The home improvement duo at Mason Dixon Acres provides a transparent look at the final technical hurdles of a DIY HVAC startup, from high-voltage wiring to system troubleshooting.

Mini-splits promised to fix home comfort — but the boom created new headaches.

Every technician remembers the first time they encountered a ductless mini-split and the panic they felt inside. Not only do these units look unusual, but they behave to some extent differently from ...