ENERGY EFFICIENCY IN COMMERCIAL DEMAND-SIDE MANAGEMENT

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Energy efficiency can enhance human health by reducing greenhouse gas emissions, improving indoor and outdoor air quality, and decreasing acid rain. The energy needed to run commercial and industrial buildings in the United States produces 19 percent of U.S. carbon dioxide emissions, 12 percent of nitrogen oxides, and 25 percent of sulfur dioxide, at a cost of $110 billion a year.

The commercial sector is in need of cost effective solutions to address the rising cost of energy and the health implications of energy use.  Once a facility has developed an energy baseline by tracking and measuring its energy use, it can begin to zero in on key areas of inefficiency and review potential energy reduction strategies with an eye for what will work given the financial resources of the organization. Improving the efficiency of energy end uses reduces both energy cost and greenhouse gas emissions – and is often called ‘demand-side management’.  A robust energy efficiency program is the foundation for a business to take its next step towards a cleaner energy portfolio – and is often called ‘supply-side management’.  Displacing the use of conventional energy with clean, renewable energy reduces GHG emissions and contributes to softening price volatility associated with oil, natural gas, coal and electricity generated from these fuels. Learn more about supply-side management.

Demand-Side Management

Demand-side management is a facilities management approach that involves ways to reduce the need for energy.  The key in demand-side management is conservation through system-wide energy conservation programs. These types of programs identify cost-effective procedures that reduce energy consumption and develop systematic programs of energy system efficiency improvements. Commercial facilities examine and analyze energy use to determine where it could be possible to cut back.

There are several key areas a commercial facility can target when looking for energy efficiencies. The following areas are the energy use categories laid out by EnergyStar and provide a useful framework for assessing opportunities for energy reduction:

Retrocommissioning

Commissioning involves ensuring that mechanical systems are designed, installed, functionally tested, and capable of being operated and maintained according to the hospital’s operational needs. Commissioning usually takes place when the building goes into service. Retrocommissioning involves the same process of reviewing systems alignment and optimization, but takes place at a later point in the building’s lifecycle—and can recalibrate systems to function more efficiently and effectively—reducing energy and improving operations.

Lighting

Lighting consumes close to 35 percent of the electricity used in commercial buildings in the United States and affects other building systems through its electrical requirements and the waste heat that it produces. Upgrading lighting systems with efficient light sources, fixtures, and controls can reduce lighting energy use, improve the visual environment, and affect the sizing of HVAC and electrical systems. Looking at the intensity of lighting in different areas—i.e. what levels of illuminance are appropriate for a clinical area vs. a supply closet—may also identify opportunities for modifications and greater efficiencies.

Supplemental Load Reduction

Supplemental load sources are secondary load contributors to energy consumption in buildings—typically people, computers, lights, and the building itself. These loads can adversely affect heating, cooling, and electric loads. However, the effect of supplemental loads can be controlled and reduced through strategic planning and implementing energy-efficient upgrades. With careful analysis of these sources and their interactions with HVAC systems, equipment size and upgrade costs can be reduced. These upgrades can increase HVAC energy savings and reduce wasted energy.The best ways to reduce supplemental loads include:

  • Reducing equipment energy use
  • Upgrading the building envelope by improving insulation, fenestration, and roofing

Air Distribution Systems

On average, the fans that move conditioned air through healthcare institutions account for about 8 percent of the total energy consumed by these buildings, so reductions in fan consumption can result in significant energy savings. A U.S. Environmental Protection Agency (EPA) study found that almost 60 percent of building fan systems were oversized by at least 10 percent, with an average oversizing of 60 percent. “Rightsizing” a fan system, or better matching fan capacity to the requirements of the load, is an excellent way to save energy in air distribution systems. There are also opportunities for energy-saving improvements to the air distribution system in four other categories:

  • Adjusting ventilation to conform with code requirements or occupant needs,
  • Implementing energy-saving controls,
  • Taking advantage of free cooling where possible, and
  • Optimizing the efficiency of distribution system components.

Heating and Cooling Upgrades

Heating and cooling systems account for a significant portion of a building’s energy use—typically about a quarter. However, it is possible to lessen this impact in both central and unitary systems by increasing their efficiency. Cooling systems generally have higher space-conditioning capacities than heating systems because waste heat from people, lighting, and office equipment supplies a large portion of a building’s heating requirement. Although their higher capacities often translate into more opportunities for savings from cooling systems, significant savings can still be had from heating systems.Many existing systems are oversized to begin with, so it may now be possible to justify replacing the current system with a properly sized one—or retrofitting it to operate more efficiently. When replacing system components, it is extremely important to size the equipment properly to meet current loads. Besides saving energy, proper sizing will likely reduce noise, lower first costs for equipment, and optimize equipment operation, which in turn reduces maintenance costs and extends equipment lifetime.

**The material above comes directly from Energy Star’s Building Upgrade Manual

A Staged Approach

Energy Star recommends a staged approach to energy efficiency, meaning that an organization would want to look at the efficiency mechanism categories above in sequential order. Energy Star points to the fact that many of these strategies build upon each other and can increase efficiencies in later strategies if the early strategies are completed first.

Purchase of Energy Efficient Products & Equipment

The US Department of Energy provides several energy efficiency fact sheets on buying energy efficient equipment including:

 


Resources

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