Attic Space Vs Plenum Space

The plenum truss bulkhead adds only the amount of inside conditioned space required to house the ductwork by modifying the roof framing to create a boxed in area in the otherwise unconditioned attic.

Attic space vs plenum space.

Many projects will use non plenum cabling to save on costs. I wonder if the nec definition of the word plenum would actually apply to the entire attic space. Space between the suppended ceiling and the insulted roof is the return. The energy savings touted by unvented attics can be as high as 20.

You will have a suppended ceiling showing in room then you have a fire wall sheeting covering the who attic area from the rooms and then the roof structure well insulated. However it is ultimately up to the building owner or the goverment codes and regulations on whether or not to use plenum vs. Insurance issues may also have an impact on the chose of plenum vs. Duct through corner of closet from attic back to crawl to circulate dry attic air and close the foundation vents.

Place 40 ft drainage pipe with holes across center floor of dirt crawl space attach this to duct line to attic space with an inline 90 cfm silent exhaust fan at the other end of attic run a 6 in. It s easy to see your point about eliminating ductwork from the attic. A basement is below and an attic is above the main part of the house. However if moisture is able to enter the unvented attic space it may lead to roofing panel issues.

Unventilated attics can help to mitigate energy loss through leaky ducts or ceiling fittings. The velocity of the overall air movement within the two spaces would be substantially different at the same cfm. However i have two questions if i want to centrally air condition my entire house. However some drop ceiling designs create a.

A two room addition on the 1st floor has limited attic space and a 4 crawl space. Now this 2 foot space for return air is sealed off to the outside air and air tight for fire problems. Space between the structural ceiling and the dropped ceiling or under a raised floor is typically considered plenum.