GNR Heating and Air Conditioning Inc.

Manual J,D Calculations

What are Manual J and D calculation?

A Manual J calculation, takes the construction R-values of your home, and uses them to figure out what size AC and Heating unit is needed. 

A Manual D calculation, takes the same input from your home and designs the duct sizes for each room of your home. 

Information about your house we would need to do a Manual J calculation.

The r-value of the insulation in the walls, and ceiling 
The type of windows, size and orientation
Does it sit on a slab or a crawl space
The direction the  house faces 
The size of the house and its rooms



We have noticed since the adoption of the Manual J,D and other new building codes, that homes built today are more efficient and more comfortable.

If you are building a home and need these calculations, contact us today for more information.

We use Wrightsoft software for our load calculations.

Website Builder