Heated and cooled chairs for comfort and energy efficiency on campus
TGIF Award: $29,869.00
Project Theme: Sustainable Buildings
Project Sponsor: Center for the Built Environment (CBE)
Personal comfort systems (PCS) offer both comfort and energy benefits. Buildings contribute 40% of the total US greenhouse gas (GHG) emissions primarily through their heating, cooling, and ventilation (HVAC, air conditioning). Facing climate change, it is essential that HVAC systems become both more energy-efficient and more resilient.
The comfort requirements of individuals differ by 2 – 5 degrees C due to their gender, age, body mass, clothing habits, metabolic rate, and thermal adaptation. For this reason, less than 80% of occupants are thermally satisfied in jointly occupied spaces. Building operators futilely attempt to solve this by maintaining narrow HVAC temperature setpoint ranges, at great energy cost. If it were possible to expand the temperature range in which all occupants are comfortable, operators could reduce HVAC energy consumption by roughly 10% per degree C of setpoint relaxation in either direction. PCS make possible over 3 degrees C relaxation so save at least 30% of heating and cooling energy. (PCS itself uses only one or two percent of the building’s HVAC energy; insignificant in comparison to the HVAC savings). At the same time PCS allows all individuals in a given space to be comfortable, including both the warm- and cold-sensitive ones. In a six- month field study of 40 occupants in a major county office building, the chair delivered 97% thermal satisfaction, much higher than is observed in conventional buildings. Finally, the PCS adds to a building’s resilience because it reduces HVAC intensity under extreme outdoor temperatures, and can continue to operate during power outages.
1) Demonstrate the comfort effects of heated/cooled chairs for UCB students, and
also their energy benefit, in a library space, a common room in a dorm, and an open-plan office space.
2) Encourage campus-wide adoption of PCS. 3) Design and fabricate 10 battery-powered heating/cooling cassettes that convert chairs on UCB’s purchase list to PCS; this approach will facilitate future dissemination of heated/cooled chairs because the cassettes can be manufactured stand-alone and implemented broadly (as at Cal) until chair manufacturers begin to adopt the technology in integrated products.
Project Lead: Hui Zhang, firstname.lastname@example.org