The NRCA Leadership and Workforce Development Catalog now is available for download.

A cathedralized attic in a hot humid climate - is it worth conditioning?

To obtain a copy of a specific publication, users should contact the publication's publisher directly.

Abstract
Cathedralized attics in energy efficient homes in hot humid climates provide a hospitable, performance enhancing environment for air handlers and ductwork. This is because a well insulated, airtight building enclosure is constructed at the roof line and indoor temperature and humidity levels are not near outside levels. Although cathedralized attics with space conditioning systems located within them are not typically provided with dedicated supply and return air, it is not clear if more energy would be saved if the space, and the air distribution system in it, were directly conditioned thereby turning the space into a conditioned mechanical room. Or would the energy cost of directly conditioning the space negate the possible air distribution system performance benefits that result from the system being in a directly conditioned space? Research is ongoing at a Building America house built in 2005 in Orlando, Florida that has a cathedralized attic. The attic contains dedicated supply and return air ductwork that can be activated remotely and is alternately directly conditioned and indirectly conditioned for several weeks at a time. Temperature and humidity monitoring sensors within the attic space and the living space below provide comparative information on the conditions within both spaces. Results of measurements taken during cooling conditions and the analysis of the energy performance of the air distribution system during directly conditioned and indirectly conditioned cases indicate that marginally more energy is used when the cathedralized attic is directly conditioned. When the attic was directly conditioned during cooling, over-cooling occurred periodically in one of the living spaces. Similar circumstances occurred when the attic was directly conditioned during heating.
Date
12/2007
Author(s)
John Broniek
Page(s)
Keyword(s)
cathedralized attic; conditioned air; humid


Note: Documents in this section are provided as Adobe Acrobat PDF files. In order to print and view PDF files, the Adobe Acrobat Reader software/plugin, which runs on Microsoft Windows, Macintosh, OS/2 and various versions of UNIX, must be installed on your computer. Adobe Acrobat Reader is available for download as freeware from Adobe Acrobat's website. Please note that the resolution of on-screen versions is not as high as printed versions of PDF files.

Advertisement

Subscribe for Updates Join 25,000+ roofing professionals following NRCA

Subscribe to NRCA