When it comes to formaldehyde, everyone is familiar with it, and we often deal with it in our lives. As a common indoor environmental pollutant, formaldehyde not only has a pungent smell, but is also toxic, which can cause allergic dermatitis, fatigue, insomnia, headache, and also cause harm to the respiratory tract, lungs, cardiovascular system, liver, etc., serious can be life threatening.

And summer can be said to be the golden period of formaldehyde removal, why?

To clarify this question, first of all, let's understand the physical and chemical properties of formaldehyde. Formaldehyde, chemical formula HCHO, formula weight 30.03, also known as formaldehyde. It is a colorless gas with a special irritating odor, which is irritating to human eyes and nose. The relative density of the gas is 1.067 (air = 1), and the density of the liquid is 0.815g/cm³ (20°C). The melting point is 92°C, and the boiling point is -19.5°C. Soluble in water and ethanol. The concentration of the aqueous solution can be up to 55%, usually 40%, called formaldehyde water, commonly known as formalin (formalin), is a colorless liquid with a pungent smell.

Then comes the key question! So many physical and chemical properties of formaldehyde are related to temperature, so what should we focus on today?

That's right, boiling point! Everyone is familiar with the boiling point. Baidu: Boiling is a violent vaporization phenomenon that occurs simultaneously inside and on the surface of a liquid at a certain temperature. The temperature at which the liquid boils is called the boiling point.

So what is the relationship between the volatilization of formaldehyde and the boiling point?

Volatilization means that a liquid becomes a gas below its boiling point and spreads around, which is a physical change. That is to say, the volatilization point of formaldehyde is 19°C, and now we have found the key to the problem. The formaldehyde in the decoration material escapes outward through volatilization. 19°C, 19°C, 19°C, horrible! Say important things three times.

It turns out that when the temperature is higher than 19°C, the amount of formaldehyde released begins to increase, and when it exceeds 30°C, it begins to increase geometrically. Formaldehyde stops volatilizing when it is lower than 10°C. This is why many people are confused. Why do you leave the windows open for 24 hours in winter and still have a strong smell when you check in? This is because the indoor temperature is too low. Formaldehyde does not volatilize at all. Once you move in, close the windows, and the temperature rises, formaldehyde begins to volatilize, and the volatilization is violent, just like the decoration was just finished yesterday.

Why is there such a stark contrast? Let us first analyze the working principle of indoor air pollution, which may be able to solve this mystery. Summer is the most "rampant" season for formaldehyde volatilization. When the room temperature rises by 1°C, the concentration of formaldehyde in the indoor air will increase by 0.15 to 0.37 times. In a room that has undergone room decoration or purchased new furniture within one year, when the temperature rises to 34°C and the relative humidity is 50%, the concentration of formaldehyde in the air is 5.53 times that of usual.

Therefore, summer is the best season for removing formaldehyde, and air purifiers can be used to effectively remove formaldehyde.