Leadership in Energy and Environmental Design (LEED) is the building-rating system conceived and introduced by the U.S. Green Building Council (USGBC) in 1999. LEED uses a holistic system to quantify and measure the performance of a building as it relates to five key areas: sustainable site development, water savings, energy efficiency, materials selection, and indoor environmental quality. USGBC chose these areas because they provide a way for us to obtain a broad perspective of how a building will affect our communities — from how it affects the humans occupying it to how it affects the environment in which it is constructed and occupied.
Why should we, as hvac/mechanical contractors, care about the LEED approach to construction? First, because we are the professionals responsible for installing, commissioning, maintaining, and sometimes designing systems for two of the five LEED areas (energy and atmosphere; and indoor environmental quality) within buildings. Second, professional consulting service providers, such as architects and engineers, are already offering these services to our customers. It is time, for us as hvac/mechanical contractors, to become familiar with the LEED process, with commissioning requirements, and if necessary, become accredited LEED professionals and certified commissioning authorities. If we don’t, we’ll find our customers being served by other firms in this area.
Impact on Our Communities
The buildings we construct and operate consume 30% of the total energy (electricity and fossil fuels) as well as 60% of the generated electricity in the United States. They consume 5 billion gallons, annually, of potable water simply to flush toilets. They also create 2.5 pounds of solid waste per square foot. It’s not hard to see why it’s important that we take a broader view of the buildings we construct and their impact on our communities.
Research has shown buildings constructed using the LEED approach create environments that result in lower absenteeism, improved work quality, up to a 16% increase in employee productivity, less solid waste, and improved local economies; and are healthier places to work and live. How different would the development and construction process be if building owners and managers understood the “total” impact of their decisions when constructing and operating their facilities? Would they be willing to spend slightly more if they knew of the above benefits? Lower absenteeism, improved work quality, and increased employee productivity are goals every company would like to achieve. Now it’s possible simply by employing the LEED process.
The LEED system uses a points-based process to determine the level of success the building will and has achieved during its construction or renovation process. The largest number of points can be achieved via the energy and atmosphere category. This is where hvac contractors can and should have the largest impact.
Each of the five areas of the LEED rating system have prerequisites that must be met prior to earning any additional points. For energy and atmosphere, these prerequisites are commissioning, minimum energy performance, and refrigerant management.
In order to meet the prerequisites, a commissioning authority must be part of the design/construction team and an independent third party, except for buildings with less than 50,000 square feet. The authority must commission energy-related systems including hvacr and associated controls; lighting and associated controls; domestic hot water; and renewable energy systems. Research has shown the median cost to commission an existing building is 27 cents per square foot with average energy savings of 15% and paybacks of 8.5 months. For new construction commissioning, cost typically is 0.6% of total construction costs (about $1 per square foot) of the project with a payback of 4.8 years.
The Case For Commissioning
A study by the Lawrence Berkley National Laboratory found an average of 11 deficiencies per building for existing buildings and 28 deficiencies per buildings for newly constructed buildings; and the majority of the deficiencies were directly related to the hvac systems. The majority of these were directly associated with the air-distribution system. In the buildings studied, corrective measures where focused on building operation and control systems.
Buildings with less than 50,000 square feet represent the majority of buildings in the United States and therefore don’t require a commissioning authority to be an independent third party within the LEED process. This provides a unique opportunity for the hvac/mechanical contractor to bring substantial value to the design/construction team and profitability to their business.
Consider an existing 20,000-square-foot building with rooftop equipment for its hvac system; where the building owners also operate a business employing 100 people earning an average salary of $45,000 and with operating expenses of $2 per square foot annually. The business is experiencing absenteeism rates of 3% of total annual employee salaries.
The hvac contractor proposes to the building owners that they should retro-commission their building for a cost of $6,000 (30 cents per square foot). During retro-commissioning, the hvac contractor finds the rooftop equipment is delivering 70% of the design airflow (total and outdoor) to the spaces. As part of the retro-commissioning, the system is rebalanced to meet the original design intent for total and outdoor air.
After six months, the owners discover that the absenteeism rate has dropped to 1.5% of total hours annually, and operating expenses have Going Greenbeen reduced by 15%. Cutting the absenteeism rate by 50% represents $67,500. This alone would be a great reason for a company owner to decide to retro-commission its building. A 15% drop in operating expenses, represents $6,000, a one-year payback on the cost to retro-commission the building.
With this simple commissioning example, it’s easy to see how an hvac/mechanical contractor can provide valuable, professional services in the area of commissioning. We are the professionals with the most intimate and in-depth knowledge of these systems. We are the ones who install them, in some cases design them, and in many instances maintain them. We simply need to begin to educate our building owners/managers, who are our customers, about the advantages of commissioning or retro-commissioning their buildings. We shouldn’t let the architects and engineers become the dominant players in this market area. While these professionals are necessary team members, ultimately it is our responsibility to ensure the hvac and indoor environmental systems are properly installed, operated, and maintained. We not only design and install these systems, but we turn the wrenches and other tools that ensure these systems are maintained and operated properly. If we don’t step in to fill the need for commissioning services, we’ll find our customers being served by other firms, and once again we’ll simply be the hands that turn the wrenches or change the filters.
Ellis G. Guiles Jr. is Vice President, TAG Mechanical Systems Inc., and author of "LEED, Follow or Get Out of the Way". He is a Licensed Professional Engineer in the state of New York, a Residential Energy Services Network Home Energy Rater, Building Analyst, and Heating Specialist. Additional certifications include P.E., M.B.A., HERS Rater, and BPI Certified (Shell, Heating, AC/Heat Pump).
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