Air duct cleaning in Dumfries.

Inside the Town of Dumfries, homes split almost exactly between single-family houses and townhouses, about four in ten each. That’s two different duct layouts in one small town, and each gets opened and photographed its own way before anyone names a price.

The townhouse rows went up together: Town records date Williamstown to 1974 through 1991, Port O’Dumfries to 1974 through 1988, and South Cove to 1988 through 1992. With about half the Town’s owners heating by electricity, many of those units run a heat pump with the air handler in a closet or the attic, a short trunk, and often a single return grille in the hall pulling air from the whole floor. That grille and the stretch of duct behind it are where the camera goes first.

The single-family streets are older. About four in ten Town homes went up before 1980, and Town records date Whitehaven’s houses from 1930 on and Tripoli Heights from 1950 on. A house that age often had its ducts laid out for a furnace alone, with central air pushed through the same runs years later, and its metal trunk in the basement or crawl space has had decades to collect what the filter missed. The camera photos show that trunk’s joints and low spots before we price it.

Outside the town line the houses get newer. Montclair is about three in four single-family houses with a median built in 1989, and the larger ones there may carry a second system for the upstairs, each its own cleaning. Cherry Hill, covering most of 22026 outside the Town, has a median home built in 2005, about four in ten townhouses, and plenty of flexible duct, which we brush more gently than metal.