Retro-Commissioning: ‘FUND-RAISING’ THROUGH SYSTEMS MONITORING
I recently attended a black-tie hospital fund-raising dinner where the guest donations totaled about $100,000. During dinner I told a story of how I had just found $200,000 worth of energy savings in three hours at a nearby hospital. One of the dinner guests commented that I had personally “donated” twice as much money to that hospital as the 1,000 guests combined—and in less time than it took for the waitstaff to serve us our (questionable) dinner.
Retro-commissioning (Retro-Cx) is a construction industry trend that has tremendous benefits to building owners, as well as design teams. However, the adoption of Retro-Cx by the healthcare industry has been slow. Healthcare facilities are perfectly positioned for maximum benefits from Retro-Cx because their building systems operate 24/7/365; energy expenditures often approach $4 to 5 per square foot, and facility staffing and maintenance budgets are continually subject to scrutiny.
Retro-Cx's value has been clear to me since I first became involved in it five years ago. As an engineer, I am intimately familiar with the potential impact (positive or negative) caused by simple adjustments in the components of a building's mechanical/electrical systems. The actual Retro-Cx process is relatively simple—the most difficult part is convincing owners and architects that the cost-payback calculations in the Retro-Cx reports are valid. Returns on investment value in excess of 1,000% are difficult for many owners and architects to accept; they seem too good to be true. Yet it is not uncommon to discover, for example, $50,000 worth of hidden energy savings just by sitting in front of the hospital's building automation system computer for two or three hours.
Wasting energy in any facility negatively affects all of us. Higher energy costs can raise the facility's cost of doing business, which is passed on to consumers and/or insurance payers. Avoidable overuse of heating/cooling places a false load on the central plant, which means capital will be unnecessarily allocated to central plant expansion. Moreover, the added energy generated by the utility company for the unnecessary load produces greenhouse gases and environmental pollutants that negatively affect the health of everyone.
In short, it simply costs too much not to Retro-Cx your facility.
Commissioning: New Construction
The complexity of building systems has increased exponentially over the past 20 years. Meanwhile, the architect's/engineer's responsibilities and time on-site have decreased. In addition, the average real wage of contractors has dropped 20%. These factors combine to create a “quality gap.” Owners are receiving buildings that do not work as designed and are consuming more energy than necessary. Building commissioning emerged as a way to fill the gap between the owner's expectation of a perfectly functioning building and the effect of economic pressures on the building design and construction industry.
In new construction, the commissioning firm is responsible to ensure the quality of the design team's documents. It observes the construction to make sure the contractors are building what the owner wants. After the equipment and systems are installed, the commissioning firm then “test-drives” the building to identify hidden problems and fix them before the building is turned over. The result is a building that works properly the day the owner moves in.
Any qualified commissioning firm can provide a surprising list of construction, setup, and operational deficiencies that its inspectors discovered on past projects. Review of these records shows that the resulting operational cost savings generally pay for the commissioning in less than two years.
Based upon the cost-saving results of commissioning, it follows that the same potential cost savings today remain hidden within existing facilities that were not commissioned during initial construction.
Retro-Cx: Existing Facilities
Every department in a hospital is accredited, audited, certified, or inspected except one: the department responsible for ensuring that you can deliver healthcare services 24/7/365. The Facility Management Department is responsible for maintaining the largest capital asset of a hospital facility and has the authority to spend millions of dollars a year with no oversight.
During the past 20 years, the healthcare industry has outsourced or downsized these departments, while at the same time burdening them with new duties, such as security coordination, safety coordination, furniture relocation, holiday decoration, and basically everything but focusing on their core function of monitoring and operating the facility's systems. Staff labor costs have decreased, but owning and operating costs are increasing at a greater rate than the labor savings. The negative cost impact upon the typical healthcare facility is hidden to almost everyone except an experienced commissioning firm.
Retro-Cx of an existing healthcare facility usually results in a heating/cooling energy cost savings of at least 10%—sometimes a lot more. Utility costs for a healthcare facility generally run about $3 to 5 per square foot per year, so a 10% savings could easily equate to $60,000 a year for a 200,000-square-foot facility.
Retro-Cx is performed by a specialist with extensive mechanical/electrical design and field experience. The commissioning expert's primary tool is the building automation system computer, which provides detailed performance and operational data for the entire building. Evaluating the performance data for air-handling units, chillers, boilers, pumps, and other equipment quickly yields insight into potential operational problems.
Retro-Cx is not the same as a maintenance contract or an energy audit. Retro-Cx is a high level of system performance analysis. The Retro-Cx approach to energy savings is also different. It focuses on actual equipment operation performance, not on capital upgrades to equipment. If the building system equipment load can be reduced through optimized temperature, humidity, and pressure settings, then central plant capacity (and energy consumption) can be reduced accordingly.
For an overview of steps toward starting the process, see the table.
The primary energy hogs in a healthcare facility are the air-handling units. They generally have a preheating coil, a cooling coil, and a reheating coil, all sized for the coldest and hottest days of the year. A coil malfunction anytime between the hottest and coldest days of the year is not readily apparent in terms of comfort. A reheating coil can usually overcompensate for a malfunctioning cooling coil to prevent overcooling and vice versa. Because the rooms are usually still comfortable with a malfunctioning coil, the facility staff receives no complaints and is rarely aware that the air-handling unit is consuming up to twice as much energy as it should be. Reducing improper simultaneous heating and cooling of air-handling unit systems produces the bulk of the energy cost savings. (A good analogy of an air-handling unit simultaneously heating and cooling is driving a car with the gas pedal to the floor while controlling the speed by using the brakes.) A typical healthcare air-handling unit can waste approximately $10,000 per year in heating and cooling energy costs of running boilers and chillers in this manner. By reducing the air-handling unit heating and cooling loads, the load on the boilers and chillers in the central plant is reduced by the same amount. Retro-Cx can identify such problems and help get them corrected.
New Construction Capital Reduction
Immediate energy savings. Because Retro-Cx reduces heating and cooling loads, which reduces consumption of energy such as electricity, natural gas, fuel oil, etc., by approximately 10%, this “new money” could be applied toward a new capital construction project or toward upgrading old equipment.
Immediate central plant capacity increase. Because Retro-Cx reduces the load on the central plant equipment, the result is new “spare” capacity. This new spare capacity could be used to reduce the size of the central plant expansion in a new construction project. At about $1,000 per ton installed for chillers, just a few tons of cooling savings could result in pleasant surprises in the new construction budget.
Retro-Cx, in short, puts the value in value engineering. HD
Timothy P. Pennock, PE, QCP, LEED™-Accredited Professional, is Director of Commissioning Services, GRG Consulting Engineers, Inc., with offices in Florida, California, and Nevada.
Four steps to Retro-Commissioning
1. Research Retro-Cx.
Visit http://www.peci.org to learn more about commissioning. Portland Energy Conservation, Inc., has been a leader in promoting the value of commissioning since the early 1990s.
2. Research commissioning firms.
Visit the Building Commissioning Association's Web site at http://www.bcxa.org to research commissioning firms.
3. Select a commissioning firm.
Choose a firm with PEs and controls specialists on staff and experience in healthcare commissioning.
4. Retro-Cx the existing facility.
Review heating/cooling systems’ basis of operation.
Integrate building automation system.
Inspect coils and fans of each air-handling unit.
Report operating deficiencies and energy cost savings.
Maintain energy savings by managing utility bill energy data and annual Retro-Cx. The Retro-Cx results need to be managed by administration so the Facility Management Department does not perceive the deficiencies as a threat. If not, the Retro-Cx effort will get squashed.