With fall officially under way, and winter just around the corner, it’s time to think about filters. Today we’ll give you a filter tip — not for cigarettes — but for furnaces and air conditioners. It’ll help, especially if you’ve got allergies and are sensitive to dust and pollen. From deep within the Carey Brothers’ vault of breathing easy without hacking and wheezing, we bring a breath of fresh air that we hope will be pleasing. When it’s time to change filters in the furnace or air conditioners, some folks use a spray-on filter treatment that increases a filter’s dust-grabbing ability. This soups up the filtering “horsepower” to catch more airborne dust and pollen. But you can do what we Carey Brothers do. Give each filter a good spritz of your wife’s favorite household dust-mop spray. It does essentially the same thing as the special spray — and works, perhaps, even better. And, it’s less expensive, too.