Living Green

Green success lauded at Princeton Academy

By Stephanie Vaccaro
   Princeton Academy of the Sacred Heart has prioritized sustainability since its inception 13 years ago. The school was recently recognized by Sustainable Princeton with a leadership award for the completion of its geothermal wells.
   ”We are a young school, but part of our mission is to be good stewards of the earth,” said founding headmaster Olen Kalkus. “So, we’ve always looked for ways that we can be more green, more sustainable.”
   The school, housed in what was once a convent, was in need of renovation. So, when officials surveyed their options, they came upon the possibility of heating their school via geothermal wells. Although the initial cost is high, roughly $500,000 more than traditional options, calculations showed that the school would recoup that money in savings on electrical costs over the course of 10 years. And, as a plus, the system provided the school with air conditioning for the first time.
   Geothermal wells, in this instance, involved digging 450 feet into the ground, where there is a constant temperature of about 57 degrees. But because of the school’s location on the Princeton Ridge, contractors were not drilling into the soft earth, they were drilling into stone. So, while the company that installed the wells said it should last at least 20 years Mr. Kalkus expects the school will see a much longer life.
How geothermal works
   The geothermal system is based on heat transfer.
   ”In many ways it works like a refrigerator,” Mr. Kalkus said. “You have those coils on the back of your refrigerator and in the summer they get particularly warm. They’re transferring heat from inside the refrigerator to the outside and that cools your refrigerator, and the inverse happens bringing heat in.
   ”Essentially, we have this liquid that’s environmentally safe, much like the antifreeze that you would put in your car radiator. It flows through these 40 wells that are 450 feet deep down in the earth where the temperature is about a constant 57 degrees. So, this liquid then comes up and it connects to our geothermal system, which is water being piped through the school and basically transfers that 57 degrees into the building, and then the fans blow it to circulate it.”
   The geothermal system helps reduce energy use, Mr. Kalkus said. “All we’re really doing is running some pumps to circulate the water and then some fans. So, the electrical footprint is much lower.”
   ”In the winter it’s sort of the reverse,” Mr. Kalkus said. “Instead of cooling the outside air and finding a way to blow the heat through the buildings, now the water comes up at 57 degrees and a little bit more energy is used to compress that so it brings the water to a hotter temperature and then it flows through our system, and again the fans blow out the warm air.
   ”So, we’re using a bit more electricity, but it really cut down on our gas heating, which is what we had here before,” Mr. Kalkus said. “The advantage to that is that we cut our carbon footprint significantly.”
Other sustainable measures
   This project is one of a number of steps the school has taken to translate its belief in being good stewards of the earth into action. Other steps include installing water fountains that are designed to refill reusable bottles.
   ”What’s a little bit different about the ones we brought in is there’s actually a counter,” Mr. Kalkus said. Her explained that the process allows users to keep track of how many bottles aren’t ending up in landfills. “That was important because feedback changes behavior. We saw right away that our boys were noticing that.”
   Boys at the water fountain made comments to one another about talking to their mothers about not giving them anymore juice boxes.
   When it came to designing the new gym, the school opted for a passive design, meaning that the gym was built into the earth, which helps maintain a constant temperature. It was also designed with an unevenly pitched roof, south-facing, that will lend itself to maximizing the power of the sun when solar panels are installed.
   The school also installed lights that have motion detectors, so they shut off after 10 minutes of inactivity, and daylight sensors that adjust the brightness of the lights based on the amount of ambient daylight.
   And when it came to deciding on how much of the land needed to be paved for parking, the school opted for a smaller amount with the understanding that visitors could simply park on the grass for the occasional large event.