House Attic Ductwork Layout

The 2nd duct is the return duct that attaches to the return air vents and draws the stale air out of the house through the filter and conditions it again to return to the house as conditioned air through the supply duct system.

House attic ductwork layout.

The unconditioned space also houses his hvac system. Make the layout as symmetrical as possible with branch ducts spaced evenly along the trunk duct and each branch of similar length. The most common design trunk line layout is provided in the illustration below. Make sure your hvac contractor follows these duct design best practices and principles using manual d.

When beau called me we discussed the job and i said to him son you ve got to give this homeowner hope. The layout and installation of the duct system will incorporate these basic principles of good ductwork design. Place ducts on top of joists in a ceiling or attic. Number one is the heating and cooling load calculation using a protocol like acca s manual j or the ashrae handbook of fundamentals.

Ted has more than a few cobwebs in his attic. Route ducts between joists in a basement if possible or over them if necessary. To promote balanced air circulation through the supply ducts home and return ducts the ductwork should be simple in layout accurately sized sealed insulated in unconditioned spaces and installed in the right places. You ve got to know how much heating and cooling you need for each room in btu hr.

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. Avoid any hot elements such as water heaters heater or stove. Situate the air handler close to the center of the layout to minimize the length of ductwork spans. Designing a duct system is important but there are a few critical steps that come first.

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. Runs that are too long. 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. Up against the deck may be the worst place in the attic to.

That may require long runs of ductwork that make it hard for your hvac system to move conditioned air to certain areas within the space. Ductwork design mistake 2. The 1 800 square foot brick ranch in climate zone 4 dates from the 1960s but the previous owner installed both a furnace and ductwork in the attic just four years ago.