Saturday, January 17, 2009

Thermal Inflation and Thermal Deflation
December 31, 2008

In 1980-1981 I pointed out that the ASHRAE notion of thermal comfort had undergone significant thermal inflation. I also presented a paper that indicated that there were individual differences in people’s environmental temperature requirements, and that these needs varied at least in part with personality. Since then, the Reagan Administration has become history along with the energy crisis and the Emergency Building Temperature Restrictions that they terminated. Now we find ourselves as a world society at the beginning of an energy and environmental crisis. It may be that this is caused by world demand being close to world supply. It may be that this is caused by the restrictions on burning fossil fuels if we are to avoid destructive global warming. It may be for other reasons. Whatever the cause, we know that we must take action. ASHRAE and many other entities are doing so. The issue is how much time we have to get results, and how fast our society can move.

This involves the adoption of new technologies and new ways of living and working. Adoption typically takes at least decades. Firefighters took fifty to sixty years to reach 50% adoption of self-contained breathing apparatuses (SCBA) that protect them from death by inhalation. Significant adoption of efficient energy design and technology, “clean” technology, and green technology began only about thirty years ago, and became a political issue in a way that SCBA never did. With this and James Hansen’s statement in his study that we have less than ten years to gain control of carbon entering the atmosphere, it would seem to be likely that adoption will not happen fast enough. One hopes that there is more slack in environmental systems than Hansen suggests, but even if there is, the financial, social and political investment will be staggering to achieve the requisite goals in twenty to thirty years. Given that our society is currently structured around consuming energy, it will require very close to 100% compliance. A question to think about is whether this can be achieved without enforcement efforts that would be unacceptable to participants in a democratic society.

There are two directions that this entry can now go. One is an exploration of rapidly achieving high levels of adoption. I am one of many who is working on this. Congressman Ed Markey, chair of the House Select Committee on Global Warming has stated that establishing the future system of auctioning carbon will have the same high impact as did the system for auctioning electricity. Surely this will help a great deal. But will it be enough? If not, and if our society does not foolishly deny the science, then we will be in for some hard choices. Every ton of carbon into the atmosphere will be important. We will have to consider setting back our thermostats once again.

Can we do it better this time than last time? I think so. We need to start right now to investigate what temperatures are acceptable to people. Not “comfortable,” but “acceptable” and we need to start looking now toward shifting building standards toward acceptability rather than comfort.

What is acceptability? A better term would be “acceptable discomfort.” I suggest that it is a temperature that makes occupants uncomfortable, but uncomfortable to the degree that most of them do not complain, do not shiver, do not leave the occupied space. During the winter the published thermal comfort standard would diagram the resulting acceptable discomfort zone for people wearing sweaters above the waist and pants or equivalent below the waist. The published thermal comfort standard for the summer would diagram the resulting acceptable discomfort zone for people wearing very light clothing and performing sedentary tasks.

In addition to providing immediate reductions in energy consumption, implementing a standard of acceptable discomfort happens to further another agenda, thermal deflation, the adaptation of people in our society to lower temperatures in winter, higher temperatures in summer. For thirty years my wife and I have been experimenting with adaptation to lower winter temperatures. We have chosen to live in quite cool but not overly cold environments. Whatever level of clothing we are wearing, we seek to be “acceptably uncomfortable.” At first we were challenged by living at 65-70. Sixty was painful. By now this has all changed. We have turned on the heat to reduce risk of freezing our water pipes, and to raise the temperature to 55 for my wife. I have yet to turn on the heat where I work in my Boston house. I live at 50, and find 55 to be quite warm. There were two goals in this exploration. One was to demonstrate that it is possible to live in a cellar with no heat, should that ever become necessary. The other was to demonstrate that it is possible to live productively at 55 with considerable clothing, but not so considerable as to significantly restrict motion and activity. We find that we need to fill our tank of oil just twice a year. We have called off the regular deliveries of oil, since their coming out to our house so often was a waste of time and energy for the oil company.

Setting aside my theories and experiments, it is apparent that there is slack in our human systems enabling further quick reductions in heating and cooling without reductions in productivity or acceptability. ASHRAE needs to start soon to foster research to document this area of human requirements. If more purely technical means do not achieve the required goals for insertion of carbon into the atmosphere, then we may need to know what people will require for thermal regimes without significant complaint or anger.

No comments: