Managers Need to Address Building-Wide Energy Use
By Gregory Hughel, for Maintenance Solutions, February 2009 www.facilitiesnet.com
Maintenance and engineering managers constantly are looking for ways to make their HVAC systems operate more efficiently and, by doing so, save on energy costs. They also would like to improve indoor air quality and thermal comfort, which would reduce occupant complaints. Maybe most of all, managers would like to extend the life of HVAC systems and components to minimize the frequency of equipment repair and replacement.
The challenge in accomplishing these tasks is deciding where to start. In doing so, it is important for managers to understand the organization’s goals, and more importantly, the goals of the specific facility. A facility’s goals can include saving money through reduced energy use or operating costs, as well as trying to earn a green building certification from rating systems such as the U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED).
Whatever the goals, managers need to understand them first, then build a plan around implementing strategies to enable the organization to achieve those goals.
Potential for Savings
About 30 percent of the energy office buildings consume is wasted, according to the U.S. Environmental Protection Agency (EPA). This finding demonstrates the great potential for energy reduction in existing facilities.
Maintenance departments can reduce energy consumption in many ways, including: commissioning or retrocommissioning buildings to ensure systems are operating according to facility requirements and design intent; conduct energy audits to identify and develop projects that reduce energy use and operating costs; implement a preventive maintenance program; and replace inefficient equipment.
Lighting systems generate about 17 percent of the energy in typical office buildings, while space conditioning and ventilation accounts for 53 percent, office equipment generates 20 percent, and miscellaneous uses make up the remaining 10 percent, according to the EPA.
A building’s mechanical and electrical systems typically account for 70 percent of the office building’s energy use. Managers can present these statistics to facility executives to help generate funding for energy-efficient projects and programs.
Energy Efficiency: Commission for Savings
Commissioning or retrocommissioning is a good starting point when trying to ensure HVAC systems operate at peak energy efficiency. These programs can create an annual energy savings of 5-20 percent.
Commissioning is the process of ensuring a new facility or system performs according to design and the operational needs of the owner. Retrocommissioning takes place after a facility or system is operational. Retrocommissioning consists of testing the functionality of the building and confirming it can achieve the design intent.
The benefits of the processes include: improved energy efficiency; reduced utility costs; better indoor environmental quality; and a better understanding of mechanical, plumbing, and electrical systems.
The cost of retrocommissioning — 27-40 cents per square foot — can be tough for managers to swallow and depends on building size, system type and age, and project complexity. But the payback typically ranges from six months to two years. Commissioning can be more expensive, with an average cost of $1 per square foot and a payback period of about five years.
Conduct Energy Audits to Identity Inefficient Systems
Energy audits are valuable tools for better understanding the way facilities operate. They also provide managers with recommendations for optimizing building systems. Technicians can perform audits at a fraction of the cost of commissioning or retrocommissioning.
Audits systematically identify and develop opportunities that will reduce energy use and, consequently, decrease utility costs. Energy audits identify inefficient equipment, such as older chillers or boilers, that technicians need to replace with more energy-efficient models. The audits also will provide information on optimizing the building’s energy-management system to help determine a balance between energy efficiency and occupant comfort.
Three levels of energy audits exist. Determining the appropriate level depends on a department’s budget and the amount of detail and analysis managers want the audit to generate.
The first and most basic energy audit is the walk-through analysis. This type of audit generally looks at equipment and operational practices. The audit identifies low-cost and no-cost opportunities, as well as the potential savings and simple payback associated with that low-hanging fruit. The audit also identifies items requiring further investigation before managers can receive an accurate recommendation.
The second level of energy audits is the energy survey and analysis. This more detailed audit includes a review and analysis of the installation, design, maintenance, and operations of the building’s electrical, plumbing, and mechanical systems.
The final and most extensive energy audit is a detailed analysis of capital-intensive modifications, which provides managers with the most comprehensive look at building systems. This method involves performing computer modeling of the building to identify potential projects and more accurately determine the projects’ prospective energy savings. The audit also provides schematic layouts and costs for the recommended projects.
Energy audits help managers better understand the way their building functions. As a result, the audits can help managers make educated decisions on determining the best ways to save energy, reduce operating costs, provide more appropriate occupant comfort levels, and create a more efficient building.
Preventive Maintenance Ensures Peak Operating Efficiency
An extensive and detailed preventive maintenance program is integral in ensuring facilities operate at peak efficiency. Preventive maintenance not only helps managers reduce the frequency of equipment replacement and expensive repairs. It also minimizes occupant complaints and increases building efficiency.
Typically, departments should maintain building systems on a seasonal, monthly, or annual basis, depending on the type of equipment. Managers should develop schedules designating the number of hours technicians need to perform maintenance tasks, the individual assigned to each task, the frequency of maintenance, and steps technicians can take to properly complete each task.
Managers can use a spreadsheet to develop these schedules for technicians, or they can use a computerized maintenance management system that issues maintenance requests at set frequencies, provides the equipment’s maintenance history, and holds the staff accountable for completing assigned tasks.
Establishing a preventive maintenance program can ensure equipment is more efficient, which will reduce utility costs and extend the equipment’s performance life.
Retrocommissioning and Energy Audits Produce Quick Payback
A lack of buy-in and financial support is the number one reason most managers never have commissioned or audited their systems. But retrocommissioning projects and energy audits can be more appealing because they typically have a payback period of a couple of years, and organizations can see a significant drop in utility costs rather quickly, especially in older buildings.
Once facility executives buy into the idea of commissioning or an energy audit, they will support the idea of implementing at least some of the recommended projects.
Obviously, managers will implement the low-cost and no-cost recommendations as soon as possible. But major equipment upgrades, such as chiller replacements, do not generate as much support from facility executives. Simple payback based on equipment cost and energy savings will allow managers to determine the projects they should implement.
Managers and facility executives will need to discuss an approach to these retrofits that makes sense as a business decision.
For example, consider an organization leasing office space it plans on vacating in five years. In this case, the organization might decide to implement projects with a payback period of three years or less and exclude other projects. Managers can make these types of decisions on a case-by-case basis depending on an organization’s economic approach and motivation for improving a building’s efficiency.
If an organization is seeking certification from LEED or the EPA’s Energy Star program, the decision-making process for implementing certain projects might be vastly different than for an organization strictly trying to limit energy use.
It is important to remember organizations will only get out of a building what they put into it. Having an in-depth understanding of the facility will allow managers to implement the proper measures to optimize both time and money.
Commissioning a building or performing an energy audit will help establish a baseline and identify issues – both large and small – that can hinder the performance of HVAC systems. By using energy audits or commissioning, managers can gather and analyze essential performance data to determine which projects or recommendations are best to implement.
Once departments have implemented projects, establishing an extensive preventive maintenance program and performing ongoing commissioning will help facilities operate at a high level. The most important factor in deciding what to do when it comes to energy efficiency is to determine goals for the facility, and from there, target the best methods for achieving those goals.
Gregory Hughel is a mechanical engineer with Facility Engineering Associates — www.feapc.com — a national consulting firm focusing on extending the life of and making improvements to existing facilities.