humidity

People spend 70% -90% of their time indoors. Indoor air quality and human body’s health have a close relationship. With the advance of society, user comfort requirements for thermal environment are rising. Humidity is an important parameter for evaluating indoor air quality, which not only affects the thermal comfort of the human body but also seriously restricts the function of the building. In winter, the indoor humidity is dry. When using humidifier, the humidity around the humidifier is higher, but there is still a dry area in the room.

Since the turn of the century, alarming data produced by the Indoor Air Quality Observatory (OQAI) have led to changes in French legislation, including, most notably, the introduction of compulsory labelling for construction products (decree no. 2011-321 of 23 March 2011).

With 35 years of existence and more than 10 million equipped dwellings, mechanical humidity-based demand-controlled ventilation (RH-DCV) can provide a comprehensive feedback on installation, aging, and maintenance of its components. Their working principle is based on the extensions and retractions of a hygroscopic fabric, which pulls on a shutter to modify the device’s cross-section – hence the airflow – upon humidity changes in their environment. 

In the context of the PREVENT project, preparing a possible revision of the Belgian residential ventilation standard, the way of expressing ventilation requirements, among others in terms of ventilation flow rates, needs to be investigated. The aim of this paper is to propose and compare ways of expression of the ventilation requirements in terms of flow rates with respect to their robustness across dwellings.

Controlling indoor humidity is important in homes, because high indoor humidity is associated with occupant health and building durability issues. Ventilation is often used to avoid peaks of moisture in homes, such as in kitchens and bathrooms. However, in hot-humid climates, outdoor air can have higher humidity than indoors, and continuous whole house ventilation can lead to increases in indoor humidity levels.

This draft paper was developed as a stalking horse for the Windsor 2014 Conference workshop on Statistics, It presents the results of summer time field work undertaken by Abdulrahman Alsheikh in the region of Damman, Saudi Arabia and the data collected shows that middle class homes families there occasionally report thermal neutrality at very high temperatures and humidities.

While people need to know tomorrow’s weather to decide suitable activities and precautions, so do the “intelligent” building management systems. The accuracy of the short-term prediction of the ambient conditions is particularly import for the development  of predictive control strategies.

Interior-surface condensation on the glazed curtain wall of high-rise residential buildings is an important environmental issue in Korea. There are three causes of the surface condensation. One is the curtain wall frame materials, another is the generated moisture from residents' behaviors such as cooking and drying the laundry, the other is inadequate ventilation caused by stack effect.

To clarify the indoor climate in Japanese college classrooms, an air-conditioned, mechanically ventilated classroom of a university was surveyed. Temperatures, humidity and carbon dioxide (CO2) concentration in winter and summer were measured before, during and after lessons. The airtightness of the room and the airflow rate of the ventilation system were also measured. In winter, at an outdoor air temperature around 0 ºC and with the thermostat temperature of the air conditioners set to 30 ºC, the vertical difference in room air temperature exceeded 10 ºC.

A subjective experiment was conducted using 15 college-aged subjects of both genders in order toevaluate their physiological and psychological reactions, performance and fatigue under the differentcombinations of indoor humidity, local air velocity and illuminance.The five-hour exposure periods were divided into three sections of 1.5 hours by 10-minute breaks.During each section, subjects performed 3 times of 20-minute task.