The Velocity Protocol
The next morning, the senior engineer, a man named Clark who rarely spoke, reviewed the plans. He traced the duct runs with a yellow highlighter. He stopped at the transition point. He looked at the schedule, then at the McQuay Duct Sizer report Elias had attached. duct sizer mcquay
The McQuay Duct Sizer is a digital version of the traditional duct slide rule. It is designed to help engineers determine the optimal dimensions for ductwork based on specific air volume (CFM) and velocity requirements. It automates the complex calculations found in the ASHRAE Handbook, allowing for quick adjustments to friction loss and velocity parameters. Calculates round and rectangular duct sizes. Determines friction loss per 100 feet. Adjusts for different duct materials and roughness. The Velocity Protocol The next morning, the senior
This is the most common approach for commercial supply and return systems. You select a constant friction loss (usually 0.1 inches of water column per 100 feet) for the entire system. Easy to calculate; ensures consistent pressure drop. He looked at the schedule, then at the
Elias sighed. The velocity was acceptable—anything under 1,500 FPM was generally quiet enough for office space. But 22 inches wide? The corridor he had to run this through was only 20 inches wide between the sprinkler lines and the electrical conduit.
The rain in Seattle didn’t wash things clean; it just made them greyer. Inside the cramped server room of the architectural firm Kensington & Haas , the air was stale, tasting of ozone and old carpet. Elias Thorne, a junior mechanical engineer with a damp trench coat and a growing headache, stared at the exposed guts of the building’s ventilation system.