Reduce Building Energy Use and Cost with New Operations & Maintenance Measures

by Michael J. Madigan, Robert M. Neimeier and Stuart J. Spiegel — During an 18-month period (2009-2010), our authors, from O’Brien & Gere, an employee-owned engineering and project delivery company, performed high-level energy assessments of over 20 million gross square feet of building space, consisting primarily of college campuses and also multiple industrial buildings.

The assessments benchmark well to the American Society of Heating Air Conditioning and Refrigeration Engineers (ASHRAE) Level 2 energy audit (“Energy Survey and Engineering Analysis”), the standard procedure that includes detailed energy use calculations and a financial analysis of proposed energy conservation measures (ECMs).

Building Energy Assessments

The campus building energy assessments were performed to provide the building operators with the current state of energy-related matters, as well as to identify ECMs. The following activities were performed as part of the assessments:

• Facility O&M staff was interviewed to provide anecdotal information on issues that could disturb energy use. These issues were evaluated in the review of available documentation and data, or the field survey.
• Available record drawings, maintenance records, prior energy studies, reports, and recent energy projects were reviewed for a historical and focused perspective on energy issues relative to a specific building.
• Field surveys were conducted at designated buildings to identify major energy-consuming systems and equipment. Walkthroughs were conducted of building mechanical rooms to identify and document deficiencies, while assessing the physical condition of a building’s mechanical systems.
• Energy procurement records were reviewed to evaluate the distribution of energy consumption between different billing accounts, when in place, and to determine non-building related influences, primarily ambient temperature dependence. In addition, current utility metering systems and equipment for fossil fuel, electrical, and water usage were reviewed to allow for the assessment of potential additional metering needs.
• A night survey was performed to determine light levels and lighting behaviors in unoccupied buildings. The survey was intended to highlight lighted areas so that functionality for security needs could be applied where appropriate.

New Energy Reduction Measures

Observations resulting from the energy assessments were used to help building operators address energy consumption efficiency. With low or no additional cost, significant reductions in campus energy use can be achieved through building occupant behavioral changes, increased energy awareness, and O&M practices.

Install weatherstripping to prevent window and door leaks. Photo courtesy of O’Brien & Gere

The following ECMs were commonly identified during the energy assessments, indicating that building operators can benefit from evaluating their applicability.

1. Turn off unnecessary lights, especially in unused offices, closets, classrooms, and conference rooms. Occupancy sensors are often blocked or inoperable, which indicates that units installed because of an energy audit binge in the early 1990s may have reached the end of their operational life. The most recent generation of infrared and ultrasound is operationally superior to these older units, so also consider investing in new, more reliable sensors.
2. Turn off air conditioning units and fans when buildings are unoccupied. Central systems provide opportunities for energy and cost efficient control strategies like occupied and unoccupied temperature settings, economizer cooling, and remote monitoring of space temperatures. Where a window unit is necessary, keep doors and windows closed and turn the unit off when out of use to reduce energy costs with no capital expenditure.
3. Turn off lights in common areas and corridors when no one is present. Occupancy sensors are now used more routinely in common areas than in the past; however, buildings fitted with occupancy sensors in the early 1990s generally did not include common areas in their coverage. These areas may be preset to a low light level for safety reasons and an increased light level when a person enters to reduce energy costs with little capital expenditure.
4. Use care when renovating spaces after reprogramming buildings or floors. Often, spaces are separated in ways that indicate inadequate consideration of air flows and HVAC needs, since walls and partitions block the air flow originally designed for the spaces. These situations result in wasted energy as systems respond or perform inappropriately.
5. Enforce a campus-wide temperature set point policy in the winter and summer seasons. Implementing this policy and communicating it to building occupants will increase awareness that behavior affects energy use in the facility. While employing the policy may require changing building occupants’ expectations, the energy savings potential is substantial, and the implementation cost is minimal.
6. Repair or replace door and window weather stripping, and seal openings to reduce air infiltration. Repairing these seals will reduce air infiltration, thereby reducing heating and cooling costs and improving local occupant comfort.
7. Provide low-wattage infrared space heaters or avoid space heater use entirely. Likewise, utilize computer peripheral switching, eliminate private office kitchenettes, and address other plug loads. Many identified electrical plug loads could be eliminated through behavioral and policy changes at minimal cost. Reducing, eliminating, or prohibiting unnecessary electrical plug loads saves electrical costs year-round and reduces air conditioning loads during summer months.
8. Utilize PC software that offers network level control over power management settings. Set computers, monitors, printers, copiers, and other business equipment to energy-saving features and turn off at close of business for significant savings.
9. Purchase equipment with the U.S. Environmental Protection Agency (EPA) EnergyStar rating when possible. In addition to reducing campus energy consumption, widespread acceptance of EnergyStar as a consumer preference sends a positive message to manufacturers that could transform the marketplace for energy-consuming products.
10. Procure or require vendors to provide EnergyStar vending machines that shut down or operate at reduced energy levels during unoccupied periods. Applying these sensors to refrigerated and non-refrigerated vending machines can reduce electrical energy consumed during unoccupied periods. In non-refrigerated machines, the controls turn off the vending machine lighting after a preset interval when no one is in the vicinity. In refrigerated machines, the controls turn off machine lights and the refrigeration compressor after completion of the cooling cycle.
11. Improve planned maintenance practices. For example, plan for piping and duct leak repairs, abandoned equipment removal, frequent coil cleaning and filter changes, and other routine practices. Failure to repair pipe leaks creates safety issues, wastes energy, and reduces the effective life of the equipment.
12. 

    Improperly installed A/C units result in infiltration and wasted energy. Photo courtesy of O’Brien & Gere

    Change hot water supply temperature set points based on outdoor temperature conditions. Maintain automatic temperature control systems. Higher water temperature set points require more energy consumption than lower water temperature set points.

13. Perform regular maintenance on steam traps. Failed or poorly performing steam traps can waste large quantities of thermal energy.
14. Clean or replace air filters at regular recommended intervals. Clean heating and cooling coils periodically. Cleaning filters and coils saves energy, improves energy performance and comfort, and extends the life of the equipment.
15. Provide ongoing training of facilities staff in the operation and maintenance of campus systems and controls. A trained maintenance staff understands the underlying principles behind the systems in their care and has the tools to operate the systems at peak efficiency.

Based on observations resulting from the assessments, the team identified a number of measures that building owners and operators can implement to improve energy use.

A Building Management System, or other computerized building monitoring system, may be the best way to control energy, lighting and other costs. But in today’s tight economy, when it may be impossible to make the up front investments in these systems, following simple O&M procedures like the one above will provide tremendous time and cost savings with nearly immediate payback.

This article was Co-authored by Michael J. Madigan, PE, LEED AP, QCxP, project manager for Energy Practice, Robert M. Neimeier, senior project manager with Greenhouse Reduction and Climate Change Management Programs, and Stuart J. Spiegel, vice president, Market Sector Leader for Higher Education, O’Brien & Gere, a national engineering and project delivery company headquartered in Syracuse, New York. They can be reached at info@obg.com.