Conference article

Duty Cycle for Low Energy Operation of a Personal Conditioning Device

Rohit Dhumane
Center for Environmental Energy Engineering, University of Maryland, College Park, 4164 Glenn L. Martin Hall, Bldg., MD 20742, USA

Jiazhen Ling
Center for Environmental Energy Engineering, University of Maryland, College Park, 4164 Glenn L. Martin Hall, Bldg., MD 20742, USA

Vikrant Aute
Center for Environmental Energy Engineering, University of Maryland, College Park, 4164 Glenn L. Martin Hall, Bldg., MD 20742, USA

Reinhard Radermacher
Center for Environmental Energy Engineering, University of Maryland, College Park, 4164 Glenn L. Martin Hall, Bldg., MD 20742, USA

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Published in: Proceedings of the 12th International Modelica Conference, Prague, Czech Republic, May 15-17, 2017

Linköping Electronic Conference Proceedings 132:86, p. 791-798

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Published: 2017-07-04

ISBN: 978-91-7685-575-1

ISSN: 1650-3686 (print), 1650-3740 (online)


The Roving Comforter (RoCo) is an innovative personal thermal management technology that provides ultimate personal thermal comfort for individuals in inadequately or even unconditioned environments. It is a miniature heat pump system mounted on a robotic platform capable of autonomously following individuals to deliver comfort by directing hot or cold air through automatically controlled nozzles. This allows buildings to relax their thermostats upto 4 degrees Fahrenheit without sacrificing occupant comfort, leading to energy savings anywhere between 10 to 30% depending on climatic conditions. RoCo, a portable device, operates fully on an onboard battery pack which therefore has to be carefully designed to balance power output, operating time and weight. To address this challenge, a multi-physics model that is capable of simultaneously simulating thermodynamics, electricity and mechanics of RoCo is developed and two duty cycles are analyzed. By observing and analyzing the simulation results, control strategies related to RoCo operation are proposed.


Battery, Air-conditioner, Duty-cycle


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