Energy Efficiency -
Planning an Energy Smart School

Talk with district administrators about their energy-smart buildings. The U.S. Department of Energy and U.S. Environmental Protection Agency operate the ENERGYSTAR Label for Buildings program. Using an analysis tool, schools (and other buildings) are rated from 1 to 100. Schools rating 75 and higher can qualify for the ENERGYSTAR Label. Find an ENERGYSTAR-labeled school in your area and talk with them about their energy-saving initiatives.

(An added bonus — Those schools qualifying for the label can receive a metal, wall-mounted plaque that tells your community that your school is smart about energy — and that you're using taxpayer dollars efficiently!)

Here are some steps to help you in your decision-making process (some apply to retrofitting, others apply to both new and existing buildings):

   Perform an Energy Audit
   Compare Your Building to Others
   Software Tools to Evaluate Your Building's Performance
   Explore Financing Options
   Choose the Most Effective Measures
   Other Considerations for Your Assessment

You and an energy auditor should examine your pertinent data and utility bills. Data to be collected includes:

1. Type of school
2. Total square footage
3. Hours of occupancy
4. Number of occupants
5. Building age and principal construction type
6. Energy system operation and maintenance practices
7. Type of heating, cooling, lighting, and control systems
8. Numbers and types of energy-intensive equipment
9. Energy usage data for surrounding schools (for comparison) (minimum one year of data)
10. At least one year of utility bills — rates can fluctuate seasonally
    
    

An on-site energy audit can identify specific energy- and cost-saving measures that could be implemented in your school building. An energy audit will produce a report that typically includes the following:

1. A comprehensive analysis of energy costs
2. Specific recommendations on energy- and cost-saving renovations
3. Recommendations to reduce electrical or fuel demand costs
4. Estimated costs of energy efficiency measures
5. Projected annual energy and cost savings
6. Available financial or other support from the utility (or others)
7. Recommendations for further analysis

A professional energy auditor is an important resource. When choosing an auditor, consider these important factors:

1. Knowledge of costs for energy renovations
2. Skill at evaluating schools specifically
3. Skill at performing energy surveys, and knowledge of your existing and potential energy systems and technology
4. Experience with evaluation of benefits
5. Knowledge of life cycle costing methods

Qualified energy auditors can be found by checking local business directories, consulting local utilities and government energy agencies, and by consulting architecture and engineering firms.Your state energy office and local utilities are valuable resources of information about energy audit procedures in your area.

To determine your building's current performance level (or your proposed building's performance), it may be useful to compare it to other buildings in your area.

To compare energy costs, you can look at annual expenditures in total or by fuel type on a square-footage or per-student basis.

To compare energy consumption, compare your energy use intensity (EUI) with that of other local schools and those across the United States. If most of the schools in your area have lower EUIs than yours, it may be an indication that energy saving opportunities exist in your school. To calculate your school's EUI, use the following formula:

The federal government has several tools to assist in your comparison.

The U.S. Department of Energy's Oak Ridge National Laboratory has a school benchmarking tool that allows you to compare your school's EUI against others in your DOE region.

DOE and the U.S. Environmental Protection Agency's ENERGY STAR Label for Buildings program has tools for benchmarking your school nationally. If your score is in the top 25 percentile nationally, you may even be eligible for the ENERGY STAR Label for Buildings.

DOE offers two software packages that evaluate your school's energy performance.

The Facility Energy Decision System (FEDS) assesses and analyzes energy efficiency of single or multiple buildings. It is especially useful in determining which schools in your district should be the first to be retrofitted. FEDS uses a database of typical costs to determine lifecycle costing.

Once it is determined that a school has energy saving opportunities, an engineer or architect may use a simulation package to verify performance of the retrofit. The software program DOE-2 can be used to predict energy consumption after the retrofit.

DOE also offers other analysis tools that may be of interest to you.

Even in this early stage, you should look at cost and financing issues, develop some rough cost estimates, and consider your financing options.

Perform a cost/benefit analysis (PDF 27 KB) Download Acrobat Reader. on each possible energy-saving measure to identify those with the best investment potential.

The choice of a financing mechanism from among the variety of public and private sources will affect which improvements can be made.

Five general financing mechanisms, which can be used in combination, are available for investing in energy efficiency: internal funds, debt financing, lease or lease-purchase agreements, energy performance contracts, and utility incentives.

Once you've analyzed your current situation and developed a list of possible measures, a skilled energy analyst can help you select the best opportunities for savings. When choosing an analyst, look for the following qualifications:

• Building energy survey skills
• Data collection experience
• Building energy analysis expertise
• Communication and computer skills

Equipment Replacement

HVAC equipment at or near the end of its useful life could be replaced with more efficient equipment. For example, most older boilers seldom operate at their rated output. Replacing old boilers with smaller, high-efficiency, modular (multiple) boilers can boost seasonal efficiencies by 5% to 10% or more.

Replacing existing electric resistance heating systems with heat pumps or other systems that are more efficient or use lower-cost fuel can also provide substantial energy savings.

Replacing existing cooling equipment with higher-efficiency equipment provides attractive paybacks. High-efficiency, direct-expansion cooling units (referred to as packaged or split systems) are twice as efficient as older systems with standard efficiencies.

The energy efficiency ratio (EER) of the new system divided by that of the old indicates how much more efficient the new system is. Higher-efficiency chillers significantly outperform older systems and meet current U.S. (non-CFC) refrigerant requirements. Compare chiller coefficients of performance (COPs) to indicate potential energy efficiency gains.

During replacement or conversion of a chiller, consider upgrades to energy systems that cool or affect cooling load. Installing efficient chiller systems, rather than simply converting them or replacing them with units that meet minimum efficiency criteria, can be an important energy-saving upgrade.

Reducing cooling loads enables you to "downsize" your chiller, which will save energy and cost less. Cooling loads can be reduced through high-efficiency lighting upgrades, building shell improvements, or other measures.

The savings associated with purchasing a smaller chiller allows a building owner to buy a more efficient model. Savings from lighting or other upgrades also offset the cost of a more efficient replacement chiller. Another way to reduce new chiller size and cost is to install new, more efficient HVAC auxiliaries (e.g., evaporative cooling towers, coils, variable-speed drives). Alternatively, look for ways to improve the efficiency and operation of auxiliary chiller components and distribution systems.

Equipment Improvements

As an alternative to replacing existing equipment, numerous retrofit options exist, including operation and maintenance measures. For example, capturing rejected heat is a relatively new retrofit approach that saves energy and has a rapid payback. In fossil-fired heating systems, heat can be recaptured by condensing exhaust gases (this captures most of the heat typically exhausted through the flue). Heat recovery from building exhaust air streams is also becoming very popular. The recovery is accomplished through heat exchanger coils, heat wheels, and air-to-air heat pipes. In steam systems, the capture of condensate return is essential for efficient operation.

Operation and Maintenance Opportunities

Frequently, inexpensive opportunities exist from better building operations and maintenance (O&M) activities that yield tremendous energy savings and increased comfort. Quick fixes and building tune-ups fall into this category. Consider O&M solutions and capital improvements.

Integrating Measures

Another approach to energy efficiency is considering load-, system-, and plant-level savings opportunities in strict progression. Proponents of this approach cite the multiplier effect that can be achieved if plant-level equipment is significantly downsized as a result of reduced energy requirements at the load and systems levels.

For example, the size of plant replacement chillers can be significantly downsized if the building's thermal load and system inefficiencies are reduced. (In large schools, more energy-efficient, computer-driven food preparation equipment lowers the cooling load and simultaneously reduces cooling requirements.) With limited capital, however, this approach will not necessarily achieve the greatest energy and cost savings. Always consider the energy use impacts and interaction of the building, its equipment, and the occupants.

For example, analyze the potential interactions between lighting improvements and mechanical equipment. Lighting improvements generally lower generated heat in the building. As a result, cooling energy will decrease and heating energy will increase. Since overall cost benefits are highly dependent on heating and cooling system efficiencies and fuel costs, dramatic cost benefits might occur in one building, while another building with high heating costs might achieve only half of the predicted savings.

Another example is the interaction between mechanical system upgrades and improvements to the building shell. In some cases, upgrading the heating or cooling system while simultaneously adding insulation can dramatically decrease the savings that might have otherwise been gained from the addition of the insulation alone. In this scenario, either measure alone could be cost-effective, but the second measure would deliver less benefit per dollar of investment. Both examples illustrate the value of examining overall building energy impacts.

New Construction/Major Rehabilitation

New construction (e.g., additions) and building rehabilitation are particularly opportune times to incorporate energy efficiency improvements and can significantly reduce the cost of improvements (as compared to the cost of later retrofits). As a result, improvements that may not be cost-effective in a retrofit situation become viable.

Environmental Incentives

Several environmental incentives may induce building owners or occupants to install new equipment, more efficient equipment, or both. For example, hazardous PCBs present in older fluorescent lighting ballasts and the emissions from fossil-fired heating systems or electric generating stations are increasingly regulated and monitored. In many cases, the cost of a failure or the cost of compliance will begin to equal a substantial part of the cost to replace the system.

The mandated halt to production of ozone-destroying CFCs forces many building owners to consider compliance cost trade-offs. A large portion of the chiller stock in the nation depends on CFCs as refrigerants, but CFCs have become increasingly difficult and expensive to obtain since January 1, 1996. Unless an inexpensive CFC-replacement refrigerant can be developed and put on the market, chiller conversion or replacement with models that use some other non-CFC fluid are the most desirable alternatives.

• ASE Green Schools Program
• National Energy Education Project
• National Energy Foundation
  

Pasco County Schools: Benefiting from
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College Station Independent School District: Texas District Takes Advantage of Rebuild America Network (PDF 342 KB)
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