Abstract
Saving energy in buildings is top of mind with today’s
building professionals. Although designing energy-efficient
walls and roofs is mostly a no-brainer, ensuring
that below-grade foundations do not generate moisture problems
has become even more complex, particularly because of
how soil is involved.
Hygrothermal performance of soils coupled to buildings
is complicated because of the dearth of information on soil
properties. A computational approach for heat transfer through
the ground has been well-defined, and simplified methods have
been developed. These approaches, however, generally ignore the
transfer of soil moisture, which is not negligible.
The intention of an ongoing study at Oak Ridge (TN) National
Laboratory, therefore, is to gather, comprehend and adapt soil
properties from soil science as well. The obtained information
must be applicable to related tasks in building science and validated
with hygrothermal calculation tools, where additional plugins
to the existing software code—WUFI (an acronym for Warme
unde Felichte Instructionar, which translates to unsteady heat and
moisture)—are required. (See the sidebar, opposite page, for specifics
on WUFI.)Simulation results from WUFI are being compared
with existing thermal-only measurements and are being accomplished
with ongoing hygrothermal measurements.
The final outcome of the study will be the evaluation of several
soil types in several climate zones for a number of basement
assembly types. The study will define the type of soil, together
with the type of building construction considered most and least
reliable with respect to energy consumption and moisture safety.
Furthermore, the study will determine the influences that different
soils have on total energy loss through the ground.