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
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.
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:
PDF Floor Plan
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 email@example.com and we will get your Manual D taken care of.