The nature kingdoms suggested a grapefruit room freshener from the health food store to be sprayed into the air handler. 自然王国建议用一种来自健康食物店的柚子空气清新剂来喷洒到车子的空气处理系统中。
However, air ducts and air-handling equipment require more space than pipes and pumps, ductwork is hard to seal, and leaks are difficult to detect. 然而，空气管和空气处理装置比起管道和泵需要更多空间，管道系统很难密封，泄漏很难发觉。
