If your air top quality is negative and you also don’t have an air purifier, an HVAC filter taped to some box supporter is much better than nothing. ฝุ่นละออง, เชื้อรา, ละอองเกสร และแบคทีเรีย Corbat recommends finding air purifiers tested and Qualified by AHAM which are given a CADR via the Firm https://mannatureairpurifier.com/