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WMU Energy Reduction
Sales Order LookupWMU Energy Reduction
Western Michigan University is actively pursuing energy conservation and reduction on a very large scale.
Based in the Physical Plant, Maintenance Services Division, the Energy Reduction Manager plans, coordinates, implements and monitors the energy reduction efforts of the university. That does not mean that only one person is doing this work. There are many others on the team. From top management to the installing and maintaining technicians, all are needed to support the efforts.
Prior to the creation of an Energy Reduction Manager, a number of people were involved in energy conservation. The projects included motor upgrades, lighting upgrades, and the ongoing Steam Trap Program. This Steam Trap Program started by George Jarvis has saved significant amounts of energy for the university.
The Energy Reduction Office also coordinates all of the metering on campus. Projects are underway to upgrade the existing electric metering on campus to a revenue grade, electronic metering system for more accurate costing of energy consumption. This is also to be used in estimating and verification of Energy Conservation Measure [ECM] projects. Projects are also underway to install metering for the steam consumed on campus. Steam metering is difficult to do. The decision has been made to measure condensate from the steam [water] and then convert that quantity to an equivalent amount of steam. This again is an effort to better understand the efficiency of our buildings.
Lighting conversion is a large target for energy reduction on campus. There are many incandescent lamps being used that are methodically being phased out. Compact Fluorescent Lamp [CFL] technology has grown significantly in the last 5-8 years. Where it is possible and practical CFL’s are being installed on campus. Standards for new construction are being changed so that incandescent lamps will no longer be allowed unless absolutely necessary. Conversion of many existing old style fluorescent lighting [T12] using magnetic ballasts and 34 watt lamps to modern fluorescent lighting [T8] using electronic ballasts and 32 watt lamps has been completed in several buildings. Many are yet to be done.
Metal Halide lighting is also being converted to fluorescent for higher efficiency and better quality lighting. The conversion of the Student Recreation Center is an example of this effort.
The Heating, Ventilation, Air Conditioning [HVAC] systems on campus are another big consumer of energy. There are quite a few items on the list of controlling energy that are being done to reduce energy costs with this equipment.
In the past the HVAC equipment has been controlled by air pressure controls [pneumatic]. These are the hissing thermostats that may be heard in some of our buildings. These are inefficient and costly to maintain. Some electric controls are also still in use. The proven technology today is electronic control called Direct Digital Control or DDC. These DDC systems are called Building Automation Systems [BAS]. This technology uses electronic thermostats, sensors, and controllers to operate the HVAC equipment. HVAC Air supply used to be constant volume into a space. Now a Variable Air Volume [VAV] control is being used to provide the proper amount of air flow to a space to provide comfort to the occupants. If there is excess flow, the control box partially closes to reduce the flow. This flow change is sensed by components of the main air handling unit so that the fan speed of the unit can be slowed down. Slowing down the fan saves the unneeded air flow and saves the horsepower of the fan which saves money. The device that controls the fan speed is called a Variable Speed Drive or VFD. VFD’s are also used on pumps and cooling towers to match the demand of the space with the proper energy supply.
DDC systems also allow the consistent use of Time of Day scheduling. This function programs the HVAC to operate at an appropriate time of day for the scheduled activities of any given building. It also allows for the use of occupied set-points for temperature, standby set-back temperatures, un-occupied time setback temperatures and the appropriate response of the system to return to occupied set-points. TOD along with Occupancy Sensors provides us the most efficient method of controlling the temperatures in our spaces and thus saving energy dollars.
A very big part of the DDC technology is communication with every building on BAS via our computer network and the internet. From behind protected firewalls graphical screens are visible connections to what is actually happening in our buildings. Programming and shared data are also accomplished via the various screens and connections to the buildings. Trouble shooting of problems via the university wireless network using the graphics screens is also a valuable tool to our technicians.
A big factor in saving energy is the implementation of our Set-Point Policy. Prior to the implementation of this policy, each building space temperature could be adjusted according to different occupant wishes. The temperature could be as high or as low as desired, and could be changed many times. This policy restricts the temperature range in each space controlled by DDC. Our heating limit is 69 deg. F., and our cooling limit is 75 deg. F. This means that above 69 deg we do not add heat to a space. Below 75 deg we do not add cooling to a space. However, in the process of supplying sufficient fresh air to an occupied space, some residual heating and cooling may take place, thus raising or lowering the temperature a bit from the set-point limit.
With TOD in place, we are also able to implement a Holiday Setback schedule. This basically puts a classroom or office into a round the clock night setback temperature and HVAC program. The fans do not run unless it is needed to keep within the night setback temperatures. We are also able to put the entire campus into a special deep setback program when the university is closed at the end of the Fall Semester. We also are able to put the residence halls in a setback mode during the semester closure when no students are living in the halls.
A major component of our energy efforts is the use of Occupancy Sensors in the Building Automation System. We use the sensors to turn off the lights when a space is empty and to put the space into the appropriate occupied mode or setback mode. This is what closes the VAV box and slows down the fan motor as explained above when the space is empty.
In the heat of summer, cooling is in high demand. That high demand puts a strong need for electric power to operate our electric chiller systems. This high demand in the summer determines what our maximum demand is from the electric power provider for WMU. The higher the demand, the higher the cost of electricity during the peak demands periods. One of the things that our BAS does for us is to turn off the electric chillers on campus for 30 minutes per day on those days when the demand is above certain levels. The chillers are rotated so that only one at a time is off. The sensing of the peak demand periods is now done by sharing data between the BAS control center in Physical Plant. and the WMU Power House. This is done electronically. The Power plant also has access to the BAS for monitoring purposes on their end.
WMU utilizes Heat Recovery where possible and practical. We recover the heat from the ice making machine at Lawson Arena to heat the Pool in Gabel Natatorium next door. The exhausted heat and air conditioning at West Hills is recovered to pre-heat or pre-cool the intake air. Free cooling is being used in one instance in the accelerator lab to provide cooling to the equipment and people in the space. This space requires cooling year around. When the outside temperature reaches a certain level, the chillers are turned off and a simple heat exchanger transfers the heat to the outside of the building bypassing the chillers.
Daylight harvesting is being utilized where possible. This is a process where a sensor detects sufficient outdoor light coming in through windows that allows us to turn off the lights and use just natural daylight. The new Michigan Energy Code now requires this. WMU has been doing daylight harvesting for about 8 years in some buildings.
Water conservation is practiced where possible. This has not been a large project, but low flow shower heads, sinks and toilets have been implemented on a gradual basis. Waterless urinals have been tested for practicality and savings. Occupancy sensors were installed in the Bill Brown Public Restrooms that were being left continuously flushing by the building occupant. These sensors now turn off the lights and turn off the water flow when no one is in the space. Our cooling tower water treatment has been upgraded so that the towers do not use as much water as they used to. We also are now getting credit for the water that evaporates from the towers that does not go down the sewer line. We used to get charged sewer costs for water that did not go into the sewer, but up in the air. Auxiliary Enterprise last year installed new washers in the various locations on campus. These Energy Star rated washers use far less water than older ones, plus the motors are much more efficient. We also are targeting water cooled compressors for HVAC and food storage in a number of places for replacement to a re-circulated water cooling system.
In the last 9 years, as of July 1, 2006, WMU has invested $4.5M in Energy Conservation Measures. The cost avoidance resulting from that investment has been approximately $16.9M. The rough payback has been 1.99 years. Current projects that are being implemented this year are working with a 4-5 yr payback. Several are estimated to be less than 4 yrs. The Return On Investment [ROI] is averaging 25-40%, while several have been higher.
WMU will continue to pursue energy efficiency as much as is possible. Energy conservation is good fiscal responsibility and good ecologic responsibility.
