Influence of temperature and humidity on indoor air quality

Temperature and humidity

Sicrometry is a branch of physics that analyzes the thermal properties of moist air, how they can be regulated, their measurement and the effects of humidity on the comfort of individuals. The humidity contained in the air greatly modifies its physical properties in such a way that it can significantly alter a person's physical sensations. It is said that the air is saturated when it is maintained in equilibrium in the presence of liquid water without any type of transfer occurring. Relative humidity is the quotient between the weight of the water vapor contained in a volume of air and the weight of the saturated vapor for that same volume:
Z (%) = (Weight of Vapor/Weight of saturated vapor) x 100
The temperature, for its part, is a scalar or measurable quantity related to the internal energy of a thermodynamic system. The measuring device is the thermometer in any of its different calibrated forms: Kelvin, Celsius, or Fahrenheit.

Factors that condition indoor air quality

Humidity inside a home affects all its occupants and also the objects and materials it contains. When the air has too much humidity, it condenses into water on cold surfaces such as walls or windows. In this way, it harms its inhabitants due to the presence of mold and bacteria. It also produces noticeable deterioration in the materials and furniture of the house. In this sense, it can be said that indoor air quality depends on:

• The quality of the air provided by the ventilation system coming from the outside
• The composition of the construction materials
• The activities carried out indoors, which condition the rate of renewals (l/h) that should be provided in each room.
• The level of occupation that the building supports, being this another factor that influences the number of renewals per hour
• The indoor temperature
• The humidity of the indoor air

Traditional ventilation systems have employed natural ventilation as a way to renew air quality inside buildings. In the past, the very construction facilitated a spontaneous ventilation through the joints of the exterior walls and the frames of doors and windows. However, starting in the 1970s, countries began to become aware of the need to reduce energy consumption. It was at that moment that, with the significant increase in the airtightness of buildings, the need arose to introduce mechanical ventilation systems that renew the air in a constant and controlled manner. More recently, the advent of dual flow mechanical ventilation has allowed the development of ventilation systems that do not alter the thermal comfort of the interior of a home, thanks to the operation of the heat exchanger. This is capable of transferring heat from one air flow to another without the need for both to mix. In this way, the process of extracting contaminated air is accompanied by the impulse of clean air at the same temperature as the interior rooms.