Ventilation in a buildings with high moisture load
Matveev, Roman (2012)
Mikkelin ammattikorkeakoulu
2012
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-201302092214
https://urn.fi/URN:NBN:fi:amk-201302092214
Tiivistelmä
Excess moisture content in the air is a main reason of damage and destruction of buildings, especially in Russian conditions. High relative humidity has significant effect during storage various types of materials and products.
Relative humidity fluctuations are often the most important factor causing instability of properties of materials. Problems associated with high relative humidity of air are often neglected in the design and construction of buildings.
Aims of this bachelor thesis are to discuss negative influence of high relative humidity, existing methods of removing moisture from air, air flow rates calculations, and operational costs of different dehumidification methods.
Basic idea of space dehumidification is to remove moist indoor air and to bring dry air into the space. When dry air comes into the space, it mixes with moist indoor air, and due to this mixing relative and absolute humidity of indoor air decreases.
Main moisture sources in the buildings are: open water surface, wet floors and walls, equipment, people. Calculations of air flow rates are based on the moisture emissions.
There are three main methods of air dehumidification: condensation, adsorption and ventilation methods. Each method has own features, complexity, capital and operation costs. Air in the space can be replaced by recirculation air, dehumidified in the air handling unit, or by outdoor air in winter time without dehumidification, and with dehumidification in summer time.
Calculation of moisture emissions, air flow rates and power consumption of different dehumidification methods are on shown for the study case. Most power consuming method was ventilation in winter time, most energy-efficient was recirculation of indoor air with dehumidification by condensation method.
Relative humidity fluctuations are often the most important factor causing instability of properties of materials. Problems associated with high relative humidity of air are often neglected in the design and construction of buildings.
Aims of this bachelor thesis are to discuss negative influence of high relative humidity, existing methods of removing moisture from air, air flow rates calculations, and operational costs of different dehumidification methods.
Basic idea of space dehumidification is to remove moist indoor air and to bring dry air into the space. When dry air comes into the space, it mixes with moist indoor air, and due to this mixing relative and absolute humidity of indoor air decreases.
Main moisture sources in the buildings are: open water surface, wet floors and walls, equipment, people. Calculations of air flow rates are based on the moisture emissions.
There are three main methods of air dehumidification: condensation, adsorption and ventilation methods. Each method has own features, complexity, capital and operation costs. Air in the space can be replaced by recirculation air, dehumidified in the air handling unit, or by outdoor air in winter time without dehumidification, and with dehumidification in summer time.
Calculation of moisture emissions, air flow rates and power consumption of different dehumidification methods are on shown for the study case. Most power consuming method was ventilation in winter time, most energy-efficient was recirculation of indoor air with dehumidification by condensation method.