RectorSeal’s Outset Seal, an adjustable lineset protection system for ducted and ductless HVAC installations, is designed to protect indoor areas by blocking air leakage, moisture penetration and rodent intrusion and hiding unsightly wall penetrations where HVAC linesets enter or exit structures.

I first encountered formic acid erosion/corrosion when our installed air conditioning and heat pump evaporator (indoor) coils began suddenly leaking refrigerant in 2008. These were not old coils either, and some had only been installed for a year when the issues arose.