Warming up to Modular Boilers

Savvy commercial building owners seeing value of modular boilers
By Kristy Alpert, Energy Solutions for Commercial Buildings 2015, pg 10-11

At first glance, the 140-year-old mill in Providence, Rhode Island, seemed like the perfect contender to house The Providence Center, a nonprofit behavioral health care organization. Built in 1875, the solid brick building had been meticulously maintained and preserved by its former tenants, and it looked like very little work would be needed to transform this 72,000-square-foot facility into a 21st century headquarters for the largest community mental health center in Rhode Island.

But, looks can be deceiving. Although the building had won a coveted spot on the prestigious National Historic Register, the renovation team quickly realized the structure wasn't about to win any energy awards in its current state.

"When we moved in, the building was heated by four oil-fired boilers operating beyond their life expectancy at 60 percent efficiency," says Bob Pritchard, director of facilities and projects at The Providence Center, which serves 13,000 clients in 28 facilities. "We were consuming 18,000 gallons of oil on average per heating season. The boilers were 40 years old and had become a challenge to maintain due to their age and availability of parts."

Pritchard and his team knew they needed to make a change. But with so much history at stake, they wanted to make sure the new system wouldn't take away from the building's architectural beauty or structure.

With energy savings in mind, the team turned to Victory Heating, Air Conditioning and Plumbing to design a new minimally invasive, multi-zone system. The goals for the project were to replace the failing equipment, modify the system to allow better climate control in all areas of the building, reduce the facility's energy expenses by converting to natural gas, and decrease the building's carbon footprint.

To fulfill their objective, Victory and Pritchard's renovation teams decided to install an Emerson Swan-manufactured modular boiler system with a 94 percent efficiency rating.

"We are very happy with the performance and reliability of this technology, and the design, installation, and operation of the system have been seamless and trouble-free," says Pritchard.

He says the organization is on track with a 4.8 percent return on investment, saving $60,000 per year in energy costs.

"Since the installation of the modular boilers, we have been better able to control the temperature in the building by using a multi-zone approach instead of one single-zone design of the old system," Pritchard says. "This has helped to alleviate the challenges of evenly heating an old four-story mill building with a poor envelope. We now have a reliable system that allows us to control when and how the system operates, even from satellite locations. The system communicates issues via email to staff allowing us to respond to a no-heat condition that could result in pipe freeze-ups and subsequent damage to the building."

It boils down to...

Modular boilers consist of a series of smaller boilers working in tandem with one another that are then operated as a single-boiler system by one master controller to provide varying amounts of steam. The concept of the modular boiler was conceived not only to confront the issue of space, but also to add value to a boiler that can now operate at peak effectiveness and efficiency.

As the steam requirements of the facility rise and fall rapidly, the modular boiler system quickly turns on and off to eliminate wasteful energy and water consumption. These systems also reduce harmful emissions because boilers are not running unnecessarily. And, since each section (or module) has its own burner that works independently of the other sections, modular boilers are able to operate with oil, gas or propane interchangeably.

"Over the years, technology has moved from large, single boilers with very imprecise load matching capabilities to multiple, smaller boilers operating as one steam system that match the precise steam requirements," explains Doug MacMaster, vice president of U.S. operations, Miura America Company Ltd., the largest boiler manufacturer in the world and a leader in technological advancements in smart boiler technology. "Better communication systems, remote monitoring through the Internet and phone lines also allow for reduced labor dollars onsite as the service providers can keep an eye on the equipment and can recognize operational needs remotely."

The technology has come a long way over the years, boasting smarter controls, and more efficient burners and boilers. The benefits have only increased with the new developments and greater applications in commercial buildings. Benefits for commercial applications include:

  • Improved efficiency. With a modular system, four 200BHP [(total 800BHP) boiler horsepower] boilers can provide enough steam even when one boiler is offline for maintenance
  • Smaller footprint. Modular boilers can be installed where traditional boilers cannot, due to size and weight. The systems and number of boilers can be designed and installed based on the precise needs of the customer, with no unnecessary oversizing to allow for redundant backup systems.
  • Lower utility costs. On average, customers save up to 20 percent on energy costs with these systems and can generate the same amount of BPH in 50 percent to 60 percent of the space of competing systems.
  • Longer equipment life. With a modular system, each section can be rotated throughout the year during periods of medium- to low-loads, greatly reducing the wear on each section while allowing maintenance staff to perform maintenance without shutting down the entire system.
  • Ease of maintenance. Modular boiler designs have been referred to as "plug-and-play systems" due to the ease of maintenance and self-diagnostic controls.

Modular boilers in the office

Modular boilers are an ideal application for commercial buildings, especially in terms of maintenance, comfort control and energy savings. Savvy commercial building owners are taking advantage of the more intelligent controls that are available today with these systems, and even using those controls to determine the building heating load and decide how many modules are needed to meet the building load.

"Each section of the modular system is typically integrated into the building's building management system (BMS)," explains Peter Grealish, senior representative of channel sales, National Grid, the largest distributor of natural gas in the northeast United States, serving about 3.6 million customers in New York, Massachusetts and Rhode Island. "The BMS monitors and controls the need for heat throughout the building. On a demand for heat, the BMS will determine how many sections of the modular system are needed. This is determined by the monitored outdoor air temperature and the amount of load the building is calling for. A commercial energy customer should be installing these types of systems to take advantage of the energy savings that can be achieved."

And, with many local utility companies offering financial incentives for installing these highly efficient and effective systems, the time may be right for more commercial building owners to warm up to modular boilers.