A Building Automation System (BAS) for the University of Colorado Denver and the Anschutz Medical Campus uses computer panels to control building mechanical systems such as heating, ventilating and air conditioning. Inputs such as temperature sensors tell the system about the conditions of the space and the equipment. Then outputs from the system control the equipment. The control strategies are accomplished by the computer instead of with physical control components. This allows a wide variety of control strategies resulting in greater energy efficiency and occupant comfort.

Auditoriums and classrooms can be easily scheduled from a single workstation instead of walking to each piece of equipment and adjusting time clocks. The computer can estimate how long it will take to get the space comfortable each day so the equipment can be turned on closer to when needed. Equipment can be programmed to heat or cool the space as quickly and efficiently as possible further reducing the time the equipment needs to be on.

Turning off equipment when it is not needed, matching the operation of the equipment more closely to the actual needs of the space, avoiding heating and cooling at the same time are some of the ways a BAS optimizes equipment control. Equipment problems that waste energy or effect occupant comfort and safety can be alarmed and paged to alert people of a problem instead of being discovered sometime later.

A BAS can be used to optimize other energy conservation measures such as variable air systems, variable pumping systems, evaporative cooling, and heat recovery systems.

CU Denver began installing a BAS at the Ninth Avenue Campus in 1984 primarily to save energy. This system was expanded to cover most of the major building mechanical systems before the move to the Anschutz Medical Campus was planned. A BAS is an integral part of all the new construction on the Anschutz Medical Campus. The system in the new campus will provide almost all the control from the large air handling systems to the small dampers and coils controlled by a sensor in the space.

The university's Central Utility Plant (CUP) produces steam and chilled water on the Anschutz Medical Campus for the university, UCH, TCH, and the City of Aurora. The steam produced is used for heating, humidification, sterilization, and testing. The chilled water produced is used for comfort and equipment cooling.

The CUP is more energy efficient, reliable, and offers operational savings as compared to having decentralized boilers and chillers. By having all of the boilers and chillers located in the CUP, larger and more efficient boilers and chillers were purchased. As more steam and chilled water is produced, the cost per 1,000 lbs of steam and ton hours of cooling decreases.

The boilers are operated as efficiently as possible. Fuel is purchased at the lowest possible cost. Maintaining a proper water treatment program that eliminates scale inside of all of the boilers maximizes heat transfer. All of the boilers have economizers installed on them that use some of the waste heat from the flue gas to preheat the feed-water going to the boilers 30F to 40F. All of these items reduce energy costs.

The chillers are operated as efficiently as possible. The condenser water that circulates between the chillers and the cooling towers is cooled down to 60F as often as possible versus the design temperature of 75F. Doing this along lowers the chiller operating cost by 15% to 25%. Maintaining a proper water treatment program that eliminates scale inside of all of the chillers and cooling towers thus maximizing heat transfer. All condenser water tubes in all of the chillers are cleaned annually to ensure that heat transfer is maximized. The speed of all of the large chilled water pumps and the cooling tower fans are controlled by variable frequency drives (VFD). The VFD’s are programmed to operate at the slowest possible speed. At outside air temperatures of 55F or lower, the pressure in the chilled water system is reduced. All of these items reduce energy costs. The latest technology in water treatment control allows chemical to be pumped with precision into the condenser water system. An acid feed system pumps acid into the condenser water system to lower the PH. This allows the water to be cycled 8 to 10 times versus the normal 4 to 5 times. These two items save water. The cooling towers evaporate many millions of gallons of water annually. This water is metered and through an agreement with the City of Aurora, the CUP is not charged sewer charges on this water that is evaporated. This item saves sewer charges.

The CUP is staffed 24 hours a day, seven days a week. The CUP Shift Operations personnel are well trained to respond to operational issues quickly. Decentralized boilers and chillers are not typically overseen by an Operator. If there were to a failure in a decentralized plant, response would be slower and the possibility of equipment damage would be very likely.

Energy efficiency is a very serious topic on the university campus. By employing energy saving measures, not only does the campus save money on operating costs it helps the environment. The environmental cost of producing energy can be tremendous. Burning only one ton of coal to produce electricity releases around 14 lbs of Sulfur Dioxide, 14 lbs of Nitrogen Oxides, and 5187 lbs of Carbon Dioxide into the air. All of which are pollutants that contribute to acid rain and global warming. One ton of coal doesn’t even have the energy content required for an average Colorado home for a year.

Unoccupied Space Temperature Set-Back Program

During holidays or academic breaks, building space often becomes unoccupied. This presents an opportunity to reduce the space temperature set-point and save energy and expense.

Space temperature set-back also reduces greenhouse gases and provides a positive environmental impact at the Anschutz Medical Campus. During this unoccupied time energy use is reduced by lowering the temperatures to the weekend mode in various buildings or portions of buildings. The exact days are limited and will correspond to the days when the University is closed.

Conditions in those areas that are included in this program may be cooler or warmer than normal. If you plan to come in, please expect temperatures similar to weekend set-back temperatures. Please bring or wear extra layers of clothing to make sure you are comfortable.

During the Holidays of the first year when this program was implemented, the University was ableto save energy totaling 201,000 kWh equating to a savings of $12,100 dollars and 144 Metric Tons of Carbon Dioxide Greenhouse gases. This was done with virtually zero impact to building occupants.

Fume Hood Sash Lowering Awareness Campaign

Fume hoods are an integral and important piece of laboratory equipment while conducting medical research at the Anschutz Medical Campus. They also are expensive to operate and consume a significant quantity of energy. This is largely due to the large quantity of conditioned and treated ventilation air that is exhausted. This conditioned air at room temperature is non-recirculated and is 100% outside air. If it is hot or cold outside, this large volume of air still must be tempered to room temperature prior to being exhausted.

Fume hoods are absolutely necessary for research, but the energy consumption can be minimized by manually lowering the sash. New research buildings on campus use technology that varies the air volume when not needed – as indicated by occupant manually lowering the sash (VAV-hoods). When hoods are not in use it‘s a good practice and an energy saving practice to lower the sash.

The University uses an educational awareness campaign to improve occupant understanding of fume hood usage. This includes the use of a magnet placed on the hood with helpful information:

“If left open, this fume hood uses 3.5x the energy of a house! Save up to 60% energy by closing the sash.”

The Facilities Audit process methodically inspects, evaluates and assigns score (FCI # = Facilities Condition Index) to campus buildings and infrastructure. FCI scores are used to prioritize potential Controlled Maintenance projects.

Controlled Maintenance

Controlled Maintenance Projects are major-maintenance improvements that are developed and planned through engineering. These improvements are funded through the State through a standard process for project development, submittal, evaluation, award, and project management.

The university supports the U.S. Green Building Council’s LEED program (Leadership in Energy and Environmental Design) or an equivalent. Campus new construction and facilities operations have incorporated green buildings practices where possible. New projects include energy conservation measures that will save money and lessen our environmental impact. The university is in the process of developing our own program modeled on the popular LEED program with certification to a Gold Standard. Our campus program is focused on reducing our energy cost and embraces sustainable design for the construction of energy efficient buildings.

 

Dramatic energy savings can be seen through the use of energy efficient equipment and materials for construction and renovation of buildings. Although slightly more costly initially than traditional equipment and materials, energy efficient items have a greater payback rate and eventually have the ability to save money. The following are energy efficiency features that some of the new construction projects on campus are incorporating.

Energy Savings Measures for the Anschutz Medical Campus

• Participation in Xcel’s energy savings programs
• Low-E, high visible transmittance window glazing
• Building Automation System control of HVAC equipment and scheduling
• Horizontal window overhangs
• Increased roof and wall insulation
• Occupancy sensor lighting control
• Dual level lighting switching
• Central energy management system lighting sweep after hours
• Lighting manual dimming
• Reduced direct lighting intensity
• Utilization of energy efficient lighting
• Premium efficiency electric motors
• High efficiency electric transformers
• Variable speed drives for electric motors
• CO2 control of outside air
• High efficiency chillers at Central Utility Plant
• Direct evaporative cooling methods
• Variable flow fume hoods
• Building energy recovery systems

By adapting these energy saving methods to some of the various projects around campus and using eco-friendly building practices rather than traditional methods, the amount of energy saved is enough for 1,100 average Colorado homes for 1 year. For home appliance energy use calculators, energy analyzer, ways to save energy and more, visit the Energy Efficiency Tools section of the Xcel Energy website.

Old buildings were built in a time when energy was cheap and the technology did not exist to provide energy efficient alternative to traditional construction methods. The following are things the university is doing to increase energy efficiency in some of the existing buildings.

Building Improvements

• Light Occupancy controls
• Variable speed drives on electric motors
• Improved ventilation and air conditioning controls
• Reduce ventilation in unoccupied labs, offices, and conference rooms
• Improved building heating
• Renovation of building ventilation equipment
• New building control and automation systems
• Replace worn out equipment with energy efficient equipment

Engineering Standards

Engineering develops specific standards as necessary to support operations. Current standards include: metering, infrastructure connections, various building automation requirements, evaporative cooling, custom air-handling-units, and other miscellaneous concerns.

Project Review

Project design documents and construction progress is reviewed for standards compliance, good engineering practice, and overall coordination.

 

A growing alternative to fossil fuel produced energy is renewable energy. Renewable energy usually refers to solar power, geo-thermal, bio-diesel, hydro power and wind energy. Renewable energy is becoming increasingly available, but it still provides only a very small percentage of the total energy needed. It can be much more costly than fossil fuel produced energy, and this higher cost has discouraged its development and widespread use. The university energy provider, Xcel Energy, will be producing 10% of their base rate energy from renewable sources by the end of 2007. Existing legislation mandates this level of renewable energy production by 2015. There is discussion in the 2007 Colorado Legislative Session for mandates for all Colorado energy providers to produce 20% of their base rate energy from renewable sources by 2020.

Currently the university campuses are considering purchasing a portion of its energy from Xcels wind energy program.

Information on possible future options

One source for wind energy is Xcel Energy’s Windsource program. For a fee Xcel will provide wind energy to the grid in the name of the purchaser. There are 77 turbines (and growing) located at 2 wind farms in northern Colorado that currently provide wind energy to the grid (as of January 2007).

For a customer to purchase wind energy they will need to contract with Xcel for a minimum 3 years for a specified number of wind energy blocks. These 100 kWh blocks are currently priced at $1.097. The price varies as allowed by Colorado Public Utilities Commission.

For example if a building uses 100,000 kWh a month and the program was to supply 10% wind energy the monthly cost for 100 blocks will be $110. This cost is a premium to the energy costs already charged on the bill. This will add about 2% to the cost of energy for the building in this example. At 100% wind energy in this example the additional cost premium will be about $1,100 per month which will result in energy costs about 20% higher than our current costs.

More information on Xcel’s Windsource program and current rates.

The University of Colorado | Anschutz Medical Campus incorporates many ECO-Friendly housekeeping methods. See Good Housekeeping for more information on this program.

The Spill Prevention Control and Countermeasures Plan allows for prepared response to emergency spill and/or leak of petroleum containing fuel tanks. For more information, see Spill Prevention.

To minimize pollutants transported by stormwater runoff, the University of Colorado | Anschutz Medical Campus implements programs in accordance with the Non-Standard Colorado Municipal Separate Storm Sewer System (MS4) Permit. For more information on the CU Anschutz MS4 program, see Stormwater Pollution Prevention.

The University works hard to divert waste from landfills through recycling and composting programs. See the Waste Diversion page for more information about these programs and to see what can be recycled and composted throughout the campus.

Lights

Turn off lights in any room when lights are no longer needed. Use the dual switching feature of office lighting. If lighting on both switches is more than you need switch one off.

Computers and Monitors

Use the Energy Saving features in the Control Panel Display setup to disable your screen saver and configure your monitor to turn off after 15 minutes, hard drives to turn off after 30 minutes and enable your system to go into standby mode after 1 hour. Servers should not be turned off, however; the monitor is rarely used and can be turned off. If your computer does not have energy saving features turn off your monitor when idle for an extended period of time. Purchase equipment with the EPA Energy Star label.

Personal Dress

Wear clothing appropriate to the season and weather – lightweight clothing in summer and warmer clothes in winter. Wear layers so you can adapt to varying conditions in your workspace and still be comfortable.

Doors

Vestibule doors should not be propped open and should always close and latch behind you.

Windows

In winter, drapes or blinds should be open when windows are in direct sunlight or you are using the daylight, and closed otherwise. During summer, close drapes or blinds to prevent direct sunlight from entering the room. Try not to use windows for temperature control.

Exhaust Fans

Turn off small exhaust fans when they are not needed. Close laboratory fume hood doors whenever the hood is not being used (and whenever possible, even during use).

Maintenance

Submit a Service Request or call (303)-724-1777 if your work area is overheated in the winter or over-cooled in summer. Do not habitually open a window to get rid of excess heat in the winter.

The University of Colorado | Anschutz Medical Campus aims to ensure that all campus users have an understand how they can support sustainability including the prevention of stormwater pollution. For more information about our educational program, see Education and Outreach.