Roof Thermal Research Apparatus (RTRA) and Envelope Systems Research Apparatus (ESRA)

The Roof Thermal Research Apparatus (RTRA) was constructed for documenting the effects of long-term exposure of small, low-slope roof test sections to the East Tennessee climate. The RTRA has four 4 ft by 8 ft openings in its roof to receive different instrumented low-slope roof test sections. Each test section comprises one to eight configurations. Its original use showed the in-service aging effects with CFC and alternative blowing agents for polyisocyanurate foam boards in roofs covered by black and white membranes. These test sections are shown in the photographs below. More recent use of the RTRA has been to document the thermal performance of low-slope roofs coated with reflective coatings. In June 2000, we completed a three-year study with the support of the Roof Coatings Manufacturers Association. The thermal performance of 24 different roof coating systems was monitored simultaneously.

Roof Apparatus


The Envelope Systems Research Apparatus (ESRA) was constructed to expose large areas of low-slope roof to the East Tennessee climate. The ESRA is used to study energy and moisture flow through walls and foundations. 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.