Mechanical Systems
Veg Out
Landscaping and vegetation around an older building can serve an important function in blocking heat during the summer and harsh winds during the winter.
Old Can Be New Without Being Ugly
HVAC mechanical systems do not have to overwhelm and detract from the character of an older or historic building in order to do their job well.
New Systems Present Challenges
Installing mechanical systems like air conditioning can be challenging for older and historic buildings with high architectural character.
Keep Design in Mind
Most older buildings – even modernist homes – were designed with energy efficiency in mind. In this case, wide overhangs protect against heat gain.
Don't Forget the Simple Things
Simple things like the long-standing tradition of using appropriate awnings can help with energy efficiency and provide a system for controlling heat gain.
What exactly are mechanical systems?
That's a technical-sounding phrase for many of the things that we use every day in our homes and buildings. Some examples of modern mechanical systems include power, lighting, heating, ventilation, air conditioning, fire and smoke detectors, life safety, plumbing, elevators, and sprinkler systems. When upgrading and/or installing these modern mechanical systems in older buildings, preservation architects are tasked with finding ways to fit (and then hide) a tremendous amount of duct work and wiring to actually operate the new systems – none of which were considered for buildings designed prior to World War II. Factor in the need to always protect the bones and historic fabric of a home or building, and this task becomes even more complicated.
However, integrating new systems is not just a matter of finding a place for all of the parts; you must also be mindful of how altering the interior climate will affect the performance of a building's original (and often historic) materials. When 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.
Similar to other weatherization tactics for your home, there is no one-size-fits-all solution for upgrading mechanical systems in your older or historic building. Instead, we recommend a more holistic approach – one that is specific to your home or building, its use, and the needs of its occupants. We also recommend considering a combination of solutions and/or systems. Since we treat each building individually, it might be necessary to think of it as several systems working together, instead of one system meeting all of the requirements of the building's users.
The following frequently asked questions are intended to further explain the passive or "built-in" systems of older and historic homes, as well as the many options that exist for upgrading older structures with modern technology.
Want to dig deeper? Visit our Whole House Resource Bank for links to some of the best weatherization information and materials available online. From insightful blogs and articles by the experts, to checklists and how-to's, you’ll find it all here.
