odour

Reviews the most important sources of indoor air pollutants, and means of measuring the contamination of room air by persons (carbon dioxide and odours). Lists some recommendations for minimum ventilation rates, based on the results of experimental investigations.

Discusses reasons behind occupant ventilating behaviour, such as: 1. general attitudes, particularly regarding energy, 2. occupant requirements, 3. components of the habitat micro-climate, 4. optimum micro-climate and desired micro-climate, 5. means available in the habitat to modify the micro-climate - a. general means, b. ventilation as a specific means, 6. balancing requirements against means, 7.

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.

Notes that the information in the ASHRAE 'Fundamentals' volume on how much ventilation ought to be provided is based on work nearly 50 years old. Reports new work on permissible ventilation rates produced by H B Bouwman of the Dutch Research Institute for Environmental Hygiene of the Central Organisation for Applied Scientific Research TNO. The numerical purpose of the work was to find the rate of ventilation required to keep complaints from occupants of rooms about unacceptable smells to less than 5% or 1%.

A discussion of different approaches to indoor air pollutant monitoring is presented. Indoor sampler design criteria are outlined. Grab samplers, personal samplers, passive and single-use devices, and in-situ measurement instruments are compared to novel, syringe/adsorbent tube samplers. These instruments provide automated, sequential, time-averaged collection of avariety of indoor pollutants, including hydrocarbon/halocarbon organic vapours, CO, CO2, HCOH, tobacco smoke, combustion and odorous mixtures, and particulate matter. In addition, the samplers can be used in infiltration studies.

Eleven countries are cooperating to establish guidelines for minimum ventilation rates which are sufficiently large to meet the demand for outdoor air in buildings without unnecessarily wasting energy. The most important pollutants have been identified as: carbon dioxide, tobacco smoke, formaldehyde, radon, moisture, body odour, organic vapours and gases, combustion products and particulates. To a certain degree some of thesesubstances can be used as indicators for acceptable air quality to establish minimum ventilation rates.

An investigation of the minimum fresh air supply per person required to prevent the occurrence of unacceptably offensive odour due to stale air in offices and similar buildings. The study was made under everyday conditions as far as possible, in different buildings, various size rooms, different densities of occupancy, with men or men and women, and with mechanical or natural ventilation.

Sedentary subjects occupied an environmental chamber (20-22 deg C, 35-50% RH) with low ventilation for 90 min. Judges (visitors) evaluated the odour of the chamber before and during, and after the 90-min period of occupancy. Odour intensity increased throughout occupancy and decayed afterwards. However, therate of decay exceeded that anticipated from ventilation rate alone. The results implied that body odour is unstable with a half-life of 55 min. This instability will influence quantitative requirements for ventilation during nonsmoking occupancy.

The amount of outdoor air supply required in rooms were no one was smoking and only body odour was pesented was investigated using a climate chamer, under clean room conditions. Ten subjects were confined in the room and five panels outside of the room stated the odour level in the sampled air from theroom when compared to clean air. Experiments were performed in four steps of 5,10, 20 and 30 CMH per person. Room temperature was either 22-23 deg C or 32-33 deg C with a relative humidity of 50-60%. The higher temperature was used to study the influence of body odour in sweat.

A livestock building for 30 cows in loose housing was constructed in 1982. In the cow stable natural ventilation is provided through openings along the eaves. New types of inlets and outllets have been designed for natural ventilation systems. The regulation system for the air flow rate is a modified P-type regulator. Using timesharing of the regulation function, the inlet areas can be regulated in groups by means of four different temperature sensors in the building.