ACCA Manual D • Duct Design
Duct design that delivers quiet, balanced comfort—room by room.
Movement Energy Inc designs duct systems using building-science principles and ACCA Manual D methods to support efficient airflow, proper static pressure, and California-ready performance.
What Manual D duct design covers
Manual D is the duct-design companion to Manual J (loads) and Manual S (equipment selection). It turns your required room-by-room airflow into a duct layout that can actually deliver it—without excessive noise or pressure problems.
We design supply and return paths, size trunks and branches, and verify friction rates and total external static pressure (TESP) targets so the system performs as intended in the real world.
Why it matters
Better ducts = better HVAC performance
Even the best equipment can’t overcome poor airflow. A Manual D–based design helps protect comfort, efficiency, and equipment longevity.
Balanced room temperatures
Right-sized branches and properly planned returns help reduce hot/cold rooms and improve mixing.
Lower noise & fewer callbacks
Velocity and pressure checks help avoid whistling grilles, rumbling returns, and comfort complaints.
Efficiency you can measure
Correct static pressure and airflow support rated performance—especially important for heat pumps and high-efficiency systems.
Our approach
Our Manual D workflow
A clear, documented process—built for transparency and California standards.
1) Inputs from Manual J & Manual S
We start with room-by-room loads and selected equipment airflow targets so the duct design matches the system.
2) Layout + supply/return strategy
We map duct routes, register locations, and return pathways to support comfort, filtration, and low noise.
3) Sizing + friction rate checks
We size trunks/branches, verify friction rates, and account for fittings, transitions, and equivalent lengths.
4) Static pressure & deliverables
We review pressure budgets and provide a clear design package (notes, schedules, and assumptions) for installation and verification.