Winter is coming, and we’ve already started seeing some cold nights in the midwest. But what about your furnace? Is it ready for winter? One way to tell is by looking at your filter. While not all filters are created equal, there are some things you can do to ensure... Winter is coming, and we’ve already started seeing some cold nights in the midwest. But what about your furnace? Is it ready for winter? One way to tell is by looking at your filter. While not all filters are created equal, there are some things you can do to ensure...