Make sure your hvac contractor follows these duct design best practices and principles using manual d.
Attic furnace ductwork layout.
A furnace in the attic is a design that works for all homes.
Once all the system variables have been decided your hvac design professional can determine the most efficient ductwork design layout and calculate the correct duct size.
Avoid any hot elements such as water heaters heater or stove.
From these trunk lines come branch ducts usually round that extend.
Route ducts between joists in a basement if possible or over them if necessary.
Place ducts on top of joists in a ceiling or attic.
To account for all the necessary factors many professionals use a tool called acca manual d.
Situate the air handler close to the center of the layout to minimize the length of ductwork spans.
Make the layout as symmetrical as possible with branch ducts spaced evenly along the trunk duct and each branch of similar length.
Unless you have a slab where the equipment would likely be in the garage venting can go directly through the roof instead of routing through an exterior wall making it much easier to install the duct work along the upper floor.
This type of system incorporates the use of a trunk line or series of rectangular ducts that act as a main supply channel throughout the house.
The most common design trunk line layout is provided in the illustration below.