Editor's note: Following is Part 1 in a three-part series.
A worldwide scientific consensus has established that potentially catastrophic changes in climate as a result of human contributions to greenhouse-gas emissions are likely within the next century if the current growth in emissions is not reversed. To help meet this challenge, a growing number of cities, states, corporations, and organizations have pledged large reductions in their greenhouse-gas emissions. However, many of these initiatives undertaken with respect to buildings are almost certain to fall far short because they are based on flawed or unrealistic assumptions about building-industry processes and technologies. These shortcomings are the result of a gap in understanding between the unique technical and economic characteristics of the building industry and the development of policy that seeks to drive these energy-efficiency initiatives forward.
The purpose of this series of columns is to try to bridge that gap by outlining new approaches that better merge industry efforts and policy and are directed at resolving the technical and economic issues hindering large-scale improvements in the energy efficiency of buildings. By making public-policy advocates more aware of industry developments and initiatives, it is hoped that we can develop a comprehensive road map to a more sustainable future for the building industry and the utilities that serve it.
Presently, buildings of all types consume about 40 percent of all of the primary energy in the United States. This level of energy use is much higher than what modern technologies require to provide comfort and support occupant activities. The fragmented nature of the buildings industry makes it difficult to adopt new technologies that would vastly improve the energy and environmental performance of buildings. However, the fundamental reason new and more energy-efficient technologies continue to be ignored and the technologies that are applied rarely perform as efficiently as they should is because of a lack of accountability for building energy performance in current building design and operation practices.
The result is that buildings of all types typically consume more than twice the energy required to provide comfort and ensure a quality environment for building occupants. It is estimated that realistically achievable savings from well-designed energy-efficiency improvements in the existing-building stock far outweigh all of the expected growth in new-building energy requirements over the next half-century, even at the most rapid rate of building construction.
Therefore, energy-efficiency improvements in existing buildings could, at a minimum, free sufficient energy to serve all new-building energy requirements without the need for any added sources of power generation or fuel through most of this century. It is clear that changes in industry practices and technologies, along with encouraging and compatible public policy, can reverse the current upward trend in building-related greenhouse-gas emissions in this decisive near term.
On the energy-supply side, the scientific community believes that by the middle to the end of the century, low-carbon and environmentally compatible forms of energy for buildings that are safe, reliable, and plentiful can be developed from a variety of options currently being researched, developed, and tested. Then, the human contribution to greenhouse-gas emissions from utilities that serve the building sector can be reduced significantly. However, these new low-carbon electric and fuel sources will be more costly than electric and thermal energy sources currently being used in building operations. Without improvements in building efficiency, the large costs associated with switching to these newer sources of energy could be a significant burden and dampen economic activity.
To meet the challenge for an immediate reduction in greenhouse-gas emissions while ensuring long-term economic well-being and stability, it is recommended that a moratorium on the development and construction of all new greenhouse-gas-emitting power and fuel sources for buildings be initiated. Concurrently, the buildings-industry, utilities, regulators, and policy advocates must work together to transition toward a significantly more efficient and sustainable building stock on an unprecedented scale while cleaner sources of energy for building systems are developed.
Beyond helping to reverse the present trend in greenhouse-gas emissions and deferring short-term capital investments, focusing on an energy-efficient and sustainable building stock will help reduce the costs associated with more expensive low-emission sources as they become available and ensure that this transition does not diminish our competitive advantage or our standard of living.
Because energy costs are a relatively small factor in the economics of virtually all building types, there is little emphasis on building energy performance. Building owners, designers, contractors, or operators seldom have a good understanding of the energy-performance aspects of buildings. This lack of understanding by key decision makers leads to a lack of energy-performance focus in the design, construction, and day-to-day operations of buildings.
Because energy performance largely is missing in building design and operation, the actual energy performance of buildings varies widely when compared with projected performance. This also explains why so many energy-performance upgrades fail to meet expectations and why, as a result, building owners are reluctant to make investments in energy-performance improvements at all.
HPAC Engineering's fifth annual Engineering Green Buildings (EGB) Conference and Expo will be held Oct. 21 and 22, co-located with the Commissioning Green Buildings Conference and Expo at Mandalay Bay Resort and Casino in Las Vegas. To register for EGB 2008, visit www.egbconference.com.
A member of HPAC Engineering's Editorial Advisory Board and principal of The Hartman Co., Thomas Hartman, PE, is an internationally recognized expert in advanced high-performance building-operation strategies. Among his recent innovations are the Equal Marginal Performance Principle and the development of demand-based control, which together offer an effective method to optimally configure and operate complex HVAC systems. He has lectured on advanced-technology topics at seminars around the world.
Read more Engineering Green Buildings columns.