes can be harmful to health, thus exposure must be controlled. A commonly used method of control is local exhaust ventilation (LEV) in the form of moveable capturing hoods but, to achieve efficient capture, this type of ventilation must be positioned close to the fume source and moved as welding progresses, although in practice re-location may not always occur. Alternatively, control may be exercised using a low volume high velocity system (LVHV), fitted either to an existing welding torch or manufactured as an integral part of a torch.

Windcatchers are roof mounted devices that use the action of the wind to provide top down natural ventilation to a room. Here, fresh air is channelled into a room while, at the same time, stale air is drawn out. This provides a simple but attractive natural ventilation methodology that is increasing in popularity in U.K. schools. However, an analysis of system performance has largely been limited to laboratory based measurements and the use of CFD to generate predictions.

Radon surveys started in Estonia in 1989. The Department Building Physics at the Estonian BuildingResearch Institute measured radon levels in dwellings, in building materials produced in the country,and in the soil. The indoor radon concentrations in more than 400 houses were measured under grabsamplingtechniques using Lucas cells. The highest measured radon level was 6700 Bqm-3. The resultsof these measurements made during 1989-91 showed that the main source of indoor radon is the soilunderneath buildings.

This study has explored the possibility and potential of using a thermal active mass system for reducingthe temperature rise and increasing the thermal comfort in an office room. The Controlled Active Mass(CAM) will be used as a heat sink to absorb heat from the room in order to increase the thermal comfort.Physically, the CAM system was designed as a cubic-shaped tank filled with water, with the tanksurfaces either polished or black.

Natural ventilation is a commonly used principle when ventilation systems for buildings are designed.The ventilation can either be obtained by automatically controlled openings in the building envelope, orit can just be the simple action of opening a door or a window to let the fresh air in.

Air conditioning in offices has become current practice in North Western Europe. Main reasons are thehigh internal loads and solar gains. That move away from the heated, naturally ventilated cellularoffice increased comfort complaints.Two cases are presented, confronting enquiry results with measurements. In both, the enquiries gavea number of dissatisfied at the noted mean vote much higher than the standard PMV/PPD curvesuggests. Measurements in turn showed that only in one of the two case complaints could beexpected.

Indoor humidity is an important parameter influencing the occupants’ perception of indoor air quality, and is also a cause of harmful processes that may occur on surfaces of materials, such as cracking of walls or microbiological growth. Building material

This paper deals with the relevance of Computational Fluids Dynamics (CFD) results confronted to measurements carried out in real environment. Experimental tests have been undertaken in a room and in a kitchen of an experimental house. Although the wall surface temperatures and the air intake temperature have not been imposed, the air change rates have been controlled during the measurements. Moreover, since measurements have been
carried out in a real environment, air leakage has occurred at the walls.

Solar shading devices can significantly improve thermal comfort and reduce cooling loads and potential glare problems in highly glazed buildings. This paper describes results from an extensive measurement program that started in 1997, covering external shading devices, products placed between two panes (interpane), and internal shading devices. Measurements of the total solar energy transmittance (g-value) have been performed using a double hot-box arrangement placed in a real climate.

Cavity wall is often proposed in the building envelope design as a solution for improving the thermal comfort of the inhabitants and reducing the adverse condensation effects on the building fabric. In order to evaluate the thermal effect of ventilated air gaps on building energy demand and comfort, an experimental ventilated cavity wall has been built and tested. The cavity wall separates two ambients at different temperatures that are assumed to be constant over the time required to perform the experimental analysis.