Residential Attic Ductwork Layout

Well in the comments dave roberts a senior engineer at the national renewable energy lab nrel wrote about a paper he co authored last year and included a link to it.

Residential attic ductwork layout. The residential forced air duct system. Situate the air handler close to the center of the layout to minimize the length of ductwork spans. The attic ductwork is flex duct work. 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.

Number one is the heating and cooling load calculation using a protocol like acca s manual j or the ashrae handbook of fundamentals. Duct system design considerations part 1 by roger m hensley cms. Route ducts between joists in a basement if possible or over them if necessary. Aging ductwork can compromise your system s optimum performance efficiency and air quality.

Most residential structures can accommodate one or more of these configura tions. From these trunk lines come branch ducts usually round that extend. Place ducts on top of joists in a ceiling or attic. Often residential ductwork from the original construction was designed inexpensively and without much thought for longevity.

You ve got to know how much heating and cooling you need for each room in btu hr. Look at the following factors when assessing your aging ductwork design. It was new when the ac was put in 7 years ago. Designing a duct system is important but there are a few critical steps that come first.

To account for all the necessary factors many professionals use a tool called acca manual d. Ductwork is simply an air delivery system. I called out the original hvac company and they took a look and said they saw no water. Up against the deck may be the worst place in the attic to.

The most common design trunk line layout is provided in the illustration below. Typical trunk and branch duct systems. The layout and installation of the duct system will incorporate these basic principles of good ductwork design. One of the most important jobs of the designer.

Make the layout as symmetrical as possible with branch ducts spaced evenly along the trunk duct and each branch of similar length. 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. Remember that article i wrote about ducts installed against the roof deck and how i said it was probably the absolute worst single location for installing ducts. This hvac for beginners section begins here with a discussion about forced air duct systems the basics the how and why of duct sizing.

When were the ducts installed. Recently i had another hvac company come out and put in a new bathroom vent and they told me they believed the duct work was full of water. Avoid any hot elements such as water heaters heater or stove.