IGSHPA Installer Accreditation Versus Vertical Loop Installer (Driller) Accreditation In the past, we’ve written a few articles about what exactly the IGSHPA accreditation is, if it’s worthwhile, and when contractors should get it. The International Ground Source Heat Pump Association (IGSHPA) now has a separate program for drillers, called “Vertical… Continue reading “IGSHPA Installer Accreditation Versus Vertical Loop Installer (Driller) Accreditation”