Commercial Attic Space Over Ducts

Shown below is an example of what not to do a grille cut into pull down attic ladder and an example of the right way to add a vent a register in the ceiling of garage that connects directly to a roof vent via a metal duct viewed from the attic.

Commercial attic space over ducts.

If the ducting is not sealed well and insulated you will have plenty of problems because of the high attic temperatures. If the ducts must be located within a vented attic one option for protecting the ducts and helping to minimize heat transfer between ducts and the unconditioned attic is to lay the ducts on the attic floor and. They live in a townhome with no attic or basement or crawlspace of any kind. Iv conditioned attic and more.

For homes with ducted heating and cooling systems the best place to locate the duct system from an hvac performance standpoint is within the conditioned space of the home either in dropped ceilings or between floors or in a sealed and insulated basement crawlspace or attic. Combustion air also called make up air can also be provided by a vent through the wall. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. My parents own a home about 40 years old and there is black mold coming from the a c ducts.

They have been told that they need to replace all the ducts. Use metal flex or fiber board ducts that are insulated to code. When hvac ducts are installed in a vented attic in a dry climate bury the ducts in attic insulation to protect them from temperature extremes in the unconditioned attic space. Part of the unit is inside and part is on the roof.

There can be moisture issues in the crawlspace but i would deal with that before choosing to put the ducting in the attic. Ii lowered ceilings in hallways. Iii special trusses that create space below the unconditioned attic. The unconditioned space also houses his hvac system.

The duct insulation should include a vapor barrier cover. Obviously this means a lot of ripping and tearing etc. Ted has more than a few cobwebs in his attic. 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.

Additionally some of the attic space is over an outside deck while other sections are over the house s interior space. Your attic will probably be over 100 hotter than the crawlspace. Why put the ducts there. You can get the air handler and ducts into conditioned space in several ways without needing a basement or crawl space.

When determining how to insulate this attic space various assemblies were taken into consideration and a hybrid combination of vented and unvented attic space was planned. Furnaces ducts and air conditioning ac equipment run throughout the attic spaces on all levels except the dormers and the space over the outside deck. Looking at the cooling side only the additional load would be. I lowered soffits around room perimeters.

R 8 duct insulation 5 227 btu hour.