Weil-McLain SlimFit

The University of Virginia sought a way to quickly provide temporary heat during construction projects while also reducing boiler rental expenses. The solution was the development of two innovative mobile boiler trailers that provide on demand heat where it’s needed.

The University of Virginia is a public research university in Charlottesville, Va., founded in 1819 by Thomas Jefferson. It is the flagship university of Virginia and home to the Academical Village, a UNESCO World Heritage Site.

Like many large, historic universities across the country, especially in the Midwest and Northeast, the University of Virginia utilizes central steam heating plants that pipe steam and heating water to campus buildings.

The university is in the second year of a five-year project to convert its steam systems to low temperature hot water for more efficient heating across the grounds.

“During a pipe or heat exchanger replacement, we would typically rent boilers to heat the affected buildings,” said Cameron Ratliff, associate director of utilities distribution with the University of Virginia. “However, boiler rental costs were expensive, and so we were looking for a more cost-effective solution for temporary heat.”

The university team came up with an innovative idea: build its own custom mobile boiler trailer.

Building the Trailers

Collaborating with Ferguson Plumbing Supply, its main supplier for pipes and fittings, and SE Burks, an HVAC solutions and equipment company, the university facilities team came up with the idea to develop a mobile heating system using a 7½  x 20 ft. trailer and an 8½ x 24 ft. trailer as the housing. The team selected four Weil-McLain boilers to serve as the heart of each system.

“We developed our first mobile heating trailer with four Weil-McLain Ultra boilers for a total output of 1.2 million BTUs to provide temporary heat if a building’s heating went down,” said Ratliff.

The Weil-McLain Ultra boiler is designed to operate in low temperature condensing applications and features a coated cast aluminum heat exchanger, up to 94% AFUE efficiency and high- grade stainless steel burner with quiet operation. In addition to the boilers, the trailer was outfitted with connections for fuel, water and electricity.

It didn’t take long for the University of Virginia to put the mobile boiler trailer into action.

“Carruthers Hall lost its boilers during the winter, and we had our 1.2 million BTU trailer connected in one day to provide temporary heat while we serviced the boilers,” said Ratliff.

With the success of the first trailer, the University was determined to build a second mobile heating trailer with even more heating capacity.

“The design for our second trailer required a powerful, efficient boiler that could meet our target BTUs while also fitting in an 8½ x 24 ft. trailer,” said Ratliff. “I researched the Weil-McLain SlimFit unit, and it seemed perfect for the application. We chose the 750K BTU SlimFit models as they were the largest units we could fit and because they operate on either propane or natural gas.”

Wes Collings from SE Burks offered guidance on selecting the boilers, and the facilities department teams installed the boilers.

“The SlimFit was an ideal choice for the small footprint of these trailers and because of the unit’s easy serviceability,” said Collings. “The university included extra pipe connections so two more units can be added to increase the capacity even more.”

The SlimFit boiler’s narrow housing enhances maneuverability for confined spaces and weight restricted areas. The design also increases usability and access for installing contractors, consulting engineers and facility managers for commercial retrofit projects.

With the four SlimFit units installed, the University now has a second boiler trailer with a total heating capacity of 3 million BTUs with the option to add two more boilers to increase  it to 4.5 million BTUs if needed, for larger heating season applications.

As the university transitions from steam heat, the facilities team also is creating temporary connections for easy connectivity to the trailers.

“We are removing heat exchangers and inserting blending loops with PICV valves and temperature regulators, so all of our buildings are directly connected to the plants,” said Ratliff. “Should we have an emergency breakdown, we can simply pull up the trailer and it’s plug and play.”

Temporary Heating on Demand

“We now can heat the majority of our facilities on grounds at any time with these trailers without having to rent boilers,” said Ratliff. “Waiting for a rental boiler is not an ideal option during the heating season when these systems are in peak demand.”

Ratfliff also notes that the small size of the trailers is advantageous, too.

“The trailers are easy to move around the grounds,” he said.

Besides having on-demand heat as needed, the university is experiencing significant expense savings from expensive boiler rentals.

“Our University CFO is not only intrigued by these trailers but also quite thrilled with the cost savings,” Ratilff added.

Ratliff noted it was a team effort to design the mobile heating systems.

“We really enjoyed putting out heads together to build these trailers,” he said. “It really is the perfect application for our university; the cost savings alone make it so worth it.”