Rotatable Guarded Hot Box

The Future Of Wall Testing Capabilities

 

Oak Ridge National Laboratory (ORNL) operates and maintains a guarded hot box that is used to measure the thermal conductance (R-value) and thermal transmittance (U-Factor) of full size wall and window assemblies. The Rotatable Guarded Hot Box (RHGB) is unique in that the entire apparatus can be tilted so that the test specimen can be evaluated at vertical or horizontal orientations and at any angle in between. The box operates under the requirements of ASTM C 163-97.

Test assemblies are installed into a a specimen frame which is mounted on a moveable dolly. The specimen frame has an aperture of 13-ft long by 10-ft high. The specimen frame/test assembly is inserted between two "clam-shell" chambers of identical cross-section. The placement of the test wall assembly between the chambers allows the chamber temperatures to be independently controlled, thereby creating a temperature difference across the specimen. The chambers are designated as the climate (cold) and metering/guard (hot) chambers. The following photograph shows the RGHB.

The climate chamber (cold side) is equipped with blowers and an air-conditioned system capable of producing stable environmental conditions.

©2004 Oak Ridge National Laboratory