In 2009 CxGBS® was contracted to provide retro-commissioning services and provide recommendations for a historical building in downtown Charleston, SC. The building was beautiful and designed with the highest quality in mind when they were first constructed, but was now tasked to lower energy use. During my first visit to do an assessment and investigation of the building’s operation and overall energy efficiency, I began by interviewing the building operations manager. He was a retired military mechanic that was somewhat ornery, but friendly just the same. Having worked in the military, he was very knowledgeable in all things mechanical and comfortable operating the recently updated Building Automation System. During our interview, he told us about the steps made to make the building more energy efficient, such as adding demand based ventilation and replacing their old chiller with a state of the art chiller. We then moved on to the issues that he observed in his day to day operations. The overwhelming problem that he encountered was high humidity in the building. It was due to the high humidity that he ran the building’s HVAC system 24 hours a day, and still had trouble keeping the humidity down. With the building located so close to the coast, he said that the moisture would come through the walls and raise the humidity if he turned the HVAC system off at night.
He then directed me to all of the drawings and documents. After thoroughly reviewing all of the building information, we proceeded to each major piece of equipment to observe their operation. The majority of the building was served by a giant air handler filling an entire room. When we climbed up to the room that held this massive air handler, I noticed that an injection fan, which was also in the room, was not running. When asked why the fan was not running, the building manager said that the fan was ordered to be turned off by a company engineer, in an effort to save energy. Everything began to make sense. That fan that was turned off was responsible for supplying all of the ventilation air to the building. As a result of the fan not running, the building was now negatively pressurized. Rather than conditioning outside air by controlling its path into the building, humid outside air was infiltrating through doors and window cracks.
The moral of the story: training and documentation are keys to maintaining a building. In this case, as operations staff had turned over, the correct operation of the building was lost and resulted in a severe humidity problem.
May 19, 2011 Press Release
Jay Enck will be speaking at the USGBC Sustain SC event in Columbia, SC June 3rd at 10:30 AM about “Sustainable Design Guidance.” More info and registration at http://www.usgbcsc.org/site/?cat=21