air quality

Describes a system installed in the EKONO office building in Helsinki which allows the amount of CO2 in the exhaust air to control the ventilation rate. Uses a CO2 indicator, and adjusts the mixture of exterior and recirculated air so that the amount of CO2 during working hours is kept on ca 700 ppm. Describes use of equipment during winter 1981-82, when exterior air flow is registered. Measures the proportion of CO2 locally in order to study occasional variations that may occur. Studies the proportion of other pollutants in the room air with a gas chromatograph.

Reports a survey on both solar and conventional homes in north-eastern New York State. Finds that houses which are more airtight have 3 times the radon levels of conventional houses. The highest 2 levels of radon in the solar homes give doses over 30 yrs that are known to produce lung cancer in 1% of uranium miners. Summer readings in more than one half of the cases are different from winter ones by a factor of 2 or more, so that year-round measurements are necessary for precise dosimetry. The track etching technique is ideally suited for such measurements.

Explores the health implications, external and internal contributions, and the measurement of indoor air pollution including such subjects as sampling and analysis, calibration, time scale and interferences. Outlines the current status of prediction techniques, including areas such as one-compartment models, infiltration estimation, and empirical models. Summarizes the most common control methods. Examines, in detail, the application of modelling techniques to several typical indoor settings, for example, a restaurant, kitchen or a conference room with smokers.

Identifies alternative methods available to control indoor air pollutant exposures. Describes the performance characteristics of ventilation systems and of air cleaning devices used in mixed modes for ventilation of occupied spaces. Reviews models for predicting effectiveness of several alternative modes, with field trial validation results cited where available. Briefly reviews previous confined-space studies as points of departure for consideration of necessary air quality, ventilation and air cleaning.

Describes a test carried out in the Fridley, MN, Junior High School Music Dept. to obtain air quality, energy and subjective response data on an Automatic Variable Ventilation System. Devises a control system with both CO2 and temperature inputs to control the use of outdoor air. Infiltration measurements lead to a quantitative measure of ventilation efficiency, which in turn lead to recommendations for air circulation patterns in rooms. The measured ventilation efficiency enables energy and CO2 models to fit measured data. Finds energy savings of approx. 20% in this application.

Shows the usefulness of a model for extrapolating environmental chamber results on pollutant emissions from combustion appliances to determine indoor pollutant concentrations in actual residences. Investigates the effects of infiltration, whole-house ventilation, and spot ventilation on pollutant levels. Results show that a range hood is the most effective means of removing pollutants emitted from a gas-fired range; removal rates vary from 60%-87%.

Carries out measurements of indoor atmospheric environment in a day nursery and a kindergarten in Denmark, where natural air infiltration supplies the room with only 1-2 m3 fresh air per person and hour under the prescribed occupancy. Duplicates situation under controlled conditions in a climate chamber. Results indicate unacceptably high concentrations of carbon-dioxide, and show the need for more elaborate building design in airtight buildings.

Treats the relation between transmission heat loss and ventilation heat loss of buildings. Notes normal methods of fresh air ventilation of dwellings and problems arising with buildings being made increasingly airtight so that air infiltration is greatly reduced with consequent condensation and lack of maintenance of minimum hygiene standards. Illustrates and discusses possible future ventilation systems including mechanical supply and extract ventilation systems incorporating heat recovery systems. Illustrates several alternatives diagramatically.

Gives a series of short articles on air quality, air infiltration, and the ventilation needs of low energy buildings. These are -< 1. Sandberg M. Quantifying the pollution. Defines the quality of ventilation< 2. Warren P. Predicting infiltration rates. Explains BRE's method of predicting air infiltration in houses< 3. Getting close to zero. Describes the low energy EKONO office complex< 4. Sherman M. Grimsrud D. Which ventilation system? Shows that the choice of the economically optimum ventilation system depends on the tightness of the building.