In this study, we monitored the carbon dioxide (CO2) concentration in a high-speed train passengercabin by the in-situ non-dispersive infra-red (NDIR) method in order to investigate the effects of variousfactors, such as number of passengers and the presence of tunnels on the CO2 concentration levels.We found that the CO2 concentration was strongly related with the number of passengers andcorrelated with the presence of tunnel regions. The CO2 concentration increased with increasingnumber of passengers and increasing tunnel residence time.
Field measurements of the indoor climate have been carried out in 128 lightweight timber-framedetached houses in Finland and in Estonia during the years 2002-2005. The temperature and relativehumidity were continuously measured in bedrooms, living rooms and outdoors for each house at 1-hourintervals over a 1-year period.
Conventional techniques for the measurement of adventitious leakage of building envelopes are basedon steady pressurisation at high pressures (e.g. 50 Pa) that are not normally encountered with naturalor mechanical ventilation. It is the leakage at low pressures (e.g. 4 Pa) that is of interest and it is shownthat the conventional technique leads to large uncertainty in the low-pressure leakage. Ideally apressurisation of 4 Pa should be used, but with the conventional technique the uncertainty due to windeffects is unacceptably large.
When a building is used only for intermittent occupancy, continuous operation of ventilation system isnot necessary for achieving good indoor air quality during the occupation periods. Such buildings havea great energy saving potential which is not harnessed enough yet. Indeed, energy loss can be avoidedby promoting natural means and managing mechanical ones.
In recent years, occupants conduct various behaviors in the appurtenant dressing room, so it isimportant to know the amount of modern moisture production in the appurtenant dressing room.Investigation data showed amount of moisture production caused by the behaviors in the dressingroom did not differ between males and females, and amount of moisture production caused by washingclothes and drying clothes did differ depending on the equipment.
In buildings, favorable growing conditions for mold fungi can occur and cause fungusinfestation. The danger for the occupants of dwellings lies in the spreading of pathogensthrough microorganisms. Mold fungi can occur not only on the surface of external walls, butalso inside construction parts. A prerequisite for preventing mold fungus is the knowledge ofthe transient building physical boundary conditions under which fungus growth takes place.The decisive parameters of influence like temperature, humidity and substrate have to beavailable over a certain period of time simultaneously.
Local control of ventilation in large buildings is considered to be a main issue in energy savings regarding the huge energy losses that are usually induced by such large volumes. An efficient ventilation system and the development of local control ventilation strategies could prevent large buildings from having an unsuited or overvalued ventilation and reduce significantly the energy consumption.
Ventilation is essential for health and comfort of building occupants. It is particularly required to diluteand/or remove pollutants emitted by occupants metabolism. The concentration of metabolic CO2 iswell correlated to metabolic odor intensity. Therefore CO2 concentration can be efficiently chosen asan indoor air quality indicator when occupants are the main pollution source inside the buildings.
Although unanimously acknowledged by the experts for its performances as regards energyeffectiveness and indoor air quality optimisation, humidity sensitive ventilation still too often suffersfrom a lack of knowledge inherent in its singularities. The matter of this article is thus to bring a newlighting on the humidity sensitive ventilation determining airflow rates in the calculations of ductworksdimensioning and in the energy impact related to the air renewal.
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