Part 1: Making our new Asheville office more energy efficient

This is the first post in a three-part series detailing energy efficiency upgrades to SACE’s new Asheville office. Read the rest of the series here or watch this video for a virtual tour!

This old house is getting a green makeover!

Since SACE opened our Asheville office in 2003 we have rented office space downtown; first at 29 North Market Street and then in the Self Help Credit Union building on Wall Street. We are proud to announce that we recently purchased a beautiful older building at 46 Orchard Street, just north of downtown for our new Asheville home. Built early in the 20th century as a residential home, the two-story building has been converted into multiple offices. The building presents many opportunities  to improve the energy efficiency, indoor air quality, and longevity of our new space.

SACE is committed to doing all we can at this new space to showcase energy efficiency as the least expensive and most important step in reducing our dependence on high risk energy choices like coal and nuclear. We like to practice what we preach, and our Asheville office is the second of the SACE buildings that we have upgraded – read about the improvement to our Knoxville office here.

When we purchased the property, we knew there would be several large energy upgrade projects that needed to be completed before moving in. Buildings constructed before 1980 are notorious energy hogs, since they were built before modern energy efficiency codes, and often lack adequate insulation and air sealing in the building’s envelope and air handling systems. These are the two biggest areas to save energy in residential and small commercial construction and the two places where we focused most of our energy efficiency upgrades. The first step we took was to hire Green Opportunities, a local organization that provides green job training and job placement services for low-income individuals in the Asheville area. The audit team used diagnostic tools like a blower door test, air blaster test, and visual inspections to pinpoint problem areas and recommend solutions. This post will summarize those findings, and details about the solutions we chose will come in later posts.

An infrared camera reveals that a lack of air sealing around ductwork and air vents allows hot attic air (yellow) to leak to the cooler interior (purple).

Building Envelope

A building’s envelope (the walls, roof, and floors) is usually the biggest source of energy loss; and our Asheville office was no exception. The energy audit team measured air leakage at 1.8 air changes per hour–meaning that every hour almost twice the volume of air in the building escaped through cracks, holes and other leaks! To maintain a comfortable temperature all that air has to be reconditioned and that wastes a lot of energy, and as we all know drafty buildings are uncomfortable to work and live in. We found that the walls were insulated to about an R-value of 12, and there was some (though not nearly enough) insulation in the attic. Attics are some of the most volatile places in buildings, especially during the summer when dark roofs heat up and radiate that heat down in to the building–during our audit the attic temperature was 124 degrees.

The floor between the basement and first floor was completely uninsulated or air sealed. Before we could air seal and add insulation there to define the thermal envelope at the first floor, we would have to address another set of challenges in the basement. Water had been getting into the basement for years due to poor drainage, causing mold and fungus to grow in the duct and wood work. If unaddressed, moisture in the basement could make people working in the building to get sick and degrade wooden structural systems. We decided to take Green Opportunity’s recommendation and fully encapsulate the basement and add new drainage to move water away from the building’s foundation (discussed in greater detail in part three of this series).

Windows

One of the greatest features of our new Asheville home is an abundance of natural light; every office and common space has several windows allowing us to reduce our use of artificial lighting. However, none of the windows had been updated from the original single-paned variety that leak, offer very little insulation from cold or heat, and most had been painted shut, preventing the use of natural ventilation in warmer months. Even though it doesn’t present the quickest return on investment, we decided to replace all of the windows with Energy Star-rated insulated glass windows. Because interior lights will be used so little, at this time we chose not to to replace the existing T-12 fluorescent tube lighting with more efficient lighting; though we might in the future.

The majority of the duct work was insulated, but without proper air sealing conditioned air simply escaped into (and through) the insulation; as evidenced here by dust on the inside of duct insulation.

HVAC Systems

The three air handling systems in the building have between a 80%-90% efficiency so they don’t need to be replaced. However, the duct blaster test showed that the upstairs system leaked 25% and the first floor system leaked about 50%; so much of the conditioned air being put into the system was leaking into the attic or basement. While most of this air leakage came from duct connections that weren’t properly sealed with mastic, some of the duct work was completely disconnected. You might be surprised to learn that our building is not such a unique case, as average duct leakage in the U.S. is around 30%.

Stay tuned for our next two posts that will detail the upgrades to the Asheville office and see the transformation from an old, leaky building to a green showcase!

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