Crash Course in Efficiency

Community college goes from boiler failure to state-of-the-art in four well-learned lessons

King Tang and Tony Fajarillo (left and center), McKinstry Company, and Greg Angus, mainten-ance supervisor, Shoreline Community College, review mechanical system plans while discussing one of the system's attributes: how the Laars Rheos boilers can be switched from BMS control to its own internal boiler control -- accomplished with the flip of a switch on the cover of the boiler.

Replacing several boiler systems on a tight schedule is not a venture undertaken lightly. But this multi-site project at Shoreline Community College near Seattle quickly won accolades from school adminis-trators, bean counters and maintenance staff alike.

Working with engineers from the headquarters office of McKinstry Company, the school obtained a new system that improves boiler operating efficiency alone by more than 20%. Overall energy improvements are guaranteed to provide more than $80,000 in annual utility savings and to qualify the school for gas and electric utility rebates of nearly $90,000. In addition, the guaranteed annual utility savings will cover the principal and interest on a 10-year low-interest loan from the State of Washington treasurer's office. In the end, only 35% of the project's $1.2 million cost will be funded from the college's capital budget.

"Normally, boilers don't pay for themselves quite so rapidly, because the equipment is expensive," said King Tang, P.E., senior program manager with McKinstry. "But that's not the case at Shoreline. By combining the savings from the utility rebates for boiler upgrades, HVAC controls and lighting and, with the state's low interest energy financing program, Shoreline gets the benefit of many financial advantages. We're now just beginning to make a real impact in the school's energy consumption by replacing some of the many inefficient and malfunctioning mechanical systems."

According to Tang, Shoreline had been using 40% to 45% more energy than the benchmark for colleges in the region. That was the call to action. "There's no question that we're well on our way to improving those numbers," added Tang.

In total, the energy projects will save more than 90,000 therms in natural gas, and 788,000 kWh in electricity every year. Savings on the individual projects are broken out as follows:

Lesson 1: Understanding the problems

Prior to the retrofit, Shoreline was plagued by two key problems: poor system design and a maintenance regimen that became more difficult each year. Shoreline's original systems layout called for 22 boilers to be installed in 13 separate boiler rooms. Add to that an additional 50 HVAC units -- air handlers, condensing units and heat exchangers -- and Shoreline's modest maintenance staff was clearly overwhelmed. Boilers were operated with very low return-water temperatures; this caused acidic condensation and the premature corrosion of many boiler components and flue pipes.

The boilers were also plagued by combustion air problems. Many were housed in rooms too small to access adequately or to install air louvers for ventilation -- a major code deficiency. In many cases, a buildup of leaves and debris in the air intake louvers contributed to an overall problem with incomplete combustion, as well as to flame rollouts, flame impingement conditions and overheating of the rooms. After a complete testing, it was clear that more than 40% of the boilers had completely failed or burned out. In cases where the boilers were still functioning, carbon monoxide levels in some of the boiler rooms were deemed "very unsafe" which, according to Tang, "is an efficiency issue and, of course, a cause of health and safety concern."

"I'm surprised it went on as long as it did without the maintenance staff getting sick," says Brent Irwin, P.E., a senior engineer with McKinstry and the design engineer on the Shoreline project.

Lesson 2: Getting the right people on board

The problems facing Shoreline were not an overnight occurrence -- the hydronic systems' gradual decline continued to worsen during a period of several years. But the need for an overhaul was quickly recognized by several new administrators, including a new vice president, Beverly Jo Brandt, hired from another community college. Among the changes made by Brandt was the hiring of a new facilities director. Having had a similar experience at the college where she previously worked, Brandt had worked successfully with McKinstry and was familiar with the state treasurer's loan program. It quickly became a priority for her at Shoreline.

The close working relationship between McKinstry, manufacturer's rep firm, Columbia Hydronics and boiler manufacturer Laars Heating Systems also was critical in completing the project under tight budget constraints and a compressed time schedule. Final approval of the project was not received until late June, and the new system was required to be operational by the beginning of the new school year - a "window" of only 10 weeks' time.

According to Randy Stegmeier, Shoreline's new director of facilities and capital projects, it was the team approach -- combining the focused efforts of the design/build contractor, the knowledgeable local rep agency and key manufacturers -- that made it possible to complete the job on time. "The multiple project design meetings, full cooperation of everyone involved and routine jobsite visits all played a critical role."

Lesson 3: Being willing to make a change

One of the primary challenges for the project was getting the key players to agree on the boiler selection. Maintenance supervisor Greg Angus wanted to replace the existing boilers with new cast-iron units based on the perception that they would be easier to maintain. The McKinstry team -- after conducting a full analysis of compatible boiler types and suppliers -- recommended the use of a new generation of copper-fin boilers from Laars. McKinstry's findings indicated that the copper-fin boilers would provide the lowest lifecycle cost, while significantly boosting operating efficiency, increasing system capacity and reducing equipment footprint.

Ease of maintenance, however, remained a key concern with Angus. So Columbia Hydronics sales engineer Mike Petterson arranged to take Angus on a factory tour of the manufacturer's facility in California to review the equipment and put his fears to rest.

"That trip really did the trick," Petterson said. "Greg was able to see firsthand how easy it is to get to the heat exchanger. The panel pops off so that you can access the igniter right there. It has warning indicator lights for troubleshooting, and the internal controls also slide out on a tray for easy access to the wiring. With some boilers, you have to disassemble the whole thing to get to the components. Here you don't."

Lesson 4: Not repeating the same mistakes

In the end, Shoreline agreed to install 12 copper-fin, low-NOx boilers. These included 10 stage-fired boilers (two 1,000 mbh, four 750 mbh, and four 500 mbh systems) and two 1,200 mbh fully-modulating boilers -- reducing the total boiler count by nearly half. Because of the stage-fired boilers' fan-assisted, sealed-combustion design, which allows for more efficient fuel combustion, system efficiency was increased to 85%, and to more than 87% with the fully-modulating boilers -- substantially better than the 50% to 60% operating range of the remaining functioning boilers. The ability to stage or modulate individual boilers enables the systems to efficiently meet varying heating system loads. Each boiler room is now equipped with a dedicated boiler system controller to maintain minimum boiler temperatures, to reset temperatures and to fire only the required number of stages, or boilers, to meet the demand.

"The multiple, modulating boiler system concept was a clear design goal from the outset," said Dave Lockhart, Columbia Hydronics sales manager. "Added needs -- requested by the school's maintenance staff -- were to provide the school with controls that governed lead-lag-alternate boiler operation.

"Using these low mass boilers in a primary/secondary system approach is an ideal solution for energy retrofits," added Lockhart. "Rather than maintaining high mass, standby energy at considerable cost, these systems quickly inject incremental energy into system loops on demand. And because of the staged boiler arrangements at Shoreline, the school benefits from several of the most efficient boilers on the market: the off boiler. Yet the standby boiler is fully available and exercised as the alternate lead boiler every 24 hours. For most of the season, system demand is met with just one boiler, frequently with partial gas input. No standby losses and no wasted energy."  

The school's hydronic systems -- in addition to new boiler installations -- were upgraded to primary/secondary loop configurations (from earlier single loops), and each boiler now has its own dedicated pump to maintain constant water flow and consistent temperature, factors that help to extend boiler life expectancy.

The design team also worked closely with local code officials, providing fire dampers, smoke dampers for better fire rating and, where necessary, increasing combustion air inlets to bring the boiler rooms up to code compliance.

"The McKinstry crew did a great job within the confines of some very tight spaces and reused as much of the existing equipment as they could," said Irwin. "They fit the equipment in and still provided adequate maintenance access."

In addition to boiler upgrades, outdated pneumatic HVAC controls were replaced with new direct digital controls for more precise system control and temperature accuracy -- providing major boosts to overall system operating efficiency and the greatest reduction in energy consumption. The boiler controls are also factory-equipped with alternate start/stop and a setback capability to provide additional energy savings.

As part of the college's large-scale efficiency upgrade, mercury vapor lighting in the gymnasium was replaced with high-efficiency T5 lamps and fixtures. Occupancy sensors will also help to reduce energy consumption.

Improved maintenance, of course, will be a major factor in keeping the new systems operating at their best. Columbia Hydronics led Shoreline's mechanical staff through several sessions that focused on boiler and boiler control operation and maintenance. In turning over the systems, just prior to initial commissioning earlier this year, McKinstry also provided a CD with all the mechanical plans and control documents. The McKinstry team also will provide seasonal commissioning and maintenance schedules.

"Every project has its idiosyncrasies," said Tang, "and though this one had its share of challenges, we were all surprised at how smoothly and quickly these installations went. It's what the school was hoping for. Fortunately, we gave them what they were looking for. It was a major success."