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Sustainable Design In A Bottom Line World

You may have seen articles highlighting "green" building projects. Many of these buildings push the envelope of efficiency in their use of resources both for the building's construction and ongoing energy needs. Often the owners of these facilities have a vested interested in environmental education. Some are enlightened owners who care deeply about the environment, while others believe their investment in green design will provide a worthwhile return in publicity or occupant satisfaction. But what about owners who are more bottom line driven, either out of choice or necessity? Is there a place for sustainable design in their projects?

Sustainable or "green" design strives to limit the environmental impact of a building, and its components, over the entire life of the building. The energy required to produce and transport building materials is considered as well as the energy required to operate the finished building systems. The environment created within and around the building is also optimized. It is a holistic approach to design that is good for all projects in some way.

All owners benefit from reduced owning and operating costs. The proper balance of initial investment and ongoing costs is usually a goal for each project, whether stated or not. Properly designed mechanical and electrical systems can help the owner achieve this goal.

Mechanical and lighting systems consume the majority of building energy. These systems can be optimized with little initial cost premium. The following design ideas can be incorporated into almost any project:

"Right Size" the mechanical systems. Often, building users request or demand far more power (and air conditioning capacity) than they will actually use. If systems are sized closer to actual needs, they will operate more efficiently. Design ways to increase capacity at a later date without over-sizing systems day one.
Take advantage of any incentive or rebate that may apply. For example, tax credits will soon be available in New York State to help offset investments in energy efficient equipment. Likewise, New Jersey has the SmartStart Building Program that provides rebates through the local utilities. These programs can help offset the higher first costs of more efficient mechanical and electrical systems.
Optimize fans and pumps. Fan and pump energy accounts for 20-50% of the energy used by a typical HVAC system. Fans operate whenever the building is occupied. Use variable speed drives on fans and pumps when possible. Reduce pump energy by increasing fluid temperature differences. Reduce fan energy by using lower supply air design temperatures. This approach also reduces piping and ductwork installed costs.
Make full use of digital building controls. Control feed back from zone equipment such as VAV boxes can be used to adjust air and water temperatures to optimize comfort and energy costs. CO2 sensors can be used to control ventilation based on actual demand. A fully capable control system can also reduce manpower costs.
Use the most efficient light sources and fixtures feasible, design for the lowest reasonable light levels, use light colored, reflective interior finishes and make use of energy saving controls such as occupancy sensors and daylight dimming systems. Lighting control has a double payback in that it reduces air conditioning costs and lighting energy. Don't sacrifice lighting quality to reduce energy. Efficient lighting is not just about watts and foot-candles. It involves applying light where it does the most good. Lighting walls allows for lower light levels throughout a space.

Sustainable design is good for the owner's bottom line and for future generations. It should not be viewed as an afterthought or an additional task and can be practically achieved in some form on every project. Incremental improvements in many buildings will have a greater impact than a few super efficient demonstration buildings.