At the Center for the Built Environment, at the University of California at Berkeley, researchers have been working out ways to make people comfortable using tiny amounts of energy. Their developments build on studies of many human subjects in carefully controlled laboratory environments to determine the ranges of environmental variables which most people would find comfortable. These studies have made the prime researchers, Professors Ed Arens and Hui Zhang, influential in defining the best accepted standard of thermal comfort, known as ASHRAE 55.
Their work is a little bit like Back to the Future. Rather than ever more use of energy-intensive refrigerated air, Arens and Zhang have focused on factors like the effect of air movement. Not surprisingly, a bit of air movement can make a big difference in most people's perceptions of comfort when temperatures are rising. One of the tools used is a tiny, variable-speed fan which can be controlled by the user through her computer. Cleverly, the controlling software also communicates the level at which users set their fans to a central data collection point, which could be accessed by the master building control system.
Ironically, one of the commonest summer-time complaints heard in North American office buildings is that occupants are too cold. It's not surprising, when you consider that to maintain fixed temperature set-points year round, buildings blow massive quantities of refrigerated air into the space as temperatures outside heat up. Somebody is bound to be right under one of those jets of air and end up freezing cold. To deal with this, the thermal comfort studies indicated that the warming of people's feet and hands was the most efficient way of producing comfort. Small devices were developed to warm the top of the feet radiantly, again using tiny amounts of power and controlled by the occupants through their computers. Of course these techniques work in winter-time conditions as well.
There are several ramifications of this work that have powerful potential to reduce the energy we use heating and cooling buildings, and also in improving the overall comfort of the occupants of those buildings. The first is that just giving people some control over their own environments improves their satisfaction. No two people are alike in their thermal preferences, and all too often people with very different needs sit near each other.
Second, with the communication feature, the building itself can adapt to its occupants' desires. If the control system sees all the personal fans in a zone turned up, it can bump down the temperature in that zone slightly. This way the people in the building actually become the temperature sensors. And in fact, they are the sensors that really matter.
Third, in cooling season, the building could adjust so more people use their cooling fans and fewer use their foot warmers. This would automatically reduce the cooling energy used in summer by letting the building warm to the top of the comfort range. If the goal is to minimize peak demand, an effective strategy is to pre-cool the building in the morning and allow it to warm up over the course of the day. With this strategy, the building could use both heating and cooling devices, monitoring the personal control settings so as not to overcool in the morning, or overheat in afternoon.
Finally, and importantly, these personal control devices can be deployed quickly and inexpensively in existing buildings without requiring major renovations or upgrades. From the societal perspective, this allows a major reduction of energy use quickly and with minimal investments. There would even be a few jobs created making and installing the controls and getting them integrated with the existing building control systems.
Now for the bad news:
Most of this work, and much else, has been supported by the Public Interest Energy Research program at the California Energy Commission. The program was wisely set up to fund research “not adequately provided by private or regulated (i.e., energy utilities) markets.” The California legislature didn't vote to re-authorize this program, so its funding, which was $62 million annually, will stop being collected at the end of 2011. When the existing funds are spent, and the existing projects finish, there will be no more, and research programs like the Center for the Built Environment will wither.
$62 million sounds like a lot of money every year, and it is, giving the program a significant impact and world-wide recognition. There's even word that China intends to do something similar. Looked at another way, it's less than $2 a year for each Californian. Surely the Golden State can afford the price of a cup of coffee for its citizens to keep a world-class research program going. Governor Jerry Brown is trying to find a way to keep the program funded. If you agree, it would be worthwhile to contact the state's legislators and urge them to do so as well.