Every year, college classrooms and other educational facilities waste millions of dollars in energy costs. Heat seeps out of under-insulated walls. Outdated energy control systems keep classrooms too hot or too cold in the winter. Lights stay on in empty rooms, needlessly drawing and wasting energy.
Systems ranging from temperature control and thermal insulation to ventilation, indoor air quality, and lighting have the most influence on energy usage in an educational facility. Get them wrong and you could be squandering not only your own energy dollars but the nation's energy future as well. In fact, "Unlocking Energy Efficiency in the U.S. Economy," a recent McKinsey & Company study, noted that a reduction of just 29 percent of current energy use in buildings via retrofits could save the country an estimated $290 billion in energy costs as well as eliminate 360 million tons of GHG emissions.
To put these environmental savings into perspective, a reduction of 360 million tons of GHG gases is the equivalent of removing 73.1 million energy sipping hybrid-electric Toyota Prius vehicles from the road. What this means for our energy future is clear?in order to have a positive financial and environmental impact moving forward, making our buildings energy efficient is the key to enabling a low energy future.
Fixes, small and big, can pay immediate dividends and keep paying off for years to come. Here are the top ten energy wasters at higher education institutions and what officials can do about them.
An outdated energy management system is like a brain that doesn't quite compute. You're chilled or hot in the wrong places and the wrong times. An energy management system using direct digital controls improves time of day scheduling, ventilation control, temperature reset, and cooling/heating plant optimization. Depending upon the present configuration and application, the energy cost savings could be significant.
Operating without a central plant control is like a body without a central nervous system. You don't know what you're fingers and toes are doing, or in this case, your air conditioning and boilers. Mechanical system capacity control and management is a key strategy in achieving energy efficiency. Correctly staging the operation of the central plant equipment for cooling and heating is a great way to improve energy efficiency. Most facility managers monitor standard operating points and stage equipment on or off based on set points. However, the actual performance of individual equipment is seldom analyzed or monitored. Monitoring the actual performance of equipment at various levels of capacity and matching usage to need will greatly enhance the overall energy performance of a central plant.
Routine preventative maintenance of heat exchanger surfaces (boiler cleaning and water treatment, cooling tower cleaning, chiller preventative maintenance, etc.) is critical and should not be neglected. To help ensure these maintenance issues are not forgotten, many facilities are using computer programs to set up scheduled reminders for specific maintenance tasks.
Domestic hot water systems are prime candidates for efficiency improvements. Applying temperature regulation and thermal storage techniques and making use of new technology such as on-demand hot water heating systems and heat recovery systems will reduce the energy cost of producing and delivering hot water.
The operation of most schools creates a logical and economic need for energy-efficient lighting systems. Small improvements in energy efficiency over long periods of operation balance the economic investment of installing and maintaining energy-efficient lighting systems. Recent improvements in lighting technology include load management options such as daylight harvesting, occupancy control, and automatic and manual dimming.
Universities often use pumps to transport chilled or condenser water. Improvements in system efficiency can reduce pumping system energy by 50 percent or more.
A good energy solutions firm can help you make your pumping systems more energy efficient by considering strategies such as:
- Rightsizing - Replacing oversized impellers, pumps, and motors with right sized equipment;
- Variable Flow - Replacing constant volume systems with variable flow systems that adjust the speed of the pump depending on the performance required, reduces the energy used;
- System Conversions - Converting single-loop configurations to primary-secondary loop configurations for more efficient operation.
Improvements to a facility's heating plant, either steam or hot water, can result in energy costs savings. The combustion efficiency of older boilers is generally between 65 and 75 percent, and poorly maintained inefficient boilers can have efficiencies as low as 40 to 60 percent.
The best opportunities for energy savings come with replacing an old or inefficient boiler with a more efficient boiler system. Energy-efficient boilers have increased heating surface areas and improved controls for fuel and airflow over the range of load conditions. Consult an expert to help you determine whether you should replace a boiler system or upgrade key components.
Some educational facilities employ steam as a major energy source for heating systems. Old steam systems are very large energy users and can be relatively inefficient when used for building heating. Considering the consistently high temperatures of low, medium, and high pressure steam, distribution losses are high and stack temperatures are elevated. Modifications to steam systems represent low cost, high savings activities such as trap maintenance/replacement, pipe insulation, flash steam recovery, stack economizers, and other measures that reduce the amount of heat loss.
Schools are huge consumers of water. Water and sewer costs are increasing in many areas and water reduction can be a viable conservation measure. You can decrease your water cost through the use of low-flow faucets, toilets, and urinals and the application of sensor based technology.
When standardized maintenance and energy management procedures fail to fix chronic building problems, re-commissioning provides a systematic approach for discovering and solving them. Retro-commissioning entails the examination of actual building equipment systems' operation and maintenance procedures for comparison to intended or design operation and maintenance procedures.
In order to minimize energy loss and maximize cost savings, facility managers should evaluate their sites in these critical areas to identify the highest priority retrofitting improvements. By conducting a thorough audit of the site's systems, and then implementing appropriate changes, they can save millions of dollars and also reduce their facility's carbon footprint.
David Leathers is senior vice president, building service and energy solutions, with Limbach Inc.