Furnace and AC replacement in Reston.

Line up Reston’s owner homes by age and the middle lands on 1981. About three in ten of all its homes went up in the 1970s and more than one in five in the 1980s. A house from those years got its furnace and air conditioner the same week, and when the builder’s pair wore out, the two often went together. So in many 1980s houses the pair there now is a second set from the 2000s, in the 1970s clusters often a third, each running on one clock again.

That timing matters because of the refrigerant. New air conditioners and heat pumps built with R-22 were barred from 2010, so a set from before then most likely runs on it, and a leak at fifteen to twenty years old is where repairing stops making sense. Price the pair on a mild spring afternoon, not in a heat wave.

North Point shows it best. More than eight in ten 20194 homes date from the 1980s and 1990s, about a third single-family houses and a third townhouses, and about two in three of their owners heat with gas. In 20191, around Hunters Woods and South Lakes, about six in ten owners heat with electricity instead, so there the same decision is usually about a heat pump and its air handler.

The outdoor half is the part Reston Association watches. RA skips the application for a replacement when the new unit goes in the approved spot, measures four feet tall at most and carries a sound rating no worse than the old one’s. Some higher-efficiency outdoor units stand taller than the 1990s models they replace, so we check height and decibels against RA’s test before anything is ordered.