Strategy

A conventional HVAC system would have required removing portions of the very historic ceilings, walls and floors to run new duct work. The National Trust recommended The Unico System, which Christman knew only by reputation, because of its longstanding partnership with the organization and its past experience designing systems for historic buildings. Upon exploration, Christman learned that The Unico System’s small ducts could be snaked through existing spaces behind the walls, under the floor and above the ceiling, resulting in minimal impact on the historical fabric of the museum. Unico also offered to donate all of the equipment required for the project. “Unico's generous donation of its services and equipment to this project demonstrates its longstanding support of the National Trust for Historic Preservation,” said Emily Gleason, manager, corporate partnerships business development, National Trust for Historic Preservation.

Christman worked with Unico’s in-house engineering department to develop an early budget for the project, sending floor plans and existing drawings to determine the costs that would be involved. According to Ron Staley, Christman’s senior vice president and director of historic preservation, it was clear that The Unico System would be a more cost-effective option, regardless of the equipment donation. “The biggest savings was that we didn’t have to tear out a lot of walls and then repair them. The Unico System fit economically into the building. Unico’s engineering support group explained how it would work, where we would need to feed the duct work, then worked with the National Trust staff to make it happen,” explained Staley.

Before the renovation, President Lincoln’s Cottage used a steam heating system with radiators (not original to the home) and a few window units for air conditioning. The initial plan was to only install central heating because the home had natural ventilation due to its location on a hilltop and shutter system. However, The Unico System was easily adaptable for both heating and cooling by adding an air conditioning module at the fan end of the system, with no changes to the duct work. Unico’s easily customizable circular outlets were stained to match the original wood floors on the first floor and the walls and ceilings on the second floor. The system is fed by three 5-ton air handlers with chilled water coils that provide both heating and cooling. The air handlers are tucked away in the basement and third-floor servants’ quarters, while the chillers were installed remotely in a historic water tower structure away from the main building.