Reducing energy use in buildings has long been the target of green contractors and owners alike. The U.S. Dept. of Energy reports that buildings account for 40% of U.S. energy consumption and building owners spend $40 billion annually on energy. Despite this expenditure, building occupants are often uncomfortable in their work spaces.
Now a study by McGraw Hill Construction (MHC) suggests that high-performance building system technologies already on the market can offer substantial savings in energy use over traditional systems. Working in partnership with Siemens Building Technologies, MHC surveyed practicing engineers and contractors and delved deeper into 10 energy-efficiency technologies to understand those with the most market success.
The Level of Use
The data show that 63% to 71% of engineers and contractors who responded either have a working knowledge of high-performance technologies or have specified and installed six out of 10 of the systems included in the survey. For the newer or more specialized systems, such as chilled beams and cogeneration, more than 40% of firms still reported at least a working knowledge of them, enough to generate sufficient client interest. This suggests that the industry knows about these technologies but the systems are not in wide-scale use, so other factors must play a role.
By far the greatest obstacle to their use is concern about cost. The study says that a building owner's interest and capabilities are also critical factors. Those concerns are supported by in-depth interviews conducted separately with engineers who use many of the systems. Most report the need to consider whether owners have the in-house expertise to operate and maintain the systems. Engineers must also weigh an owner's capacity to handle the risk of new technology.
These findings suggest that more intensive education of building owners and their staffs is essential to take full advantage of the technologies. The main factor driving most engineers and contractors to employ new technologies is their ability to deliver the desired results on specific projects. For example, the study reveals that under-floor air distribution systems can be used effectively in large, open floor plans. Such considerations should drive selection of systems rather than concerns that they will challenge owners' capabilities.
The Benefits of Use
The good news is that when engineers and contractors use these technologies, they result in notable energy savings over more traditional systems. For four of the technologies included in the survey—energy recovery, demand-control ventilation, geothermal and automated facades—more than 60% of those who have used them report a median level of energy savings ranging from 11% to 13% compared with traditional systems. For the remainder of the 10 technologies, one-third to one-half of the respondents report energy savings, with the exception of dedicated outdoor air systems, more typically used in combination with other strategies.
These findings clearly demonstrate that current, widely available technologies can help building owners achieve energy-use goals. But there is no single technology, no "silver bullet," that applies to all building types to get the desired results. The range of technologies and the benefits associated with them show that increased use of existing systems can have a strong impact on energy consumption in the built environment.
However, the study also reveals that benefits can be maximized through systems innovation and integration. Few engineers and contractors who work on these technologies report using them separately, especially among experts from the in-depth interviews. They said the effectiveness of existing systems can be increased.