carbon dioxide

Describes methods used at ECRC for measuring the ventilation rate in houses. Two tracer gas methods are used, the decay method and the constant concentration method. Measurements have been made using both nitrous oxide and carbon dioxide as tracer gases. Also describes test of air leakage made by pressurizing the entire house. Gives for each method a detailed description of the measurement technique.

The Lawrence Berkeley Laboratory measured the indoor air quality at Fairmoor Elementary School in Columbus, Ohio. A mobile laboratory was used to monitor air outdoors and at three indoor sites (two classrooms and a large multipurpose room); tests were made at three different ventilation rates. The parameters measured were outside air flow rates, odor perception, microbial burden, particulate mass, total aldehydes, carbon dioxide, carbon monoxide, sulfur dioxide, ozone, and nitrogen oxides.

Reports study of the energy consumption and ventilation requirements of typical existing public schools in New York. Electricity and fuel-oil consumption data from May 1970 to April 1973 from 19 schools were analysed.

Reports measurements of air leakage rates in the four energy-conservation research houses using the fan pressurization method. One of the houses is standard for the area and the other three houses have added insulation and vapour barriers. One house has a heat pump and one an air-to-air solar heating system. Air infiltration rates were measured in two of the houses using CO2 as a tracer gas. Discusses results and compares tracer gas with pressurization tests.

Reports findings of investigations carried out by West German Federal Ministry of Health in July 1978 into the internal climate in the one third of the rooms in a representative West Berlin school which are located in the building core. These rooms have mechanical ventilation and artificial lighting. Gives results of measurements of room temperatures, air change rates, (measured using N2O as a tracer gas), concentration of carbon dioxide and acoustic performance of the rooms.

Discusses acceptable levels of CO2 contamination in occupied rooms. Describes measurements in a classroom over 3 days using an infra-red analyser with natural ventilation via the windows. Illustrates curves for CO2 concentrations in 8 graphs for closed windows. Notes that limiting value of 0.1% by volume CO2 (1000ppm) is reached in from 5 to 15 minutes. Repeated sudden ventilation by opening windows is not practicable. Evaluates air change rate. Concludes energy saving for ventilation in heavily populated rooms is only attainable by mechanical ventilation with heat recovery.

Reports investigation of the air quality in a sound-insulated dwelling house. Measurements of ventilation rate and concentrations of CO, CO2, and NO2 were measured in a tight sound-insulated dining-kitchen, with and without the operation of a gas range, instantaneous hot-water heater and ventilation fan. Finds that natural ventilation was inadequate when the gas appliances were operating and recommends that an instantaneous gas hot-water heater should be provided with an exclusive air exhauster.

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.

Reports methods used to measure the concentrations of Rn, Tn, and their decay products indoors and outdoors. Radon and Thoron concentrations are detected continuously by collecting the positively charged RaA and ThA atoms on a surface-barrier detector using electric field precipitation.< The concentrations of Radon and Thoron decay products were determined by collecting them on a membrane filter and simultaneously counting the activities by means of a collimated surface-barrier detector.Indoor and outdoor concentrations are measured simultaneously under different ventilation rates.