14"W X 14"H [Duct Opening] Aluminum Double Deflection Adjustable Air Supply HVAC Diffuser - [Outer Dimensions: 15.6"W X 15.6"H] Color_White 1/2" White insulation will give

1/2" White insulation will give you a good R value of 3

actual front end outer dimensions are approximately 10 5/8" width X 8 5/8" height

actual front end outer dimensions are approximately 27 5/8" width X 38 5/8" height

+ Product Details Size - 26"w X 8"h is the size for the duct opening measurement only

14"W X 14"H [Duct Opening] Aluminum Double Deflection Adjustable Air Supply HVAC Diffuser - [Outer Dimensions: 15.6"W X 15.6"H] Color_White 1/2" White insulation will give+ Product Details Size 14"w X 14"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 15. 6" width X 15. 6" height. Design Full Control Vertical Horizontal Air flow Direction. Horizontal blades in the front, Vertical blades in the back, both individually adjustable. High Quality Aluminum The premium durable aluminum will never rust and it will never wear through leaving the material with an elegant,