Discusses air quality and the related definitions of ventilation efficiency. Suggests a definition of efficiency for ventilation systems in residential buildings that takes into consideration how ventilation air spreads within a dwelling. Measurements of the efficiency for exhaust, supply and combined systems show that for combined and supply systems the highest efficiency occurs in those parts where the air is supplied.
Many mechanically ventilated buildings are over-ventilated since ventilation rates are based on a fixed number of people (often in excess of the average occupancy) and no allowance is made for infiltration. States that the CO2 concentration in the ventilated space can be related to the ventilation rate per person, and by modulating the fresh air flow to maintain a constant CO2 concentration, a constant ventilation rate per person can be obtained.
Reviews a research project which has the objective of establishing:< 1. Expressions for ventilation efficiency< 2. Methods for measuring ventilation efficiency< 3. Rules for acheiving efficient ventilation.< Derives expressions for ventilati
Gives measurements of the ventilation as well as the temperature efficiency of mechanical supply and exhaust systems (balanced systems). The ventilation efficiency is a measure of the performance of providing air in the occupied zone and is also an indicator of the air quality. The temperature efficiency is a measure of the system's capability of supplying heat in the occupied zone. Monitors ventilation efficiencies by adopting tracer decay techniques and the temperature efficiencies by measuring the stationary temperatures.
Measures the air infiltration in individual rooms of a one-storey airtight house, using a special tracer gas measurement technique. Concludes that the overall ventilation rate was very low for the test house, although it had mechanical ventilation (exhaust fan). States that the best way of getting adequate ventilation is to install a ventilation system with built-in routes where fresh air can enter the building. This should either be balanced ventilation system or an exhaust fan system with special vents to the outside for supplying fresh air.
Discusses difficulties inherent in multiplexity of full-scale trials and the use of EDP simulation in models. Considers the measurement of low air movement velocities using different types of anemometers and field trials in lecture rooms and open-plan offices. Reports on studies into ventilation efficiency and full scale trials. Reviews International Institute of Refrigeration Congress held in Essen September 1981.
Defines term `ventilation efficiency' and notes factors which determine it: air change rate and temperature, sources of heat and pollution and their locations in a room, persons, machinery etc in motion, the design and position of inlet and exhaust air devices. Gives mathematical and illustrative flow models.
Reviews the development of methods and results achieved. The methods have resulted in a proposal for a Nordic test method for measuring ventilation efficiency (local air change frequency) using tracer gas techniques and measurements carried out for two different ventilation systems.
Reports on research project to study the effects of different methods of heating an office, temperature and draught conditions, ventilation efficiency and heat storage in joint structures. Gives test room digramatically and tracer gas concentration under different conditions, both during summer andwinter.
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