HVAC Trends: The New HVAC
By Gordon Holness, P.E.
Published in the January 2010 issue of Today's Facility Manager
Today, there is growing recognition of the need to reduce consumption of fossil fuels and to decrease the discharge of greenhouse gases dramatically. With buildings consuming over 40% of global energy used, the new year offers a significant opportunity to contribute to these efforts by increasing the energy efficiency of existing building stock through legislation, technology, and design.
First, these issues have been recognized by the U.S. with initiatives contained in the Energy Independence and Security Act of 2007 to improve the energy efficiency of all new and existing federal buildings. Further support is provided under the American Recovery and Reinvestment Act (ARRA), an incentive program that offers federal funding in exchange for agreement by states and localities to adopt, provide training on, and enforce advanced energy efficiency codes. The agreement is based on a commercial building energy code that meets or exceeds the ANSI/ASHRAE/IESNA Standard 90.1-2007. Europe is aiming at net zero or “nearly net zero” commercial buildings by 2019.
Current legislation being considered in the U.S. House and Senate would further increase the required efficiency for commercial buildings by 30% in 2010 and by 50% by 2016. Tax incentives for existing building retrofits are also being enhanced. Though facility managers (fms) have yet to see the outcome of discussions on carbon taxes and carbon cap and trade, as well as how the White House promise to reduce greenhouse gas emissions by 17% before 2020 will impact energy prices, the likelihood is that costs will increase.
These changes have the potential to impact the HVAC industry radically. The energy efficiency levels being considered will require a different approach to providing a healthy and comfortable environment. HVAC systems with high energy transport efficiency (e.g., water and refrigerants) will take preference over those using low energy transport (e.g., air). This would suggest a greater potential for the use of dedicated outdoor air systems with energy recovery coils and under ventilation demand control.
Greater use of radiant heating and cooling systems is expected. High efficiency “mini split” systems with variable speed fans and compressors for close, sensible, and latent heat control can also be anticipated. Fms can further expect greater use of heat pump systems, including ground source, water source, and geothermal, dependent upon location and climate. While heat pumps with a COP (coefficient of performance) of 2.78 or above have long been considered a renewable energy source in Europe, they have only been given that status in the U.S. recently; acknowledging them as such is another step toward efficiency in 2010.
With increased emphasis on operation and maintenance to keep systems running efficiently, fms should expect to see greater use of packaged or modular equipment with inherent capability for self diagnostics. Such systems can be readily used for the retrofit of existing buildings, a significant feature since 75% to 85% of the buildings that will exist in 2030 are already built.
While each new year brings with it more advanced technology, professionals in the building industry need to be prepared to expand and improve the way they work with each other. What is clear is that fms must approach facility design on an integrated team basis. High energy efficiencies can only be achieved by addressing the building orientation, thermal mass, fenestration, and insulation levels in conjunction with design for daylighting, natural ventilation, lighting systems, and environmental control systems—all working with each other.
The biggest impact, however, will originate with changes to lighting systems where new technologies, like LEDs, are having a dramatic effect not only in reducing electrical loads by as much as 75% but also on cutting building heating and cooling loads. This, together with improvements in building envelope design, will directly lead to reduced total thermal loads and, as a consequence, materially impact HVAC system selection and sizing.
To all of these considerations can be added the development of the SMART Grid along with the application of SMART meters and SMART equipment. This will tie well into the growth of intelligent control systems, wireless technology, and greater use of visual tools to assist in the control and monitoring of building systems.
With speculation about the course legislation will take and the technological advances that lie ahead in the new year, one thing is for certain: Fms must strive to achieve sustainability and energy efficiency in all the facilities they design, build, and operate.
Holness, P.E., Fellow ASHRAE, Life Member, is the 2009-10 president of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (www.ashrae.org) and a consulting engineer, West Palm Beach, FL.
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