Dampness in residential buildings is detrimental to the health of the occupants and causes the growth of mold and decay in the fabric of the building materials. In Taiwan the average winter relative humidity is 80% and the average temperature is 15°C (59°F). It has been found that the average winter indoor moisture content in Taiwanese apartments can be higher than the outdoor content by as much as 15%. Although the main cause for the increased indoor humidity levels has not been identified, removing the moisture generated from shower baths can help reduce the humidity.
A number of approaches exist to evaluate building ventilation and indoor air quality. In some situations, the measurement and analysis of indoor carbon dioxide concentrations can be useful for understanding indoor air quality and ventilation. On the other hand, oversimplified descriptions of measurement procedures based on carbon dioxide have been presented, and there have been many instances in which indoor carbon dioxide concentration measurements have been misinterpreted and misunderstood.
This paper reports the findings of a pilot field study carried out to investigate the internal and external pollution levels in two buildings, one naturally-ventilated and the other air-conditioned and to investigate their relative attenuation of external pollution levels. The study is a precursor to more extensive studies aimed at providing guidelines for the design of energy-efficient buildings with a good indoor environment in urban areas.
The provision of ventilation air for high-rise multifamily housing has plagued retrofit practitioners and researchers alike. How does one determine whether sufficient levels of outdoor air are being provided to all apartments in a building? And how does one know whether the systems can be retrofit to improve their energy efficiency without compromising air quality?
Increased building indoor air quality (IAQ) complaints due to reduced outdoor air ventilation rates led to ASHRAE Standard 62-1989. Even though the stipulated total outdoor ventilation flow rate may be drawn into the HV AC system, thermal imbalances in the various zones of the building can lead to certain zones being starved of the specified ventilation flow rate thereby creating localized IAQ problems.
Poor indoor air quality caused by poor ventilation was indicated from field measurements in apartments in Taiwan. Four strategies of employing thermal buoyancy effect, dedicated air flow pattern, transom and spatial connection control are proposed to improve indoor air quality by removing indoor pollutants with outdoor air. To prove the concepts, a bathroom design based on the proposed strategies is presented by numerical simulation using 11 computational fluid dynamics code.
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