Drilling of geothermal wells begins
The Steffl Drilling & Pump crew began drilling wells on Tuesday for the geothermal system that will heat and cool the new Wadena-Deer Creek School.
It will take the five-person crew about three months to drill the 200 wells needed to heat and cool the new school's 174,500 square footage. The wells will be 306 feet deep, about 20 feet apart and will be located in the open area west of the school.
Steffl Drilling & Pump crew foreman John Dahl said they typically can drill three wells a day with two drilling trucks. But due to the amount of rock they are hitting, they look to finish two wells a day. Dahl said they are drilling through gravel and rock the first 120 to 140 feet, using several carbide bits with 2,000 pounds of pressure to cut through the rocky layers.
Once the wells are completed this fall, the school grounds will be used again for phy-ed classes and other school related-activities. There will be no visible signs of the wells above ground. A mechanical vault six feet underground will house the mechanical equipment for the well system. Inside the school, another set of computer-operated controls will be housed for the temperature control system.
How a geothermal system works
According to Dahl, just a few feet underground, the earth remains at a nearly constant temperature of 50 to 70 degrees. Working with an underground earth-loop system, a geothermal heating and cooling system utilizes this nearly constant temperature to exchange energy between the school and the earth as needed for heating, cooling, and even hot water heating.
In winter, fluid circulating inside the underground earth-loop system absorbs heat from the earth and carries it to the school where it is compressed to a higher temperature and used to heat classrooms, offices, and make hot water for kitchens and showers. In the summer, the system reverses and expels heat from the building to the cooler earth thanks again to the loop system. The system is so efficient it can be configured to provide hot water at nearly no additional operating cost.
While the geothermal system is expensive to install and equipped initially, WDC Schools will get a fast return and significant savings from the efficiency the heating and cooling system provides. Furthermore, there is less maintenance involved and the system allows the school to free up space for classrooms and less for HVAC equipment. The life expectancy of a geothermal system is about 50 years.
Construction site work continues
Kraus-Anderson Project Supervisor Bill Born said masonry crews will be back this week to do some additional concrete work. He said they are still on schedule for the steel erection to start the first week of August.
"Despite the state shutdown, we are still on track with our construction schedule," Born said.
He also asked that the public stay away from the construction site on the weekends and evenings for safety reasons. During the week days, individuals are to report to the Kraus-Anderson trailer, located on the northeast corner of the construction site. Anyone who goes on the work site is required to wear a hard hat and safety vest, as well as proper clothing and footwear.
"Our main concern is making sure everyone is safe on the site," Born said.