Indicates that 35-70% of a building's annual energy consumption is used by ventilation plant. Notes difficulty in determining which energy saving measures are most profitable but states that restricting fresh air supply tothat required is one measure that has not been considered and that most systems are designed for maximum capacity without facilities for varying load according to conditions. Describes plant which uses CO2-controlled ventilation in a sports hall. Illustrates circadian changes.
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.
Examines by means of analytically calculable borderline cases the relative merits of continuous window ventilation or intermittent opening of windows. Illustrates the results relating to carbon dioxide content of the rooms ingraphs and discusses them. Findings depend strongly on the hygiene assumptions by which they are judged (identical maximum or identical mean CO2 concentrations or the identical mean air flow rate).
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.
Studies a modern energy efficient office building in a series of experiments with mobile laboratories connected on-line with the building. Measures inorganic air contaminants (CO, CO2, NO2). Makes off-line measurements of volatile organic con
Lists in a table and discusses the chief sources of indoor air pollution. Distinguishes between short term and long term pollution. Provides advice for reducing pollution from various sources. Discusses the minimum permissible fresh air supply rates. Gives recommended humidity values and when, how often and for how long should ventilation be carried out. Recommends 12-15 m3 fresh air per person per hour, with double this rate for physical activity or smoking. States fresh air supply should be monitored to ensure the carbon-dioxide content does not exceed 0.15%.
Assesses the indoor air quality at Oakland Gardens Elementary School in New York City under 3 different ventilation rates. Uses a mobile laboratory to monitor air quality in 2 classrooms, a hallway and outdoors. Parameters measured include air exchange rates, particulates, odour perception, carbon dioxide, carbon monoxide, sulphur dioxide, ozone, nitrogen oxides, radon, formaldehyde and total aldehydes. When the ventilation rate is reduced, carbon dioxide concentrations increase significantly, but do not exceed current occupational standards.
The heating system of a Junior High School in Minnesota has been re-equipped with a CO2-controlled variable ventilation system. The outdoor air dampers remain fully closed whenever the CO2 concentration is below a specified setpoint. During the early months of 1980, the system operated in alternate periods under the conventilanal temperature-driven control strategy and the experimental CO2-driven control strategy.
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