Whole-home humidifiers in Triangle.

Triangle is small, about two thousand owner homes, and almost half were built after 2000. Six in ten are detached. The newer ones are tight, with big finished basements and gas furnaces, and they need a modest humidifier set conservatively. The older ones, about one in six built before 1960, are a separate case.

Three quarters of owners here heat with gas, one of the higher shares around, and that makes the bypass Aprilaire the standard answer. The furnace is usually in an unfinished part of the basement with a water line and a floor drain within a few feet. It’s about as easy as a humidifier install gets. Along the newer streets off Route 1, a builder-grade furnace and a straight, short duct trunk are the norm, and short trunks carry humid air well.

The older houses near Route 1 have a different story. They leak air, their ducts may have been added decades after the house, and the furnace could sit in a crawlspace. We look at the access before promising a clean install, and we say so if a room unit makes more sense. On some of those older lots the furnace may sit in a low crawlspace, and a water line there needs real care in a hard freeze.

Prince William Water serves Triangle with Occoquan Reservoir water, treated at the Griffith plant. We don’t have a hardness number for the town, so we treat it like any public supply and show you how to check the pad midwinter. If the builder’s humidifier is already on the furnace, the $99 visit tells you if it can be revived.