All ducts shall be installed with a minimum _______ percent slope on horizontal runs up to 75 ft. and a minimum _______ percent slope on horizontal runs greater than 75 ft.

All ducts shall be installed with a minimum _______ percent slope on horizontal runs up to 75 ft. and a minimum _______ percent slope on horizontal runs greater than 75 ft.

• A. 2, 8
• B. 10, 8
• C. 8, 2
• D. 2, 10

Answer: (A)

The test question is about ensuring condensate can drain from ducts by gravity. Ducts laid horizontally must have a downward slope, and the required slope depends on how long the run is. For shorter horizontal runs (up to 75 ft), a minimum slope of 2% is specified. For longer horizontal runs (greater than 75 ft), the minimum slope is increased to 8%. The idea is that longer distances give more opportunity for condensate to accumulate, so a steeper slope helps move the liquid to the drain and prevents pooling, corrosion, or mold. This slope applies to horizontal sections and should direct toward the condensate drain or outlet.

The test question is about ensuring condensate can drain from ducts by gravity. Ducts laid horizontally must have a downward slope, and the required slope depends on how long the run is. For shorter horizontal runs (up to 75 ft), a minimum slope of 2% is specified. For longer horizontal runs (greater than 75 ft), the minimum slope is increased to 8%. The idea is that longer distances give more opportunity for condensate to accumulate, so a steeper slope helps move the liquid to the drain and prevents pooling, corrosion, or mold. This slope applies to horizontal sections and should direct toward the condensate drain or outlet.