Introductory Energy Evaluation

Transcription

1 Introductory Energy Evaluation Whitefish Township Community School Paradise, Michigan Prepared by: Kevin Cook Delta Green April 27, 2012 Michigan Energy Office Michigan Economic Development Corporation 300 N Washington Square Lansing, MI shiremant@michigan.gov Phone: (517) Fax: (517) Introductory Energy Evaluation 1

2 Table of Contents Executive Summary... 3 Energy Use Analysis... 4 Figure 1 - Energy Use Index (EUI) Benchmark... 5 Figure 1 - Energy Cost Index (ECI) Benchmark... 6 Summary of Energy Conservation Opportunities (ECOs)... 7 Discussion of Energy Conservation Opportunities... 9 No Cost ECO : Adjust Heating Temperature... 9 No Cost ECO : Reduce Plug Loads... 9 ECO # 1 : Occupancy Sensors ECO # 2 : LED Exit Sign Lighting ECO # 3 : Programmable Thermostats ECO # 4 : Compact Fluorescent Lamps (Option # 1) ECO # 5 : Control Beverage Machine Energy Use ECO # 6 : Hot Water Conservation ECO # 7 : High Efficiency Fluorescent Lighting System ECO # 8 : T8 Fluorescent Lighting and Specular Reflector Retrofits ECO # 9 : Induction Lighting (Option # 2) ECO # 10 : LED Fixtures for Outdoor Lighting ECO # 11 : Boiler Reset Controls ECO # 12 : High Efficiency Boiler System ECO # 13 : High Efficiency Tankless Water Heater ECO # 14 : ENERGY STAR Appliances, Computers & Office Equipment ECO # 15 : High Efficiency Heating System ECO # 16 : Roof Insulation Appendix A: Energy Consumption Profiles Whitefish Township School Whitefish Township School Annex Introductory Energy Evaluation 2

3 Executive Summary On March 28, 2012, a site visit to Whitefish Township Community School identified opportunities for reducing energy cost and consumption. At each building, a visual inspection of mechanical equipment, HVAC systems, temperature controls and lighting was performed. Among the major energy conservation opportunities (ECOs), lighting upgrades, programmable thermostats, boiler reset controls, a high efficiency boiler (Annex) and a high efficiency tankless water heater could help lower energy consumption. Some of the listed ECOs like compact fluorescent lamps, LED exit signs, a pre-rinse sprayer in the kitchen, and a beverage machine controller can be implemented by your maintenance staff as low-cost measures. A planning meeting with appropriate personnel is the next step under Rebuild Michigan to discuss the IEE findings Whitefish Township Community School and to assess your options for further pursuit of energy savings. Below is a proposed agenda for this project planning meeting. PROPOSED MEETING AGENDA 1. Review analysis, Energy Conservation Opportunity (ECO) recommendations and current energy profile as outlined in the IEE report. 2. Assess/discuss any current building projects, objectives and goals related to energy efficiency improvement. 3. Optional action steps: Technical Energy Analysis (TEA) Identifies project costs and energy savings to justify a capital investment in a project. TEA guidelines, Consultants Directory, bid template, and project assistance can be provided by BES staff. Two TEA types Comprehensive (CTEA) which addresses all building ECOs, and Limited Component (LCTEA) which focuses on one specific measure or area of energy use (e.g. lighting) Financing Michigan Municipal Bond Authority, federal and state grants, performance contracting, utility incentive programs, Michigan Saves! and other options. In-house projects 4. Formulating your plan: Timeline for completion. Leveraging outside resources e.g. utility, Public Service Commission funded programs and grants. We look forward to discussing the project options available to Whitefish Township Community School identified through your continued participation in the Rebuild Michigan Program. Introductory Energy Evaluation 3

4 Energy Use Analysis The total cost of energy over the past year at the (2) Whitefish Township Community School buildings included in this report was $29,066. Electricity accounted for 35% of the total cost at $10,146. Propane was responsible for 43% at $12,620, and wood chips (main building) accounted for the remaining 22% at $6300. Using monthly utility bills for the past year, the Energy Use Index (EUI) in Btu per square foot per year (Btu/sq.ft./year) was calculated for each building. Figure 1 on the next page graphs the EUI for each building compared to the average EUI for similar school buildings in Michigan (shown in the next column). Energy use in Btu/sq.ft./year for each building is shown as the combined wood chips/propane (yellow bar) and electricity energy use (blue bar). The chart also indicates the ENERGY STAR Target EUI (green graph line) for each building, attainable through energy efficiency improvements. As shown in Figure 1, both buildings have slightly below average energy use compared to similar school buildings. Figure 2 is a graph of the total energy cost per square foot per year ($/sq.ft./year), or Energy Cost Index (ECI), for each building. A comparison with ECIs for similar Michigan school buildings is provided. The ECI can be a valuable tool to provide a good representation of the actual energy cost per square foot to operate each building and can be monitored over time to detect problems and/or trends. As can be seen from Figure 2, both buildings have below average energy cost compared to similar school buildings. The main building is especially lower than average because wood chips are less expensive as an energy source than propane or electricity. NOTE: Appendix A contains individual energy consumption profiles for each building. Introductory Energy Evaluation 4

5 Energy Use Index (Btu/sq.ft./year) Figure 1 - Energy Use Index (EUI) Benchmark 125, ,000 Average EUI for Similar Building 75,000 50,000 ENERGY STAR Target EUI 25,000 0 S S Propane Electricity Name of Building Wood / Propane Electricity Use Total EUI Average EUI for ENERGY STAR (Btu / sq.ft. / yr) (Btu / sq.ft. / yr) (Btu / sq.ft. / yr) Similar Building Target EUI * Whitefish Township School 90,791 16, , ,000 88,000 Whitefish Twp School Annex 61,478 10,929 72,407 76,000 57, ,000 57,000 * Includes 85 tons of w ood $6300 total cost; 1 ton w ood chips = 12.5-million BTUs Introductory Energy Evaluation 5

6 Energy Use Index (Btu/sq.ft./year) Figure 1 - Energy Cost Index (ECI) Benchmark $2.50 $2.00 $1.50 ENERGY STAR Target ECI Average ECI for Similar Building $1.00 $0.50 $0.00 Series3 Propane Series5 Electricity Name of Building Wood / Propane Electricity Cost Total ECI Average ECI for ENERGY STAR ($ / sq.ft. / yr) ($ / sq.ft. / yr) ($ / sq.ft. / yr) Similar Building Target ECI * Whitefish Township School $0.95 $0.57 $1.52 $2.09 $1.64 Whitefish Twp School Annex $1.36 $0.38 $1.74 $1.81 $1.36 $0.00 $0.00 $0.00 $1.81 $1.36 * Includes 85 tons of w ood $6300 total cost; 1 ton w ood chips = 12.5-million BTUs Introductory Energy Evaluation 6

7 Summary of Energy Conservation Opportunities (ECOs) A. No-Cost ECOs Energy Conservation Opportunity (ECO) Applicable Areas ECO Additional Benefits Adjust Heating Temperature Consider a review of current heating temperatures in comparison to recommended levels. Substantial energy savings can often be achieved by adjusting thermostats or energy management systems. Set point can be lowered to 68F in occupied areas and even lower in unoccupied areas. Each degree drop in set-point results in up to 5% energy savings. Reduce Plug Loads Develop a policy to address excessive plug loads from miscellaneous electric equipment brought into the buildings. Plug loads can account for up to 10% of the power use in a school building. Annex B. Low Cost ECOs Energy Conservation Opportunity (ECO) Applicable Areas ECO Additional Benefits 1 Occupancy Sensors Use occupancy sensors to control lighting and exhaust fans. Rooms with irregular use, restrooms, storage areas and offices usually are the best possibilities. 2 LED Exit Sign Lighting Replace incandescent exit signs with LED units. 3 Programmable Thermostats Replace standard thermostats with programmable models. Heating temperatures can be set back during unoccupied building hours automatically. 4 Compact Fluorescent Lamps (Option # 1) Replace 300W incandescent lamps in Gymnasium ceiling fixtures and wall lanterns outside gym entries with appropriate size compact fluorescent lamps. 5 Control Beverage Machine Energy Use Disconnect lamps and ballasts inside beverage machine, or consider installing power controllers activated by occupancy sensors. 6 Hot Water Conservation Replace pre-rinse sprayer (dishwashing area) with a 1.28-gpm sprayer to save at least 60% on water/sewer and water heating costs. Annex (Gymnasium) (Primarily classrooms) (Gymnasium and Entry) (Kitchen) Extend lamp life. Reduce maintenance LED exit signs have 20-year life. Reduce maintenance. Reduce pop machine cooling load; extend equipment life. Water heating system size can often be reduced after implementation. Introductory Energy Evaluation 7

8 C. Moderate Cost ECOs Energy Conservation Opportunity (ECO) Applicable Areas ECO Additional Benefits 7 High Efficiency Fluorescent Lighting System Replace/retrofit standard T12 fluorescent light fixtures with T8 fluorescent fixtures. A minimum savings of 20% on lighting can be achieved. 8 Retrofit Fixtures with T8 Fluorescent Lighting and Specular Reflectors Where lighting levels exceed acceptable ranges, consider retrofitting each 4-lamp fixture with two T8 lamps, electronic ballast and specular reflector. A savings of more than 60% on lighting can be achieved. 9 Induction Lighting (Option # 2) Replace 300W incandescent light fixtures in Gymnasium with 80W induction surface-mount canopy fixtures. 10 LED Fixtures for Outdoor Lighting Replace floodlight and area light fixtures with LED lighting fixtures. 11 Boiler Reset Controls Add controls to boiler systems to reset hot water temp according to outdoor temp. 12 High Efficiency Boiler Replace older boiler in Annex with a 90%+ high efficiency boiler and save over 30%. 13 High Efficiency Tankless Water Heater Replace old 100-gallon propane water heater with a high efficiency tankless propane water heater. 14 ENERGY STAR Appliances, Computers, Office Equip. Be sure to specify new appliances, computers and office equipment with U.S. EPA ENERGY STAR rating. Annex (primarily hallways) (Gymnasium) Annex Annex Annex Annex Improve visual acuity; often can increase lighting levels. Improve visual acuity; often can maintain lighting levels. Reduce maintenance. Reduce maintenance. Improve comfort. Less heat generated. D. Capital Intensive ECOs Energy Conservation Opportunity (ECO) Applicable Areas ECO Additional Benefits 15 High Efficiency Heating System Explore the possibility of pairing the dual-fuel boiler with a high efficiency modular boiler system (propane) rather than firing the propane power burner on the dual-fuel boiler. 16 Roof Insulation Additional roof insulation could be installed when the building is due to be re-roofed. Roof More even heating improve comfort. Introductory Energy Evaluation 8

9 Discussion of Energy Conservation Opportunities The individual ECOs from the Summary of Energy Conservation Opportunities are discussed below. From experience, the energy savings for most ECOs will pay for the implementation cost in less than eight years sometimes much less. ECOs involving major building improvements (windows, doors, wall insulation, etc.), sophisticated energy management systems or HVAC system replacements will generally require an engineering study to determine cost-effectiveness. No Cost ECO : Adjust Heating Temperature The recommended heating temperature for offices is 68 o F. However, cooler levels are often possible in other areas such as computer rooms, corridors and storage rooms. Generally speaking, you should try to keep the temperature at the lowest possible level while still maintaining comfort for occupants. As the graphic on the right illustrates, the savings can be quite significant for this measure. For example, it can cost up to 22% more to heat a building area to 72 o F rather than the recommended setting of 68 o F. Likewise, you could save up to 14% by dialing down from 68 o F to 65 o F. Recommended heating temperatures for various public building areas are shown on the left. The temperatures apply to occupied building hours; a reduction to 55 o F is recommended when building areas are unoccupied. However, studies show that over half of the savings available are achieved BUILDING AREA Offices, Classrooms Auditoriums Computer Rooms Restrooms Corridors Gymnasiums Storage Rooms Recommended Temperature o F 68 o F 68 o F 65 o F 65 o F 62 o F 55 o F 55 o F in the first 5-degree setback even a minor temperature setback during unoccupied building hours can produce a substantial savings. Review current heating temperatures in comparison to recommended levels. Significant energy savings can often be achieved for FREE by adjusting thermostats or energy management systems. No Cost ECO : Reduce Plug Loads Plug-loads are devices that plug into electrical outlets such as appliances, office equipment, small space heaters, etc. Studies show that plug-loads are on the increase in office and educational facilities and can be responsible for 10% (or more) of the total electrical load in a building. Plug-loads, in fact, are the fourth highest energy use category after lighting, heating and cooling loads. The table on the right lists several common plug-loads and the typical annual operating cost. Equipment Typical Load (watts) Typical Annual Operating Cost Aquarium (20 gallon) $ Coffee Maker $ Compact Refrigerator $ Computer (desktop) $ Computer (laptop) $ 2 5 Microwave $ Space Heater $ Television $ Typical Operating Cost based on Lawrence Berkeley National Laboratory and U.S. Department of Energy surveys, and average electric rate of $0.10 per kwh. Introductory Energy Evaluation 9

10 It can be helpful to take a survey of all building plug-loads to estimate their total annual operating cost as a first step in reducing this energy use. You ll find that the cost of operating these devices quickly adds up to a substantial expense. Developing a policy regarding the use of these types of devices and discouraging the use of all non-essential plug-load equipment can provide significant savings. When it is possible to disconnect necessary plug-loads during unoccupied building hours, you can reduce their energy use by up to 70%. In some cases, small plug-in timers can be an effective way to provide closer control of this equipment. ECO # 1 : Occupancy Sensors Lighting can be controlled by occupancy sensors and allow operation whenever someone is within the area being scanned. When motion can no longer be detected, the lights shut off. Passive infrared sensors react to changes in heat, such as the pattern created by a moving person. The control must have an unobstructed view of the building area being scanned... doors, partitions, stairways, etc. will block motion detection and reduce its effectiveness. The best applications for passive infrared occupancy sensors are open spaces with a clear view of the area being scanned. Microphonic sensors detect sound and can see around obstructions and are best for areas with cabinets and shelving, restrooms and open areas requiring 360-degree coverage. Passive Infrared Occupancy Sensor (replaces wall switch) BUILDING AREA SAVINGS Offices, Classrooms 25 to 50% Open Offices 20 to 25% Rest Rooms 30 to 75% Corridors 30 to 40% Storage Areas 45 to 65% Some occupancy sensors utilize both passive infrared and microphonic technology, but are usually more expensive. They can be used to control one lamp, one fixture or many fixtures. The ideal use for occupancy sensors is an area where lighting is often left on after the last person has left the area. The table on the left provides typical savings achievable for specific building areas, as determined by EPA studies. The average savings produced by occupancy sensors, according to the EPA, is 60%. Rooms with lights controlled by a single switch can be retrofit with a wall switch occupancy sensor. Rooms that have multiple switches can have the lighting circuit controlled by an occupancy sensor to allow continued use of switches for preferred lighting level. Any rooms with irregular use, restrooms, storage areas and offices usually provide the best opportunities. You may have to experiment with several types of sensors at several different room locations to find the best fit for your situation. A qualified lighting engineer can help determine the best occupancy sensor solution for your buildings. Consider using occupancy sensors to control lighting in the offices, kitchen, bathrooms, and Annex. Introductory Energy Evaluation 10

11 ECO # 2 : LED Exit Sign Lighting The development of light emitting diodes (LEDs) has allowed the replacement of exit sign lighting with a more energy efficient alternative. LED exit signs consume 90% less electricity than incandescent and 50% less than compact fluorescent fixtures. A major benefit is the 20-year service life of LEDs they virtually eliminate exit sign maintenance. Replace Gymnasium exit sign lighting with LED technology. ECO # 3 : Programmable Thermostats The recommended heating temperature for most building areas is 68 o F during occupied hours and 55 o F when unoccupied. Cooler levels are often possible in storage areas, entries and hallways. Generally speaking, you should try to keep the temperature at the lowest possible setpoint while still maintaining comfort for occupants. A common misconception is that a heating system runs longer after a temperature setback and cancels out the energy saved during the setback period. The graphic illustrates the savings potential for a facility with a 65 o F to 55 o F setback during unoccupied hours. Energy use is higher during the boost period (see graphic), but it only offsets the energy saved during the coast period. Overall, a net savings is achieved, as shown. A programmable thermostat can reset the temperature for you automatically and pay for itself quickly due to excellent energy savings potential. Consider replacing standard thermostats, primarily in classrooms, with programmable ones to perform automatic temperature resets during unoccupied building hours. It may be possible to adjust the MAIN thermostat (which is programmable) to a more efficient setting. ECO # 4 : Compact Fluorescent Lamps (Option # 1) The compact fluorescent lamp (CFL) is an energy efficient alternative to incandescent lighting. CFLs provide equivalent lighting, consume 75-80% less energy and last 5 to 15 times longer than incandescent lamps. At one time, the application of a CFL was somewhat limited mainly the replacement of a 60-watt light bulb on a non-dimming circuit. Now there are many types of CFLs available for a wider variety of purposes. Improvements in ballast technology have enabled CFL use outdoors in cold weather and with dimmers, too (but only as specified). They re also available in smaller sizes, and several shapes have been developed to provide more versatility. Introductory Energy Evaluation 11

12 Some basic CFL shapes that are now available for most applications are shown below. Coiled CFL Quad-lamp CFL Flame-tip CFL CFL Reflector Lamp CFL A-Lamp Consider replacement of 300W incandescent lamps in Gymnasium ceiling fixtures and wall lanterns outside gym entries with appropriate size compact fluorescent lamps. ECO # 5 : Control Beverage Machine Energy Use Refrigerated beverage machines operate 24 hours/day, often with display lighting operating continuously. The lighting produces heat which adds to the load on the compressor, increasing refrigeration cost. Disconnecting the ballast and lamps can save over $75 per year! During periods the building is unoccupied, a beverage machine can be turned off. With an operating cost greater than that of a large refrigerator, the savings potential for turning it off whenever possible is significant. There is now a power controller available that is activated by an occupancy sensor that will shut the machine down when the area is unoccupied primarily during night hours. The Vending Miser (shown on left) will not shut the machine down while the compressor is cycling, which can be harmful, Plug-in Power Controller Occupancy Sensor and is approved by several of the major drink companies. Consider installing a sensor for your beverage machine. Remove Fluorescent Lamps and Disconnect Ballast Inside Pop Machine ECO # 6 : Hot Water Conservation A substantial amount of hot water is often used in kitchens to pre-rinse dishes before washing. With typical flow rates of 2.65-gpm to 6.0-gpm, the water consumed by pre-rinse sprayers (and the energy used to heat that water) can be significant. High velocity pre-rinse sprayers have been developed that use 50-80% less water while providing excellent performance in fact, 1.28-gpm water saving pre-rinse sprayers are out-performing older models in tests. Introductory Energy Evaluation 12

13 Pre-rinse sprayers in kitchen dishwashing areas can be replaced with water saving 1.28-gpm models for less than $100 each. The water savings coupled with reduced water heating will usually pay for the cost of this measure in less than one year. Consider retrofitting the pre-rinse spray valve in the kitchen dishwashing area with a 1.28-gpm pre-rinse sprayer. ECO # 7 : High Efficiency Fluorescent Lighting System T5 and T8 fluorescent lamps powered by electronic ballasts use 20-50% less energy than standard T12 fluorescent lamps. T8 fluorescent lamps are a 1-inch diameter lamp compared to the 1½-inch diameter T12. They are available in common lengths, but the 4-foot T8s are most popular. Fixtures with 8-foot lamps can often be retrofitted with 4-foot lamps (installed end to end), which are more stable, less expensive, and have a 33% longer service life than 8-foot lamps. The T8 fluorescent has become the standard for office, classroom and general area lighting applications with ceiling heights under twenty-four feet. T5 fluorescent lamps are even thinner with a diameter of 5/8-inch. The T5 system cannot be easily utilized as a retrofit in most cases, new fixtures are required. The thinner size, however, enables greater lighting control and focus. T5 fluorescent lighting systems tend to provide a more intense light, especially with T5 high output (HO) lamps, and are best suited for general area lighting applications with ceiling heights over twenty feet. Careful, proper design is needed at lower heights to prevent glare from becoming a problem. Besides energy efficiency, T5 and T8 fluorescent lighting provide higher quality illumination. Color rendition is better and there is no detectable flicker (often exhibited by standard fluorescent fixtures). As a result, visual acuity is improved. Studies have actually confirmed increased productivity under T8 fluorescent lighting, in particular. Consider replacing all T12 fluorescent lighting with T8 fluorescent lighting. Many fixtures can be retrofitted with this technology. A minimum savings of 20% on lighting can be achieved. ECO # 8 : T8 Fluorescent Lighting and Specular Reflector Retrofits A specular reflector can be installed in a fluorescent fixture, improving reflectance and allowing the removal of one or two lamps from multiple-lamp fixtures with just a 10-25% reduction in the lighting level. The reflector focuses the light more efficiently standard fixtures absorb some of the light output and reflect the rest in a diffuse and unfocused manner. Four-Foot 4-Lamp Fluorescent Fixture Retrofit with Reflector and (2) T8 Fluorescent Lamps Introductory Energy Evaluation 13 Specular Reflector SPECULAR REFLECTOR

14 A specular reflector can be installed in a fluorescent fixture, improving reflectance and allowing the removal of one or two lamps from multiple-lamp fixtures with just a 10-25% reduction in the lighting level. The reflector focuses the light more efficiently standard fixtures absorb some of the light output and reflect the rest in a diffuse and unfocused manner. We recommend that a lighting engineer or electrician be consulted regarding the optimum specular reflector and T8 lamp configuration for your facility. Where lighting levels exceed acceptable ranges, consider retrofitting each 4-lamp fixture with two T8 lamps, electronic ballast and specular reflector. A savings of more than 60% on lighting can be achieved. ECO # 9 : Induction Lighting (Option # 2) Induction lamps are somewhat similar to fluorescent an electric current is generated within a glass bulb to excite gases, stimulating the emission of ultra-violet light that is converted to visible light by phosphors lining the inside of the bulb. High Frequency Generator Power Coupler However, induction lamps utilize a high frequency generator to create an oscillating magnetic field that induces the electric current through a power coupler inside the bulb filaments or electrodes are unnecessary. This extends lamp life substantially since filaments and electrodes are the main failure points that limit service life in incandescent, fluorescent, and metal halide/high intensity discharge lamps. Induction lamps typically last 50, ,000 hours, and much longer than other light sources. A small amount of phosphor degradation occurs over time, but the life of the bulb is essentially indefinite. Therefore, the rated life of an induction lamp is based on the life of the electronic components in the power supply rather than failure of the lamp itself. Glass Bulb 80W Induction Surface-Mount Fixture Besides possessing a service life that makes this technology almost maintenance-free, induction lamps are energy-efficient, provide long-term stable white light with high lumen maintenance and have instant-on capability. They are readily available in 55-watt up to 400-watt sizes in several shapes and are well suited for many applications, but should only be specified by a qualified lighting specialist. Licensed electricians or lighting engineers with experience in advanced lighting technologies should be consulted regarding the feasibility of this measure. Consider replacing 300W incandescent light fixtures in the Gymnasium with 80W induction surface-mount canopy fixtures (or another appropriate style at possibly lower wattage) to save over 70% and increase lighting levels. Introductory Energy Evaluation 14

15 ECO # 10 : LED Fixtures for Outdoor Lighting The development of light emitting diodes (LEDs) has provided a very energy efficient lighting alternative to incandescent, compact fluorescent and even high intensity discharge lamps for certain outdoor lighting applications. LED fixtures can often produce equivalent lighting while consuming 50-90% less electricity. A major benefit is the long life of LEDs the 50,000 hour minimum service life of this product virtually eliminates maintenance requirements for years. The picture below shows an LED outdoor lighting upgrade in progress at the United States Army Garrison Humphreys in the Republic of Korea. The sharp contrast between the 56-watt LED wallpack fixtures installed above the overhead doors (bright white light) versus the 250-watt high pressure sodium fixtures (amber light) is striking. And, after the remaining fixtures are replaced with the LED wallpacks, the project will achieve an 80% savings on outdoor lighting. Recent research at the Lawrence Berkeley National Laboratory has shown that lighting color has a major impact on visual acuity bright white light near the blue end of the spectrum is preferable for optimum vision and clarity. Essentially, we can see better under bright white light at a lower lighting level than amber light at a higher level, as clearly illustrated above. Full Cutoff Wallpack Standard Wallpack Canopy Fixture Recessed Can Semi Cutoff Wallpack Mini Wallpack Floodlight Spotlight Wall-Mount Downlight Consider utilizing LED wallpack fixtures, floodlights, or other options as replacements for fixtures lighting the building grounds outside the school buildings. Introductory Energy Evaluation 15

16 ECO # 11 : Boiler Reset Controls Boiler systems commonly maintain a fixed supply water temperature (usually 180 o F). The water temperature is higher than necessary most of the time, but is kept at this level to be able to heat the building on the coldest days of the year. This practice is inefficient since buildings can often be heated with lower temperature water more than 80% of the time. A boiler control that monitors outdoor conditions and resets the water temperature to the lowest possible level will save significant energy. In the past, a single control to perform this function was installed. Today, with the advent of electronic controllers, a boiler energy management system can be added to handle temperature resets and other energy saving measures. The energy management system (EMS) below is an example. Besides temperature reset, an EMS can shut down the boiler system when the outdoor temperature reaches a certain point (usually 65 o F), but still maintain a minimum temperature during warm weather shutdown (required for certain boilers). It also has the capability to run the boiler system at a minimum level when the building is unoccupied. If there is more than one boiler (modular system) or if your boiler has multiple stages, the EMS can cycle the boiler(s) as needed rather than all at once to increase efficiency. This multi-staging also ensures equal cycles, extending boiler life. Finally, indicator lights or an LCD/LED display allows you to monitor the status of the boiler system operation at a glance and can be very helpful. Boiler Energy Management System Consider boiler energy management systems to vary water temp with outdoor temperature and enable warm weather shutdown on both the and Annex systems. ECO # 12 : High Efficiency Boiler System Older boilers have seasonal efficiencies of 55-60%... of the fuel burned, 55-60% is converted to space heat and 40-45% is lost up the chimney. Improvements to burners, heat exchangers and controls have pushed efficiencies above 85% on the new high efficiency boilers. Sealed, pulse combustion boilers have been rated above 90%. Substantial savings can be achieved by replacing older boilers with the high efficiency systems now available. Boiler systems operate most efficiently under full-load when system heating capacity is equal to the building heating load and, as a result, it must fire continuously to maintain temperature. But, because boilers are typically sized big enough to be able to heat buildings on the very coldest day of the year, full-load conditions rarely ever occur. As the chart shows, the heating load is regularly 60% (or less) of the boiler s heating capacity, which significantly decreases system efficiency. 100% 80% 60% 40% 20% Heating Load as a Percentage of Boiler Heating Capacity (Annual profile for typical heating system operation) Introductory Energy Evaluation 16

17 A modular boiler system consists of a series of smaller boilers that operate on demand. Utilizing an electronic controller, the boilers are staged to fire as necessary to meet the changing heating load of the building. Generally, modular systems provide a quicker response to heating needs and less standby loss during unoccupied building hours. Some of the newer, larger boilers can achieve the same effect with modulation controls, which automatically adjust the boiler heating capacity (down to 20% of rated capacity) depending on heating load conditions. Modular and modulated boiler systems maximize energy savings when high efficiency equipment is used. A boiler replacement strategy is suggested below. We recommend that you consult licensed heating contractors for more information and actual pricing to implement this measure. Consider replacement of the Annex boiler with a 90%+ high efficiency boiler save over 30%. ECO # 13 : High Efficiency Tankless Water Heater Replacing an old water heating system with a high efficiency tankless system can often provide a substantial energy savings. Tankless models heat water on an as needed basis and utilize a more efficient method to heat the water through improved burner design. Eliminating the storage tank saves 10-15% by itself and, with the 93% efficient condensing heaters now available, high efficiency tankless systems can save up to 50% compared to conventional water heaters. Tankless water heaters have an average service life of 20 years, 50-60% longer than conventional models. Plus, tankless water heaters are serviceable and can be repaired, whereas tank-type models are often replaced when problems arise. The longer life cycle, in general, negates the higher initial cost of these systems. The picture on the right shows a 93% efficient high efficiency tankless water heater that can deliver 8-11 gallons of hot water per minute virtually continuously. Notice the PVC exhaust and outside air intakes, trademarks of a 90%+ efficient system. If greater capacity is required, a series of units can be plumbed together and operate according to demand utilizing just a single controller, staging the units as required. A qualified plumbing contractor with experience in these types of systems can advise you further on this measure. High Efficiency Commercial-Grade 93% Efficient Tankless Water Heater Consider replacement of the old 100-gallon propane water heater with a high efficiency 90%+ tankless propane water heater. ECO # 14 : ENERGY STAR Appliances, Computers & Office Equipment Energy costs associated with electrical plug loads should be minimized where possible. Plug loads are electrical devices plugged into the building s electrical system and generally include things like appliances, window air conditioners and office equipment such as computers, printers, and copiers. When purchasing this kind of equipment, the U.S. EPA ENERGY STAR standards Introductory Energy Evaluation 17

18 should be specified. Manufacturers are required to meet certain energy efficiency criteria before they can label a product with the ENERGY STAR emblem, so these products represent your best energy saving value. ECO # 15 : High Efficiency Heating System Due to the increasing cost of propane, it may be worth considering replacement or a re-working of the existing heating system in the. Standard boilers have an AFUE of 55-60%; of the fuel burned during the course of a winter, 55-60% is converted to space heat and 40-45% is lost up the chimney. The power burner on the dual-fuel boiler is probably providing more efficient performance than a standard atmospheric burner in a standard boiler system, but this equipment is now 20-years old. Significant savings may be achievable by pairing the wood boiler with a high efficiency propane boiler system, if such a configuration is possible. We recommend consulting your boiler manufacturer to determine the feasibility of this measure. Explore the possibility of pairing the dual-fuel boiler with a high efficiency modular boiler system (propane) rather than firing the propane power burner on the dual-fuel boiler. ECO # 16 : Roof Insulation Heat flows from warm areas to cool areas. Insulation slows down this heat flow which will save both heating and cooling energy. The amount of savings is dependent on the thermal resistance (R-value) of the insulation. The higher the R-value, the more effective the insulation is at slowing down heat flow. Since warm air rises, it is important to make sure the roof area is adequately insulated. Additional insulation can be installed from the interior or exterior, depending on the type of roof structure present. Methods of application include: (1) Interior Roof Insulation - In some buildings, the insulation can be applied directly to the underside of the roof structure. If the structure is wood frame, insulation (rigid or blanket) can be placed between roof joists. For metal roofs, foams or mineral fiber can be sprayed onto the roof surface underside. (2) Sprayed On Foam - This type of insulation is applied to the exterior roof surface (usually metal). A thin protective coating is then added to act as a weather shield. (3) Rigid Insulation w/ New Roof - When the existing roof needs to be replaced, it would be wise to install two inches of rigid foam beneath the new membrane. Due to the expense, this method is rarely considered until re-roofing is necessary. At Whitefish Township Community School, additional insulation could be added by applying several inches of rigid foam insulation the next time the building is re-roofed. Introductory Energy Evaluation 18

19 Appendix A: Energy Consumption Profiles Whitefish Township School.page 20 Whitefish Township School Annex.page 21 Introductory Energy Evaluation 19

20 Whitefish Township School 7221 North M-123 Paradise, MI Electric Consumption Profile (kwh) 9,000 8,000 7,000 6,000 5,000 4,000 3,000 2,000 1,000 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Propane Consumption Profile (gallons) 1, Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month kwh Cost Jan ,342 $966 Feb ,039 $931 Mar ,855 $794 Apr ,069 $818 May ,797 $820 Jun ,865 $587 Jul ,280 $396 Aug ,938 $475 Sep ,999 $724 Oct ,651 $803 Nov ,894 $832 Dec ,907 $954 Totals: Elec ECI: Elec EUI: Average Cost: $ / kwh Month Gallons Cost Jan $1,417 Feb $1,381 Mar $1,565 Apr $1,755 May $655 Jun $0 Jul $0 Aug $0 Sep $0 Oct $605 Nov $757 Dec $739 Totals: Propane ECI: Propane EUI: Average Cost: 76,636 $9,101 $0.57 per sq ft / yr 16,347 BTU / sq ft 4,259 $8,875 $0.55 per sq ft / yr 24,385 BTU / sq ft $ / gallon Electricity % of Cost : Propane % of Cost : Building Type: K-12 School Age / Year Built: % Whitefish Township School * Annual Cost = $24, % Building Area: 16,000 sq ft * Energy Cost Index = $1.52 Energy Star Rating = 40 * Energy Use Index = 107,139 DHW: Elec 30-gallon, propane 100-gallon Interior Lighting: T12 fluorescent (majority) Heating: 1991 dual-fuel boiler (w ood/prop) 300W incandescent (gym) Walls: Brick / masonry Cooling: None Exterior Lighting: Q-H flood, inc, HID area Roof: Flat roof, some insulation Distribution: Unit vents, cabinet heaters Other: Commercial refr, freezer, range, Window s: Double glazing Temp Control: Prog (main), standard stats pop machine, computers * Includes 85 tons of w ood $6300 total cost; 1 ton w ood chips = 12.5-million BTUs Introductory Energy Evaluation 20

21 Whitefish Township School Annex 7221 North M-123 Paradise, MI ,400 1,200 1, Electric Consumption Profile (kwh) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Propane Consumption Profile (gallons) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month kwh Cost Jan ,358 $157 Feb ,315 $152 Mar ,092 $126 Apr $75 May $28 Jun $27 Jul $19 Aug $24 Sep $47 Oct $101 Nov ,189 $144 Dec ,186 $143 Totals: 8,838 $1,045 Elec ECI: Elec EUI: Average Cost: $0.38 per sq ft / yr 10,929 BTU / sq ft $ / kwh Month Gallons Cost Jan $896 Feb $505 Mar $305 Apr $678 May $379 Jun $0 Jul $0 Aug $0 Sep $0 Oct $148 Nov $374 Dec $458 Totals: 1,852 $3,745 Propane ECI: Propane EUI: Average Cost: $1.36 per sq ft / yr 61,478 BTU / sq ft $ / gallon Electricity % of Cost : 21.82% Whitefish Twp School Annex Annual Energy Cost = $4,790 Building Area: 2,760 sq ft Energy Cost Index = $1.74 Natural Gas % of Cost : 78.18% Energy Star Rating = N/A Energy Use Index = 72,407 Building Type: K-12 School auxiliary bldg DHW: None Interior Lighting: T12 fluorescent Age / Year Built: 1980 Heating: Std eff propane boiler Walls: Concrete block, framed, insulated Cooling: None Exterior Lighting: HID area lights Roof: Flat roof, some insulation Distribution: Baseboard, unitary heater Other: Shop pow er tools Window s: Doublepane Temp Control: Standard thermostats Introductory Energy Evaluation 21