A simple study is described which demonstrates the relative importance of the various parameters which determine ventilation, using basically the single-cell version of the British Gas multi-cell model. The graphs presented can be used directly to estimate natural and mechanical ventilation rates under a wide variety of simple conditions. By adopting a non-dimensional approach which introduces the concept of the whole house leakage Reynolds number, the basis is laid for a more general means of estimating ventilation from graphical data sheets.
Using meteorological and physical data, a model simulating pressure and air mass flow distribution in buildings was produced using the method of non-linear networks. It was used to study wind and buoyancy effects on mechanically ventilated buildings. Calculations were made for a naturally ventilated high rise building for varying permeability distributions and air flow resistances of the building envelope, using data from real buildings and from previous cases described in the literature.
Describes measurements made in a real factory building and comparisons with the scale model tests presented in the previous report. The ventilation system of the factory building is a mechanical one with the necessary rate of ventilation designed to be less than that calculated by the conventional method. The parameters studied included air velocities measured with hotwire anemometers at the inlet openings and the temperatures in the work hall itself measured from a crane.
Describes the pollutant burdens on indoor air. Notes heat exchanges by air renewal and associated heat losses. Examines how to determine the required air change rate. Lists the minimum air changes for various types of building with and without smoking. Treats air infiltration. Considers how to reduce losses with air renewal by weather stripping, special air inlets, reduction of the indoor air temperature, heat recovery with controlled mechanical ventilation, heat pumps and heat pipes.
The quantity of air in several rooms lying in a stack connected by means of fresh air and exhaust air ducts is considered as a simple model of amultistorey building. Negative pressures set up within the rooms can be equalised by adjusting the
Results of air quality measurements are presented for a group of low-leakage houses located in Saskatoon, Saskatchewan. A total of 46 houses were tested for formaldehyde, nitrogen dioxide, radon, and humidity levels. The median level of formalde
Examines the causes of condensation problems and ways of reducing or eliminating them. Deals with diffusion through the building envelope, mechanical dehumidification and ventilation. Considers condensation inside cavities and roof spaces.
Presents methods for the measurement of air flow rates, including methods for measuring flow in ducts, at exhaust and supply air devices and for air change rates for using tracer gas.
Reports on pressure tests carried out on the Kasarminkatu 24 building (a museum of architecture) in Helsinki. The fans in the building were used to measure airtightness of the building envelope, and the tightness of windows and doors was measured separately by the guarded box method. The tightness of the building envelope was good (2 ach at 50 Pa). 70% of total air leakage came through the wooden roof structure, and only 5-10% through the windowstructure. Three alternative mechanical ventilation systems were also studied in the same building to assess their impact on indoor climate.
Notes the trend to installing windowless kitchens, bathrooms and W.C.s in the internal zones of dwellings. Describes a research project to measure for internal kitchens the energy consumption and emission of equipment, the total daily energy consumption, air temperatures, air humidity values during cooking, comfort and air speed. Illustrates the test kitchen and gives the results of measurements of around 100 days of simulated operation for a household of four. Notes the consequences for recommended normal and peak ventilation rates.
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