ESRA
envelope systems research apparatus
The Envelope Systems Research Apparatus (ESRA) was constructed to expose large areas of
low-slope roof to the East Tennessee climate. The original configuration, shown in the first
photograph below, tested a built-up roof over foam insulation on one half of the ESRA's roof and a
mechanically attached single-ply membrane roof over foam insulation on the other half. Two sides of
the building are mostly below grade while the other two sides are mostly above grade. The ESRA can also
be used to study energy and moisture flow through walls and foundations. Since June 1998, one half of the
roof has been configured to test single-ply membranes with various levels of solar reflectance. Since July 1999,
the other half has been configured to test various low-slope and steep-slope metal roofs, including photovoltaic
test sections. The second photograph below shows the test sections for these experiments, which are described more
fully in the article at http://www.ornl.gov/roofs+walls/research/reflective.htm. The interior of the ESRA is
heated and cooled to constant conditions year round. The ESRA contains a system that does automatic, continuous
data acquisition and houses communications equipment that connects the data system to the Oak Ridge National
Laboratory's intranet. Since January 2000, the interior of the ESRA is the site of the ORNL Hygrothermal
Properties Laboratory. See the article at http://www.ornl.gov/roofs+walls/research/hygrothermal.htm for a
description of this laboratory.
This page updated on May 1, 2001 by Diane McKnight.
)
)