oxygen

To evaluate effect of indoor environment quality on productivity, the changes in cerebral bloodoxygenation by near infrared spectroscopy was examined. In this study, relationship between the changes in cerebral blood oxygenation and difficulty level of task was evaluated by subjective experiments. Four tasks were given to the subjects: single-digit addition, double-digit multiplication, triple-digit addition, and triple-digit multiplication. It was evaluated that the more difficult task types to solve, the more oxygenated hemoglobin and total hemoglobin concentration were needed.

Describes how workers at altitude are subject to hypoxia, which impairs the ability to sleep, mental performance, productivity and general well, being. Discusses the effectiveness of injecting oxygen into the air conditioning systems for these workers, which has the effect of reducing the equivalent altitude. Several studies have been made to test oxygen enrichment and have shown improvements in sleep quality and cognitive function. The fire hazard is less than in air at sea level.

Reports the result of investigation of the impact of various operational factors on trace combustion products emission rates from unvented gas appliances including ranges and space heaters. The impact of the following factors on the indoor NO, NO2 and CO emission rates were evaluated under controlled conditions in an environmental chamber - 1) the appliance typeand/or design, 2) the primary aeration level, 3) the fuel input rate, 4) the time dependence of emission rates, and 5) the presence of absorbing surfaces such as wood, plaster board, curtains, carpets, linoleum and plaster.

Reports the results of three programmes of measurements of ventilation carried out in one-family houses, which in most cases were of the 'council house' type. The first programme measured ventilation rates using tracer gasin two houses room by room. Wind speed and direction were recorded but no general relation between ventilation and wind was found. The second measured ventilation rate in individual rooms in a house under six different wind conditions. The third measured ventilation rates in three identical homes.

Describes measurements made to compare ventilation rates in six Belgian houses with both natural and mechanical ventilation systems using O2 and N2O as tracer gases. Ventilation rates were correlated with wind speed. Air leakage across individual components of the house was measured and from this the distribution of leakage areas calculated.

Describes the determination of infiltration rates for houses in Seneffe. Gives infiltration rates for individual rooms, found using O2 as tracer gas, and recording wind speed and direction. Determines global air renewal rate using N2O as tracer gas, by injecting gas through ventilators into all rooms and measuring concentration in each room. Calculates global concentration from individual measurements.

Using nitrous oxide as a tracer, the author made 390 measurements of ventilation rates in seven closed rooms of six houses, in Melbourne, Australia. Half of the observations were taken when the wall ventilators were sealed, in order to explore their influence on room ventilation. Results for each room, grouped in ranges of wind direction and according to whether ventilators were open or closed, are shown as regression curveson plots of ventilation rate against wind speed. The ventilators are shown to have only a slight effect on ventilation.