Spherical-Motion Average Radiant Temperature Sensor (SMART Sensor)

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Spherical-Motion Average Radiant Temperature Sensor (SMART Sensor)

Princeton Docket # 15-3140


Researchers in the School of Architecture and the Andlinger Center for Energy and the Environment at Princeton University have developed an advanced mean radiant temperature sensor, the SMART sensor, that is cheaper, more applicable, and more reliable than current counterparts. The SMART sensor is able to take an overall global reading of mean radiant temperature while also being able to record weighting for different directions in spherical coordinates. The SMART sensor represents a major advance because typical mean radiant temperature sensors have no directionality in their sensing and cannot provide the user with a spatial image of the radiant temperature profile or provide accurate measurements outdoors due to wind.


The SMART sensor is unique among MRT sensors because it is able to accurately measure MRT in outdoor spaces using a non-contact infrared temperature sensor. As a result, wind has no effect on measurement accuracy. In addition, the single-sensor approach is cheap and effective at accurately measuring MRT. An additional software component that comes with the device maps the thousands of data points recorded by the SMART sensor to the surface of an imaginary sphere. This weighting software can be further customized to provide information on how non-spherical bodies will perceive radiant temperature in a building space. Another unique quality of the SMART sensor when coupled with a LIDAR based rangefinder is the ability to provide the user with a three-dimensional representation of the mean radiant temperature/surface temperature profile in a virtually reconstructed image of the space, information that is useful from a building design perspective.



•       Algorithmically controlled and reliable measure of mean radiant temperature

•       Mean radiant temperature measurements from outdoor spaces, decoupled from wind

•       Produce a spatially-resolved image for leak detection



•       Cheaper than current MRT sensors

•       More reliable than current MRT sensors, particularly in outdoor environments

•       Provides user with a 3D MRT profile of the space

•       Customizable weighting scheme that can provide information about how non-spherical bodies will perceive the radiant temperature



Calabro, E., Teitelbaum, E., Guo, H., Gmachl, C., Penello, G.M., and Meggers, F. Thermoheliodome Testing: Evaluation Methods for Testing Directed Radiant Heat Reflection. 6th International Building Physics Conference, IBPC 2015.


Key Words

Mean radiant temperature sensor (MRT), building technology, outdoor MRT measurements, non-contact infrared temperature sensor, spherical weighting scheme




Forrest Meggers is an Assistant Professor jointly appointed to the School of Architecture and the Andlinger Center for Energy and the Environment at Princeton University. Meggers is also an affiliated faculty member in the Department of Civil and Environmental Engineering at Princeton University. He obtained his Dr.Sc. in Building Systems from the Department of Architecture at ETH Zurich. Before coming to Princeton in 2013, Meggers served as a Senior Researcher and Module Coordinator at the Singapore ETH Centre for Global Sustainability and an Assistant Professor in the Department of Architecture at the National University of Singapore. Meggers has also served on multiple committees for the United States Green Building Council.


Meggers’ current research interests include (1) linking the operation of energy systems and building operations to architectural processes to facilitate more informed building design; (2) improving heat addition/removal efficiency through radiant heating and cooling systems; (3) optimizing building heating/cooling by leveraging thermal gradients in the ground and other phenomena; and (4) designing air systems that minimize temperature gradients and utilizable energy needed to condition air.


Eric Teitelbaum is a graduate student in the department of Civil and Environmental Engineering, advised by Forrest Meggers, conducting research on materials science in architectural settings.


Jake Read is an undergraduate architecture and engineering student at the University of Waterloo and an inaugural member of Professor Meggers' CHAOS Lab.


Intellectual Property Status

Patent applications are pending. Princeton is seeking industrial collaborators for further development and commercialization of this technology.



Michael Tyerech

Princeton University Office of Technology Licensing

(609) 258-6762, tyerech@princeton.edu



Anna Trugman

Princeton University Office of Technology Licensing




Patent Information:
For Information, Contact:
Tony Williams
Princeton University
Forrest Meggers
Eric Teitelbaum
Jake Read