AC replacement in Marshall.

Close to two owner homes in three in ZIP 20115 heat with electricity, 1,357 of 2,109, and that mostly means a heat pump, whose outdoor unit heats and cools and gets replaced as a heat pump, $8,499 to $21,650 for the system. The AC on its own belongs to a smaller group: the 424 houses on propane, the 8 on utility gas, and those of the 160 wood-heated homes that have a furnace for backup. In each of those a furnace heats, a coil set on top of it cools, and when the condenser outside gives out, the furnace can stay right where it is.

Most of Marshall’s houses date from the 1970s through the 1990s. The ZIP counts 532 homes from the 1970s, 605 from the 1980s and 511 from the 1990s, and the County’s plan puts many of the newer streets north of Main Street in those decades, including the cul-de-sacs of Residential North west of Rectortown Road. Houses that age have usually retired their first air conditioner already, and the current one may predate the 2010 cutoff for new R-22 equipment. The 436 homes from the 2000s are the builder-unit case: past fifteen summers, and likely on R-22 if the original is still running.

The old village is another kind of job. Marshall’s National Register district holds 139 properties on 99 acres, from stone, frame and brick buildings of about 1800 to 1835 on West Main Street to story-and-a-half frame houses on Anderson Avenue from the 1920s to the mid 1940s, and 433 homes in the ZIP were built in 1939 or earlier. Central air in those came later, so the condenser may sit wherever a side yard had room. South of Main, the plan notes newer townhouse enclaves around cul-de-sacs, and with 351 attached homes in the ZIP, some condensers share tight strips of ground where a new unit needs the same footprint and clearances.

Marshall sits at about 683 feet, and its storms leave marks on outdoor units. Hail 1.25 inches across fell in Marshall on July 12, 2022, three weeks after the June 22 storm that dropped dozens of trees onto I-66 near the village with gusts estimated at 80 to 90 mph. The June 2012 derecho brought a 61 knot gust at Marshall, and in July 2024 large trees came down on power lines along Bears Den Road. A condenser with hail-flattened fins moves less air across its coil, and on an old R-22 unit that damage usually ends the repair argument.