Changing the furnace filter in summer strikes a lot of people as pretty weird. It only takes one good heatwave to make people forget that they even have a furnace, let alone one that needs preventative maintenance in the summertime. Tell them to change the filter in July and, seeing as the furnace is the last thing they want to use right now, they’ll just forget about it. The thing is, the way your (HVAC system) operates makes changing your furnace filter in summer a necessary bit of preventative maintenance ! Here’s why you shouldn’t neglect it, even as the heat pushes to 40 degrees. Air Conditioning and the Furnace: Closely Connected The Importance of the Furnace Filter Most HVAC systems have a lot of ductwork, through which both the cool air from your central air conditioning and the heated air coming from your furnace. The ducts also allow your system to exchange air from outside and within your home. Your system is doing a lot of work using the same pathways, which means tha