Ensure combustion air is good enough; adding intake ducts or grilles can building up furnace expenses yet is standard for safe
https://padlet.com/chastityrbuck1ynctw/bookmarks-ca96hnvopfxcz8mu/wish/do3MQJPg9wr5W15w
Ensure combustion air is sufficient; including intake ducts or grilles can bring up furnace charges but is important for safe, green operation.