Discusses the Swedish trend to build super insulated nearly airtight dwellings. Mentions problems encountered in tight buildings, such as severe ground floor condensation and mould growth. Shows the importance of the vapour barrier in preventing condensation. Compares exhaust and balanced ventilation systems in tight houses. States that sealing houses in Sweden is costeffective, partly because of an integrated approach to incorporating energy saving features in new housing.
Describes a recent survey of a large ink manufacturing works in an effort to solve thermal comfort problems by improving the ventilation of specific areas of the plant. Six buildings were investigated. Illustrates them diagrammatically and explains the ventilation solutions recommended. Explains the base of the estimated construction and installation costs.
A major pathway for loss of conditioned air in east Tennessee homes with externally located HVAC systems is leakage in the ductwork. The effect on infiltration rates, as measured by Freon-12 tracer gas dilution, becomes marked if the central duct fan is operating. Duct fan on and duct fan off measurements of the rate of air exchange gave mean values of 0.41 and 0.78 ach respectively in a total of 31 homes.
Reports on symposium in Belgrade, 1978, on the consequences of blocked and contaminated ventilation ducts. Notes current research by Swedish Building Research Council into hospital ventilation systems and other work on aspects of contamination and its effect on efficiency. Also reports on investigations into ventilation in housing. Diagrams illustrate various parameters and the effect of cleaning and contamination on airflow and efficiency. Considers economic periodicity of cleaning. Stresses importance of cleaning heat exchangers. Article concludes with a subject bibliography.
Conducts tests over a period of 18 months in a house near Knoxville Tennessee to determine the effect of forced ventilation on the infiltration rate. Uses an outside-vented electric dryer as the power vent. Carries out testing during a variety of weather conditions. Uses SF6 as a tracer gas to measure infiltration rates. Develops a non-linear regression based on measured data relating the change in house infiltration rate to the vent rate.
When wind and mechanical ventilation effects work together simultaneously, the combined effects of the two cannot be given by simple linear summation. Investigates this non-linearity of pressure differentials by the wind tunnel test of a model building, and verifies its effect on air infiltration.
Due to energy shortage and increased energy costs, there seems to be conflicting interest between hygiene and comfort on one hand, and energy economy on the other. Fortunately, it is possible to increase the ventilating air change rate in the zone of occupancy without increasing the air change rate for the whole room in question. Describes different methods for measuring and defining ventilation efficiency, and tests some of these methods in the laboratory, along with different ventilation systems.
A large number of air-conditioned office blocks constructed in recent years in the FRG have been equipped with waste-air ventilated windows. Based on experience now available from planning, laboratory tests and practical operation, describes the different design principles and their technical characteristics. Bases the evaluation on window designs which have been used in 11 office buildings totalling 10000sq.m useful floor area.
Despite having balanced mechanical ventilation, a large number of modern buildings in Sweden have unsatisfactory indoor climate. Problems include mould, irritation of the eyes, nose and throat, skin rashes, feelings of dryness, hoarseness andheadaches. To control ventilation according to requirements the right indicator variable must be selected and the system must permit the proper control in the occupied zones. Measurements of air pollutants were carried out outside and inside a mechanically ventilated office building.
Parts 2 and 3 of a series of articles. Describes office buildings with natural and mechanical ventilation systems mentioned in part one, where the mechanical ventilation plus humidification and cooling is used only during the coldest parts of the winter and hottest parts of the summer. Provides comparative cost analysis for the building. Discusses design criteria to take account of fullor part time natural ventilation. Treats maximum room depths, window types,external and internal doors, furniture, room layouts.
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