English

A sudden contamination of the outdoor air by some toxic gas can have several causes. The primary goal of the investigation was to determine the protection afforded by sheltering indoors. The object of a computational approach was a single family house with two floors. Three different models were utilized as computing tools: MOVECOMP to calculate the infiltration air flows, MULTIC to calculate the contaminant transport inside the building and TDYN to calculate the temperature decay of the building.

A humidity controlled exhaust fan have been tested during the winter season 1991/2. The test have been carried out in a detached one storey house with a flat roof. The relative humidity (RH) have been measured in the following modes: * natural ventilation only* wall mounted fan, setpoint 70% RH, and natural ventilation * fan in the exhaust duct, setpoint 70% RH.The relative humidity levels have been monitored in the shower room and in the other part of the dwelling. The temperatures have been measured in the exhaust duct and in four places in the dwelling.

Due to the complexity in describing the simultaneous effects of a number of factors that influence the climate of an attic space it has proven to be difficult to make simulations of it. This report deals with the problem of using different computer programs for ventilation, heat andmoisture balance in an integrated way so that a proper description of the expected attic climate can be achieved. A general overview of attic space climate and the factors affecting it will be given and it will be described how the simulation packet works.

Besides the hygienic aspect, also the aspect of energy saving of heating residential buildings is very important. This is only possible by mechanical ventilation with heat recovery. This paper describes a part of the large variety of systems, which are nowadays available on themarket. The main difference of these systems are: * single room unit/decentral unit and * central unit for one dwelling or a single family building.

The ventilation rate in a building depends on many things, one of which is the air temperature. The air temperature in turn depends in part on the ventilation rate. The effects of this relationship are generally overlooked in both thermal and ventilation models. To study this effect a model has been developed which integrates the models GAINE and SILONA developed at CSTB. This allows the prediction of the natural ventilation rates caused by the actual temperatures in the building.

The study deals with the theoretical and experimental simulation of gas leaks in buildings. Such simulations may provide helpful information about the flow characteristics and dangerous concentrations as a function of the ventilation system (if any), the geometrical features and the thermal constraints on the room, and eventually about the positioning of gas monitoring devices.

This paper investigates quantitatively the energy conservation achieved by balanced ventilation with heat recovery and upstream ground heat exchanger. The investigations were conducted on an occupied single-family house equipped with such a balanced ventilation system. The heat recovery unit of this system consists of a plate-type heatexchanger with a downstream small air-to-air heat pump. In addition this house is equipped with a ground heat exchanger.

A heat recovery system reclaims heat from outgoing stale air, supplying it to incoming fresh air. The energy benefit is greatest if it supplies all the fresh air to the house and none enters via uncontrolled openings, hence ventilation heat recovery (VWR). A sunspace (or conservatory) attached to a dwelling will almost always be at some temperature above ambient. Heat losses by conduction through the adjacent building fabric and ventilation losses via cracks will be reduced.

The house dust mite inhabits bedding and soft furnishings in homes. It is implicated as a major cause of allergic asthma. Maintenance of indoor humidity below a level of 7 g/kg inhibits the growth of the mite population. A pilot survey was carried out by EA Technology in cooperation with the Building Research Establishment to investigate the effect of mechanical ventilation with heat recovery (MVHR) both on indoor humidity and mite abundances.

The amounts, quality and factors affecting of dust accumulation in supply air ducts of eight nonindustrial buildings were studied. The average of surface density of dust settled in supply air ducts was 10.6 g/m² and the average of yearly accumulation rate was 3.5 g/m²*year. The dust contained 82% of inorganic material, which agrees well with the composition of outdoor air dust in down town areas. In straight air duct the surface density of settled dust decreased as a function of distance from the air handling unit (AHU).