HOME PRODUCTS RESOURCES ABOUT CAREERS NEWS TRADE SHOWS CONTACT Thermaflex® PHD Flexible Air Duct Patent pending Thermaflex PHD flexible air duct is energy efficient, environmentally friendly and cost effective. Made with 100% recyclable inner core and vapor barrier, PHD is a great choice for LEED projects and applications where sustainability is key. The non-metallic construction of this versatile duct also makes it ideal for MRI and clean rooms. Watch the Thermaflex PHD video . PHD Specs Diameter 4-12 inches ID Pressure Rating (WG) Positive 10 inches (4˝-12˝ ID) Negative 1/2 inch (4˝-12˝ ID) Velocity 5000 FPM Temp. Range -20°F – 250°F cont. R-Value R-8.0 = 2.25″, .74 lb./ft3 minimum density fiberglass blanket. Downloads PHD Product/Submittal Sheet Products Thermaflex® Pro Series Insulated M-KC M-KE G-KM PHD Non-Insulated S-TL S-LD S-LP-10 EverClean™ Flex-Vent Insulated Floating Core (FC) KM KP KPE R-KD Non-Insulated MC DV Accessories Flexible Duct Assemblies FlexFlow Elbow FlexaBoot FlexTie Thermasleeve Snaplock Clamp SISTER COMPANIES AFFILIATES © 2021 THERMAFLEX | Anti-Modern Slavery & Transparency