Anybody who has ever spent time in an office knows that workspaces run hot and cold—for any number of reasons. The ventilation may vary, even in adjacent cubicles. The employee who has access to the thermostat thinks “comfort setting” means sweat lodge. Or, conversely, a woman experiencing hot flashes prefers temperatures suitable for a meat locker.
Now, researchers at the University of California–Berkeley Center for the Built Environment (CBE) are working to take research innovations from their labs into the real world that will give office workers an unprecedented sense of control over their thermal environments—and will cut commercial building energy consumption by close to one-third.
Personal Comfort System
Armed with a recently announced $1.6 million grant from the California Energy Commission (News - Alert), the researchers are developing a set of tools that will facilitate more efficient temperature control in buildings by using:
- Input from building occupants,
- A network of Web-based applications, and
- A user-responsive personal comfort system (PCS) embedded in office furniture.
A workspace equipped with a personal comfort station might offer a variety of low-wattage devices—such as a foot warmer on the floor or a heated chair, and small, finely directed fans— all of which can be turned on or off quickly and easily to warm or cool individual users on demand.
Above, infrared images of the head of a thermal test mannequin change from red to yellows and greens as the personal comfort system switches into cooling mode. (Courtesy of the Center for the Built Environment)
The PCS system will be designed to target the most thermally sensitive parts of the body—such as the face and head, and the torso and feet— to provide warmth or cooling as needed and as desired, rather than trying to maintain one temperature for an entire building or floor.
“It’s even better than having a thermostat at every workstation, if that were possible,” said Edward Arens, the project’s co-principal investigator, and a professor of Architecture and director of CBE.
A workstation equipped with a personal comfort station features a foot warmer on the floor and small, finely directed fans so occupants can adjust their workspace temperature. (Courtesy of the Center for the Built Environment)
Interfaces with Smartphones, Software, Sensors
The personal comfort system’s heating and cooling tools also will be designed to interface with smartphone apps, software, and sensors, in order to relay building temperatures, weather forecasts, and thermal satisfaction responses to the people who currently make decisions about energy use in the building.
The PCS will have energy-saving sensors that turn off when a space is not occupied and, on average, use 2 watts for cooling and 40 watts for heating. In comparison, conventional space heaters operate at up to 1,500 watts. The foot warmers use energy-saving halogen bulbs operating at 20 watts on average over the course of a typical winter day– far from their maximum power of 160 watts. To top it off, the PCS operates on an easily rechargeable lithium ferrous phosphate battery.
$62 Million in Annual Savings
CBE estimates that the new tools will be able to cut natural gas use by 39 percent and electricity use by 30 percent for heating, ventilation and air conditioning in typical California commercial office spaces. The researchers project that, altogether, the new system could save up to $62 million a year in energy costs in the state, while eliminating 247,000 tons of carbon dioxide equivalent emissions.
Arens said the researchers are keen to incorporate computer science and other innovations. These can help the building sector to take better advantage of the rapid pace of technological advances in heating, ventilation, and air conditioning (HVAC), and also to optimize energy performance when controls are integrated with the new occupant-based technologies.
Academic and Industry Collaborators
Working with CBE on the project is UC Berkeley’s David Culler, co-principal investigator and professor of Electrical Engineering and Computer Science; the campus-based California Institute for Energy and Environment (News - Alert); and Taylor Engineering, a private firm specializing in design of energy efficient building systems. The campus’s Operational Excellence Energy Management Program will support the team’s research.
The work also is supported by a consortium of 40 industry members, including t Pacific Gas & Electric Co.; and the architectural and engineering firms HOK, LPA, and Perkins + Will, which plan to engage in field installations and other related research initiatives.
The research team is also assembling about 100 prototypes of their specially equipped mesh chairs, with built-in heating and cooling, for installation in several demonstration studies.
Edited by Alisen Downey