Are you inhaling clean air?

Compared to old wooden houses, the current houses have an airtight structure with less air-replacement. In such houses and condominiums, the amount of air that naturally refills is small. Especially when using heaters such as stoves, windows tend to be closed off, and the air becomes dirty. Chemical substances that volatile from building materials and furniture can cause sick house syndrome, and the concentration of toxic gases generated from combustion equipment such as stoves increases, which may cause carbon monoxide poisoning.
Stop closing and open the window from time to time. If possible, open two or more places and the wind is good and effective. In winter, be sure to maintain your health through ventilation.