One hundred subjects were exposed to air velocities fluctuating in the same manner as in typically ventilated spaces in practice. Each subject participated in three experiments at 20, 23 and 26 degrees C, dressed toobtain a neutral thermal sensation. In each experiment the subject was exposed to six mean velocities from 0.05 to 0.40 m/s. He was asked whether and wherehe could feel air movement and whether it felt uncomfortable. A relation was established between the percentage of people feeling draught and the mean velocity. The subjects were most sensitive to draught on the head region.
In the weatherization of building structures to minimize convective heat loss, the air exchange rate is reduced. Pollutants of indoor origin are retained near the occupants. Further, outdoor pollutants may be concentrated indoors under partic
Decreased ventilation, achieved by weather stripping and other tightening measures, is the most cost effective way to energy conservation. A very low investment can result in a considerable decrease in ventilation rate. For a typical detached
The simple steady state model which is frequently used to relate radon concentration (C), source strength (S) and ventilation rate (l/tau) is expressed in the equation C=S tau. The assumptions of this model are given and their validity explor
To propose guidelines for minimum ventilation rates which are sufficiently large to meet the demand for fresh air without unnecessarily wasting energy, in IX "Minimum ventilation rates" within the IEA Programme "Energy conservation in buildings and community systems" nine countries are co-operating. The participants have in a first step summarised existing knowledge, national standards and current and required research. The work that was required covers a wide range of disciplines, from hygiene and medicine on one hand to engineering and building science on the other.
40 female and 39 male judges have each evaluated the intensity and acceptance of body odour 29 times on entering an experimental auditorium occupied by 105 women. During the experiment, which lasted three hours and 50 minutes, the ventilation rate was varied while the air temperature was kept constant around 20-21 deg C. Carbon dioxide was measured continuously. No substantial difference was found in the ventilation rates required in spaces occupied by women and men. A ventilation rate around 8 l/s per person is required to satisfy 80% of people entering a space.
This paper describes the results of a study of the indoor climate at 11 Danish schools. The investigation shows how the pupils themselves experience the indoor climate and indicates, for example, the relationship between the volume of outdoor air supplied per pupil and the pupils' evaluation of the quality of the air in the classroom.
A major research endeavour has been initiated to establish the extent to which prevailing ventilation codes for American hospitals should be revised to achieve the dual purpose of improving the patient care environment and increasing the energy efficiency of health care institutions. Accomplishments during the first year of this study and the activities planned for continuing investigations are the subject of this presentation.
In addition to air quality problems encountered in other sealed buildings, both workers and patients in hospitals may be exposed to very special air contaminant problems. Levels and ranges of a variety of chemical pollutants measured in 16 h
ASHRAE's first ventilation standard, published in 1973, has been used in many building codes in the USA. The 1981 revision of this standard has been criticised for its approach to indoor air quality. A comparison of the '73 and '81 standard, currently underway, is expected to better explain the rationale and provide new support for controversial parts of the standard.
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