The California Energy Commission (CEC) has awarded $1.6 million to a multi-disciplinary UC Berkeley-led research collaboration focused on developing innovative, occupant-responsive control systems for heating, ventilation, and air conditioning (HVAC) in buildings. The research program aims to integrate new information technologies into HVAC controls, employing improved sensing and new capabilities for information feedback among the building, its operators, and its occupants.

A paradigm shift on the path of innovation

In early 2012 following extensive successful testing with subjects in climate-controlled chambers, the PIER Program and its State Partnership for Energy Efficient Demonstrations assessed that low-energy personal comfort systems (PCS), developed by UCB's Center for the Built Environment, were ready for demonstration in actual working building spaces. These so-far successful demonstrations of low-energy PCS fan/foot warmers and PCS chairs are in-progress.

While organizing these and other real-life demonstrations, it became clear that even some of the best building heating ventilation and air-conditioning (HVAC) systems were not typically working well enough to take full advantage of the PCS capabilities. Researchers realized that building HVAC controls could be further optimized in a way that was synergistic with PCS deployment. At this time the NSF-funded UCB LoCal project and PIER-funded UCB Cory Hall test bed projects had generated at least one advance in computer science with the potential to facilitate this, the simple Monitoring and Actuation Profile, known as sMAP.

Concurrently, computer science students working on a DOE-funded demand-response demonstration in UCB's Sutardja Dai Hall had spun-off another innovation—a smart phone app that gives occupants temporary control over space conditioning without disruptive effects. This app is thought to have allowed achievement of more energy efficiency and demand response than possible in an environment with less occupant engagement.

At this point a radical idea emerged—HVAC controls might be better designed around occupants and occupant-based technologies, as opposed to the traditional rigid engineering of conditions in building spaces to be consistent with comfort "norms". This "changing the rules" is a paradigm shift synthesizing recent innovations and technology advances, with the potential for deep reductions in energy use accompanied by more occupant satisfaction. The successful proposal for development and demonstration of integrated occupant-based HVAC systems and controls brought together a uniquely qualified team of comfort scientists, building scientists, computer scientists, practicing HVAC control engineers, and demonstration coordinators.

The effort is a joint program of the UC Berkeley Center for the Built Environment (CBE) and the Department of Electrical Engineering and Computer Sciences (EECS), the California Institute for Energy and Environment (CIEE), and Taylor Engineering, a private firm specializing in energy conservation, controls, and systems.

The research will take a comprehensive approach, using new technologies to deliver more comfortable, energy-efficient indoor environments. The program will employ a range of “personal comfort systems” — low-energy fans, foot warmers, heated and cooled office chairs, and other products that provide direct and individualized heating and cooling options for building occupants. It will also integrate an array of fast-emerging information technologies to optimize indoor air-flow, give building occupants more individualized control over temperature and lighting, and poll occupants to gauge their comfort and provide feedback to control systems.

Project leaders predict that these innovations can eliminate 39% of natural gas use and 30% of electricity use for HVAC in typical California commercial office spaces. In California alone, they calculate, the advances could save $62 million in energy costs and reduce carbon dioxide equivalent emissions by some 247,000 tons each year.

Building on advances in technology in many related areas, the project will create and demonstrate new products and operational practices, and promote their adoption into building and energy-efficiency standards, codes, and common practice.

The UC Berkeley campus will be an initial test bed for proving and demonstrating these new products and practices. The diverse types, uses, sizes, and ages of campus buildings and their control systems — combined with UC Berkeley’s targets for deep reductions in energy use — make it an excellent testing ground for project’s planned innovations.

Funding for the research effort is part of the CEC Public-Interest Energy Research program developing energy-efficiency technologies, construction practices, and building operations. The program aims to find cost-effective solutions needed to meet California’s aggressive targets for energy efficiency, zero-net-energy building, and greenhouse-gas reduction.

Lead team members on the project include principal investigator Carl Blumstein (CIEE and i4Energy), co-principal investigators David Culler (EECS and i4Energy), Edward Arens and Stefano Schiavon (CBE), and Gwelen Paliaga (Taylor Engineering); as well as project managers Fred Bauman (CBE) and Karl Brown (CIEE and i4Energy).  

Center for the Built Environment
Taylor Engineering