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planning:building_services:ventilation:basics:air_volumes

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planning:building_services:ventilation:basics:air_volumes [2014/09/18 18:19]
127.0.0.1 external edit
planning:building_services:ventilation:basics:air_volumes [2019/01/31 09:46]
cblagojevic [Low indoor air humidities]
Line 105: Line 105:
 **No-one should have to ventilate beyond their comfort level in terms of air humidity**. **No-one should have to ventilate beyond their comfort level in terms of air humidity**.
   * Conventional ventilation designers tend to dimension the air volumes of home ventilation systems as rather high. At times, air change rates of 0.5 or even 0.8 are considered to be necessary, - especially in order to keep the indoor air humidity low in winter, thus reducing the risk of condensation and the associated mould growth.   * Conventional ventilation designers tend to dimension the air volumes of home ventilation systems as rather high. At times, air change rates of 0.5 or even 0.8 are considered to be necessary, - especially in order to keep the indoor air humidity low in winter, thus reducing the risk of condensation and the associated mould growth.
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   * In Passive Houses, both problems do not occur anyway, because due to the good level of thermal protection, all interior surfaces of external components are so warm that even at 60% indoor air humidity, condensation cannot occur. Therefore, the external air quantity can be decreased slightly in cold periods, particularly if indoor air humidity is felt to be too low by the occupants. **Ventilation system air changes between 0.3 and 0.4 are "​reference values"​**. For Passive Houses we generally recommend that air volumes should be based on these lower values, so that with good air quality, the indoor air humidity also remains within the comfortable range.\\   * In Passive Houses, both problems do not occur anyway, because due to the good level of thermal protection, all interior surfaces of external components are so warm that even at 60% indoor air humidity, condensation cannot occur. Therefore, the external air quantity can be decreased slightly in cold periods, particularly if indoor air humidity is felt to be too low by the occupants. **Ventilation system air changes between 0.3 and 0.4 are "​reference values"​**. For Passive Houses we generally recommend that air volumes should be based on these lower values, so that with good air quality, the indoor air humidity also remains within the comfortable range.\\
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planning/building_services/ventilation/basics/air_volumes.txt · Last modified: 2019/03/20 10:58 by cblagojevic