ACCA Manual D Reports

The Air Conditioning Contractors of America's (ACCA) Manual D

is the ANSI-recognized industry standard for designing and sizing your home's HVAC duct system(s).

Comfort Geeks is Southern Arizona’s ACCA Manual D duct system performance expert, and our duct systems outperform the rest — on paper and in homes. Leverage our industry expertise for duct systems that maximize ventilation performance and minimize airflow noise.

What is a the ACCA Manual D?

The ACCA Manual D standard is the scientific process for designing and sizing home duct systems. Manual D ensures your HVAC system can provide adequate air distribution for quiet, consistent indoor comfort. Closely related is ACCA Manual T, which pertains to the proper sizing and selection of HVAC registers and grilles.

When is ACCA Manual D required?

A Manual D duct system performance report is required to obtain a (ducted) HVAC system installation permit for new construction, addition, or major remodel projects in southern Arizona (and most other municipalities across the US).

If your HVAC contractor isn’t using ACCA Manual D to size your duct system, they’re gambling with your indoor comfort at stake.

Manual D Report FAQs:

(click/tap the + next to the Q to reveal the A)

Why is ACCA Manual D important?

Your indoor comfort, air quality, and HVAC system’s efficiency depend on a properly designed duct system.

What if my designer/contractor doesn't use ACCA Manual D?

Designing a duct system without ACCA Manual D is like driving your car with your eyes closed. You can cross your fingers and hope for the best, but the odds of a successful outcome are slim. How do we know? Because we’re in homes fixing these horrific duct systems every week!

How will ACCA Manual D keep my HVAC system quiet?

ACCA Manual D specifies minimum and maximum velocities (air speeds) for different duct types and functions, allowing a skilled mechanical designer to minimize airflow noise while maximizing ventilation and system performance.

I've heard that flex ducts are bad for airflow. Is that true?

Not really. Air moves differently through flexible ducts than rigid ducts or because the material friction rates differ. Like every other duct system type, the key to an amazing-performing ventilation system is proper design and quality installation. Flexible ducts must be appropriately sized and supported, routing should avoid kinks and sharp bends, and there shouldn’t be any extra slack or sagging.

Does using a high-efficiency air filter have any impact on Manual D?

Yes, absolutely. High-MERV filters have higher pressure drops (airflow resistance) that change how your HVAC system blower and duct system perform. Adding a high-efficiency filter to a duct system not originally designed to support it can result in comfort and efficiency loss and damage to expensive HVAC system components.

More questions about ACCA Manual D Reports? Drop us a line!