The reduction of ventilation in buildings as an energy saving measure may result in a deterioration in indoor air quality. Suggests use of contaminant control devices and summarises devices available. These are filters, electrostatic precipitators, mechanical dust collectors, scrubbers, and contaminant combustors Suggests five areas where further research is necessary.
States condensation caused by high humidity is a major problem in British homes. Describes a conventional heat pump dehumidifier for removing moisture from the air. Describes the advanced dehumidifier developed by the Electricity Council Research Centre which is designed to work in cold damp conditions typical of British winters. Gives details of the design and reports that tests of a prototype show that the design is more than twice as effective in terms of litres of water extracted per unit energy than conventional designs.
Energy lost through ventilation becomes increasingly important as building insulation levels improve. Describes application to this problem of heat pump dehumidifier which transduces latent heat of moisture in cool damp air into sensible heat of warm drier air. Describes laboratory prototypes which combine sensible heat from counter flow heat exchangers with heat transfer properties of a heat pump. Claims such systems perform twice as effectively as conventional equipment and offer a new approach to ventilation losses.
Reports tests of the effect of various air treatment devices on the radon daughter concentrations within a room. Test were carried out using an electrostatic precipitator, a humidifier and a dehumidifier. The ventilation rate of the room was measured using Krypton 85 as a tracer gas.< Finds that the use of a humidifier, dehumidifier or carbon filter gave no significant alteration to the radon concentrations in the room, but that the electrostatic precipitator reduced the concentration considerably and was equally effective when operated with or without the carbon filter.
This is a short guide to mastics and sealants used to seal the joint between an aluminium window and a structure. Gives table of materials available, and their properties. Gives detailed instructions for applying sealants to window joints.
Indoor air quality in an air conditioned California high school has been measured over a variety of ventilation rates ranging from 13.3 cubic feet of outside air per minute for each classroom occupant to approximately 1.5 cfm per occupant.< Parameters measured include outside air supply rate, the occupants' subjective perception of indoor air quality, airborne microbes, carbon dioxide, carbon monoxide, nitrogen oxide, sulphur dioxide and ozone in two classrooms, a halland outdoors.
Discusses energy saving measures taken in the Ekono office building, headquarter of Ekono consulting engineers, situated near Helsinki. Describes the use of hollow slabs for intermediate floors, tight window construction, the extract air window system, efficient lighting and computer control of ventilation. It is planned to control ventilation by monitoring the concentration of carbon dioxide in the building. Reports measurements of infiltration rate with nitrous oxide as a tracer gas using both constant concentration and decay rate techniques.
The conduction of sound through the gap between window and wall depends on the width of the gap. This width also determines the air leakage, suggesting that air leakage might be measured by an acoustic method. Notes method requires that cracks are relatively large and have fewer than three kinks. Reports measurements in a wind tunnel of air flow through crack models made from aluminium and compares results with theory. Finds empirical expression relating pressure difference to air flow and gives graphs of results.
Describes method for calculating the adventitious ventilation of a building using information from a pressurization test. The method requires a knowledge of the surface pressures on a building, calculated from wind speed and direction, the inside-outside temperature difference, and the distribution and characteristics of openings in the building shell. Applies formulae to threebuildings and finds a great dependence of infiltration on wind direction. Discusses the effect of wind and stack effect, separately and combined.
An automated air infiltration measurement system for large buildings isdescribed. The system consists of a micro-computer, electron capture gaschromatograph, a ten port sampling manifold, and five tracer gas injectionunits. The system controls the injection and sampling of tracer gas in amulti-zone building, calculates the air infiltration rates of each zone, andmeasures the on-time of events such as HVAC fan operation, exhaust fan operation,and door/window openings.
Login