How to make air turn your home into a comfortable place

The quality of the air

Air is essential for the existence of living beings. In the case of people, it also requires conditions that guarantee hygiene and a state of well-being inside a home. The outdoor air is primarily composed of two elements, Oxygen and Nitrogen, as well as other gases in different proportions such as Carbon Monoxide (CO), Carbon Dioxide (CO₂), Sulfur Dioxide (SO₂), and Methane (CH₄). When these gases do not exceed the values indicated below, the air is considered clean:

• Carbon Monoxide (CO): maximum 1,000 micrograms/m3

• Carbon Dioxide (CO₂): maximum 65.E-4 micrograms/m3

• Sulfur Dioxide (SO₂): maximum 25 micrograms/m3

• Methane (CH₄): maximum 650 micrograms/m3

Unfortunately, in the air of large cities these values are much higher, leading to pollution and the need to filter the air before introducing it into the ventilation systems of buildings. Ventilating means replacing a portion of interior air that is considered harmful due to contamination, with clean air from outside. If the external air is polluted, it will be necessary to purify it using filters placed at points of admission to capture the contaminating elements.

The speed of air

Although it may seem otherwise, air is not a mass of stationary gases, but rather constitutes a thin fluid, turbulent layer constantly moving with a speed that varies depending on the thermal contrasts near the Earth's surface. The massive displacement of large portions of air with a certain speed and common direction is called wind. In turn, the absence of wind near the ground is called calm. The human body has a special ability to perceive air movement, which significantly impacts comfort within an enclosed space. Moving air decreases our thermal sensation in summer, making it a great "refrigerant" for the months in which temperatures are highest. Air displacement at a speed of 0.5 m/s is already slightly perceptible to the human body. The term "calm air" implies movement of up to 0.8 m/s. From this value onwards, the movement of air is perfectly perceived.

The speed of air significantly influences people's comfort, mainly for two reasons: the impact when it collides with them and the noise it produces. In the first case, as previously mentioned, greater cooling occurs due to the air current, allowing a person to feel a lower temperature. The values of air speed in relation to people's well-being can be summarized in the following values:

• Speed of 0 to 0.08 m/s: stagnant air. It produces no effect on the body except for the absence of air.

• Speed of 0.12 m/s: ideal situation, very favorable for cooling areas where high temperatures concentrate.

• Speed of 0.35 m/s: air movement is quite high. It is not recommended in places like offices as it can move small objects like sheets of paper.

• Speed of 0.40 to 1.5 m/s: very high displacement levels. This is the speed of air used for ventilation and air conditioning systems in large spaces.