ventilation is a must to prevent moisture and pollutants accumulate. if you do not ventilate enough, this leads to mold and dust mites, and you also have to cope with health problems, such as shortness of breath and coughing. with natural ventilation (eg open up windows) you come to an end, but many homes are well insulated to thereby suffice.mechanical ventilation in such a case the solution.
번역되고, 잠시 기다려주십시오..