Retrofit 'Green' : Mechanical Systems

Power, lighting, heating, ventilation, air conditioning, fire and smoke
detectors, life safety, plumbing, elevators, sprinkler systems . . .

"Older and historic buildings without modern mechanical systems were designed with human comfort in mind, relying on building features operated by the occupant to keep the environment comfortable. The difficulties begin to occur when a modern mechanical system is introduced. Suddenly, the passive mode becomes underutilized, relying totally on an active, energy guzzling system. There is no one-size- fits-all solution for upgrading systems. We recommend a more holistic approach –one that is specific to your home or building." - The National Park Service

Mechanical systems prove to be the greatest challenge in updating historic buildings. Architects are challenged to find creative ways to include these systems, without damaging the historic fabric. Extensive ductwork and wiring makes this particularly difficult. All historic buildings are unique and changing or upgrading mechanical systems often requires an extensive amount of work, so we suggest doing your homework before committing to any change.

First: Learn your house. If looking to update your HVAC system, first, turn it off. Historic homes were built as a reflection of their region and climate Pinpoint the features of your home that assist in improving the comfort of your home. How can you maximize natural breezes and ventilation to assist with your cooling load? In Charleston, porches or piazzas can have an enormous impact. Test out the existing features of your house!

Second: When investigating new systems, examine your house. Look for spaces and places to put all of the parts that the mechanical system requires. Can the tanks go in the basement? How will you run wiring, piping or ductwork to different levels and rooms of the house, without damaging existing historic fabric?

Third: Consider how a new system will affect the interior climate of your home. "The differential between inside and outside temperature is altered greatly, the risk of damage also improves greatly. Too much or too little humidity can have adverse effects on structural as well as decorative elements, rotting wood, dampening insulating, and corroding metal components."

"At the core of the issue of retrofitting historic buildings with upgraded mechanical systems is human comfort and health. It is not an unreasonable expectation that we should feel comfortable with the air temperature and quality in our homes, especially when technology exists to make this possible. Furthermore, mechanical codes establish minimum requirements for fresh air, comfort conditions, and energy efficiency. In older and historic buildings, one aspect of rehabilitation projects for energy efficiency and improved performance (as well as comfort) is understanding how the building was intended to function with operable windows and other passive ventilation systems."

- The National Trust for Historic Preservation


Mechanical Systems Links and Resources

Are there options for heating and cooling an older home?

My home is cold in the winter and hot in the summer. What do I do?