AIVC - Air Infiltration and Ventilation Centre

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Indoor air humidification, sick building syndrome symptoms, and perceived indoor air quality in the office environment

Dryness is still one of the major complaints concerning indoor air quality in office buildings and respective nonindustrial environments. Dampness in buildings in terms of excess amounts of water in the solid parts, and the harmful consequences have been discussed vigorously in recent years. Indoor air humidity, which means water vapour in the indoor air, has been given less attention.

Low winter humidity indoors has a negative effect on the performance of office work

Thirty subjects (17 female) were exposed for 5 hours in a climate chamber to clean air at 5%, 15%, 25% and 35% RH at 22 °C, in balanced order. Another 30 subjects (15 female) were similarly exposed to air polluted by carpet and linoleum at 18, 22 and 26 °

Influence of temperature and humidity on the perception of odours Einfluss von temperatur und Feuchte auf die Wahrnehmung von Geruchsstoffen

Experiments were operated to estimate the influence of temperature and humidity on the perception of odours in the air by trained and untrained persons .

Moisture transport across imperfect hydraulic contact interface - A parametric study

Material properties, water vapor permeability, sorption/suction isotherm and moisture diffusivity, are prerequisite for application of all hygrothermal models. Based on the experimental results and well-determined material properties, a numerical model was validated. This model was then used to analyze the sensitivities of the moisture flow across imperfect hydraulic contact interface with respect to these three material properties.

Thermal comfort in low-cost dwellings : a case study in Curitiba, Brazil

The main goal of the present study was to determine thermal comfort parameters for dwellers of low-cost houses for a given set of indoor environmental conditions. 112 people living in over 60 dwellings were interviewed, according to a comfort questionnaire where information regarding age, sex, clothing, level of activity, thermal sensation and preference of the subjects was collected. Environmental factors such as air temperature and humidity were simultaneously registered with T/RH data-loggers. Results were then analyzed by comparing subjective and environmental factors.

Performance evaluation of rotary dessicant wheels using a simplified psychometirc model as design tool

In the present communication, a psychometric model has been presented to evaluate the performance of rotary desiccant wheels based on different kind of desiccants e.g. silica gel and LiCl. The developed psychometric model is based on simple correlations between the relative humidity and enthalpy of supply and regeneration air streams. The model is used to predict the performance of three type of desiccant rotors (Type-I, II and III). The model is tested corresponding to a wide range of measurement data.

The relationship between humidity and indoor air quality in schools

Indoor air quality differences were investigated among five schools with and five schools without active humidity control systems. The active humidity systems provided approximately 15 cfm/person of ventilation air, while the schools without the active humidity control systems averaged less than five cfm/person. The space humidity levels in varying widely without active humidity control, and rose to unacceptable levels during summer shut-down periods.

Displacement ventilation for room air moisture control in hot and humid climate

Few studies dealing with the effect of displacement ventilation on humidity gradient in a hot and humid region have been made . In this paper it is done with a case-study approach (measurements were made in a factory located in the Tropics). The results indicate that the humidity gradient is as significant as the temperature gradient..

Traitement de l'air des piscines couvertes: un imperatif technique et economique pour le confort des consommateurs et la perennite des batiments. Air treatment of covered swimming pools: a technical and economic imperative for user comfort and durability

Discusses how the design of modern swimming pool leisure complexes must adapt to the diverse demands of today's users. States that the air treatment in a covered swimming pool complex depends on a fragile balance between the demands of occupant comfort and the technical imperatives for the conservation of the building structure. It is also of utmost importance to pay particular attention to precisely quantifying the thermal needs, defining the air flow and thermal means of operation, and selecting a principle for dehumidification which is well-tuned to its application.

Formule approchee pour determiner la temperature humide. A formula for the determination of humid temperature.

States that quite simple formulae can be used for humid air, but that this is not the case for humid temperature. Gives an overview of the iterative method to be used in this case.