CBE Director Ed Arens, came to UC Berkeley in 1980 and soon founded the Building Science Group. In this interview he reflects on major milestones in the formation of CBE’s organization and contributions.
Q: How did you first become interested in the research and work you are doing here?
Ed Arens: This really goes back, before anyone in the U.S. really talked about energy or building science. It was when I was in architecture school in 1963, and I read a book called Design with Climate by Victor Olgyay. It was before houses had air conditioning, and it attempted to systematize passive cooling design. Olgyay’s line of thought about climate’s fundamental impact on design was soon to be on its way out. I was taken by the aesthetic potential of the ideas presented in the book, and it made me dissatisfied with my architectural education. I also was influenced by images of the work of Esherick and Halprin at Sea Ranch. I went to forestry school at Yale (now the Yale School of Forestry and Environmental Studies), where they had a micro-meteorology program that I became immersed in. I focused on climate and design, and did a concurrent City Planning degree, thinking the micro-meteorology more appropriate at urban scale. Then I went to Edinburgh, where they had a scientific program in city planning and architecture, called building science. There I did my Ph.D. on building energy and human comfort — still the same topics as now, and that was 1972! Those topics have remained fruitful, so I’m still at it.
Q: Tell us how the Center for the Built Environment (CBE) got its start.
EA: Prior to the start of CBE, our ‘Building Science Group’ was formed in 1984 when we hired new young faculty — Gail Brager, Fred Bauman, and Cris Benton. We were soon working on a big ASHRAE field study of thermal comfort in 20 buildings. The advanced approach used in that study prompted other studies worldwide, and became the basis for the very influential ‘adaptive comfort model’ developed by Gail and Richard deDear, and an ASHRAE global database that we still reference today (and continue to expand). That project also led to studies on ‘task-ambient’ conditioning and underfloor air distribution (UFAD), starting back in the late 1980s.
At that time, we were still a small group of faculty and grad students supported by relatively small energy-related grants. We were approached around 1995 by the National Science Foundation (NSF) to be involved in an industry-university collaboration program. To start as an NSF Center, we had to recruit ten partners — this was hard work during a period of downturn in the building industry! On the other hand, principals were looking for competitive advantages. From that, CBE started.
Although NSF funding ended after about ten years, CBE carried on and increased its membership using the NSF model. I am eternally grateful to them and our founding members, including Arup and the U.S. General Services Administration who are still partners today.
Q: How have you seen CBE evolve in the past 20 years?
EA: In the early days, our biggest partners included UFAD companies. We were interested in the technology because of its potential to directly supply personal comfort devices with fresh air, as well as possible energy efficiency. To date, UFAD hasn’t gained traction with personal comfort systems, but has been very interesting in its own right. CBE helped develop comprehensive lab and field testing, computer modeling, and cost analysis. Fred Bauman really became the expert in this. CBE helped get that whole industry off the ground in the U.S. We have written codes and standards, ASHRAE design guides, and we are still on committees for room air distribution to this day.
Now we’ve moved on to radiant systems, largely because of the energy savings implications, but there are comfort opportunities as well. Modern radiant systems were developed for heating in Europe, but in the U.S. we need to figure out how to also incorporate radiant cooling. There is a link to personal comfort systems here because radiant systems, though incredibly energy efficient, can’t respond quickly to individual differences and needs. Personal comfort systems, including ceiling fans, are a great match for radiant because they give you an immediate response. I think such combinations are the future.
Q: What are some of your current challenges, and directions that most excite you?
EA: We have funding from the ARPA-E DELTA Program, which supports furniture-based and wearable personal comfort systems. Hui Zhang and I are doing fundamental physiological work to help us find the most efficient ways to heat and cool people. We are also looking at ways to power these devices without cords, and to use them as communicating sensors that enable better control of the whole building. So I am still working on personal comfort systems, making them more personal and sophisticated.
I’m also enthusiastic about our ultrasonic airflow sensing project, which has the goal of measuring air flow and temperature better, both within rooms and in ducts. Air flow presents a fundamental gap in current sensing. If we could measure the speed and temperature of air flows reliably and inexpensively, then we’d have a breakthrough in how we design control buildings and systems. Right now we are totally guessing, without accurate feedback, and designs have to include huge safety factors. We still have about two years left on the project, and we will continue to work on getting an affordable and reliable sensor developed. It’s an important project for me personally, and will impact everyone’s projects around here.
My goal is to influence the world, to influence the industry. Our graduates are all in significant positions and making a difference. It’s been great to see CBE partners out in the forefront, coming up with projects that employ innovative approaches and really push the limits. They are also coming up with the most liveable buildings, as our surveys quantify. I think some of it has been made possible by CBE pushing these ideas relentlessly, and providing the scientific evidence that these things are possible.
Q: Where do you see CBE 20 years from now?
EA: The personal comfort space is still completely wide open. That means buildings will be more integrated with furnishings, ultimately, you could perhaps even include clothing with furnishing. And by doing it this way, two things seem to happen. First, you reduce the responsibility of the building to provide individual comfort, relying on it instead to provide a basic environment that the occupants can tune. Such a building can be highly energy efficient, such as a hydronic radiant building. Second, as personal comfort systems in furnishings and clothing become commodities like cell phones, they’ll become affordable, widespread, robust and reliable. By having them share in the conditioning of the space, we’ll be able to do things more efficiently. I think CBE has to work on creating the industry ecosystem for this, and we are certainly well-positioned to do so. Decentralization and democratization of building controls, occupant centrification in design – those are good things.
Health is another important topic. This has been a difficult problem for researchers to deal with because of the enormous complexity. We’ll focus on design and control issues, perhaps in relation to new or improved sensing opportunities. The airflow sensor might be one of these. We have also done some biotech work in the last few years (such as the DNA sequencing of bacteria in indoor environments), which was really fun. You need chemists, and other people from different disciplines, and there are a lot of opportunities for collaboration. I think we’ll be involved in some capacity.