What is Manual D?

Duct design is a standard for specifications and design of the supply and return of your HVAC System. Manual D calculations help insure that the heating and cooling created by your HVAC system reach each room efficiently based on the Manual J and Manual S calculations.

After you have your Manual J and Manual S created the next item that may be requested of your is a Manual D residential duct design. A manual d can be used on a home alteration, addition, or new home construction. Proper duct sizing is important to make sure the heating and cooling loads of each room in your house are properly satisfied.

A Manual D duct design uses the following data

Manual J Total Heat Loss

Free Manual J

Manual J Total Heat Gain

Total Square Footage

Manual S Sizing of the HVAC Unit

Manual S CFM per ton

Manual S total CFM

CFM per square feet

Component Pressure Loss

Available Static Pressure

Longest Supply Run

Longest Return Run

Name of the Room being heated and cooled

Square footage of the room being conditioned

Required CFM of the conditioned room

Size of the supply duct

Size of the return duct

Total Room Heat Loss

Total Room Heat Gain

This Manual D calculation then gives the contractor, inspector, homeowner, subcontractor, architect, engineer, and anyone involved in the project a look at sizes and needs of each room in the structure. This is typically required before permitting of a structure but could sometimes be suggested after the fact if a building inspector wants more insight on how the proposed HVAC system is going to be installed.

What Does a Manual D Cost?

A Manual D is typically composed of a section of calculations and floor plan that shows which rooms will be heated and cooled. These rooms on the Manual D layout are listed in the calculations so that someone looking at each page of the Manual D could cross reference the other section and find the data they need to install the HVAC duct work correctly.

Ductwork in the home is one of the most important system as it delivers the hot and cold air that everyone needs to stay comfortable. The Manual J measure the heat loss and gain, the Manual S sizes the HVAC equipment and the Manual D is the logistics needed to deliver that conditioned air to the end user. This conditioned air than adds to the enjoyment and livability of any structure.

Some items that you need to complete a Manual D:

Manual J

Manual S

PDF Floor Plan

Jobsite Address

Square Footage

Manual D Software, Sliding Scale, ACCA Spreadsheet, or hand calculation capabilities

Having all these items together will allow you to begin on your Manual D. We can create a Manual D for your in about 4-6 hours on most structures. We charge $99. You can email your Manual J, Manual S, PDF plans, jobsite address, and square footage to plans@manualjs.com and we will get your Manual D taken care of.

What is a Manual J?

What is Manual S?

Review Date
Reviewed Item
Manual D Calculation
Author Rating
Software Name
Software Name
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Software Category
Manual D Residential Load Duct Sizing Calculation PDF

Email order number, PDF Plans, jobsite address, and square footage to plans@manualjs.com