SSAB’s steel piles are also used as an energy source
SSAB’s steel piles have been utilized in Finland as part of an energy piling system. The energy piling system is a Finnish-made ground heat solution developed and marketed by Cool Factory (www.coolfactory.fi), which uses steel piling as a source of ground heat. “At best, the energy piles are capable of producing 30 watts per piling meter. It is possible to install a geothermal heating system with energy piles for all sizes of applications and for all foundations based on steel piles. All RR® and RD® piles are suitable for energy piles up from the RR/RD 90 piles. There is no need to make any significant changes to the piling or foundation plan because of the energy pile system. The foundation also does not limit the use of energy piles as a source of ground heat,” says Tomi Järvinen of Cool Factory Oy.
Case: Detached house @ Suutarila, Helsinki
22 steel piles with an average depth of 18 meters were activated at a property in Suutarila. A total of 350 pile meters were activated for geothermal use. A total of 8kW of peak power output is available from the energy pile system. At this property, energy piles can generate 21,000 kilowatt-hours of ground heat per year.
Who installed the steel piles in your house? How did it go?
The steel piles were installed by Teräspaalutus Tamminen and it went better than in “Strömsö”.
Why did you choose energy piles? What other systems did you consider? Did you compare prices?
The drill well and the air-water heat pump were alternatives to energy piles, but we got a tip from our architect that energy piles could be a good solution for us. I also made a cost comparison, and the drill well or the air-water heat pump would not have been much cheaper. The decision between the drill well and the energy piles was finally formed after hearing one of the nearby older houses dropped 20-30 centimeters from the corners while doing the drill well. The clay was somehow disturbed by the drilling. And there are other houses right next to this one, so I did not want to take that risk.
How have the energy piles affected other construction work?
Firstly, it was agreed, when the energy piles would be made. When they were installed, the next day the piles were concreted and left with a “tiny mustache”, from which the collectors later went into a technical state. The energy piles did not interfere with other construction in any way.
How has the energy collection system installation been going?
Very well. The tubes were brought from the bottom plate through a hollow core with a finished opening. The isolation of the collector tubes and the extension of the tubes took the most time, but that was only for a couple of days. The system is already working well, the efficiency has been about 4 (Seasonal Coefficient of Performance), which is really good at this point. We have not yet connected the heat resistance of the ground heat pump, so at this point the house is already warmed by ground heat, cleanly. At present, the usage rate is less than 10 %, as ventilation is not yet active and warm water is not used.
Who do you think would find the energy piles a good fit?
Anyone who thinks about taking advantage of geothermal heat – or why not for those who don’t yet think about geothermal heat. There is no need to drill at all in this solution. Energy piles are a wise choice, especially if you are piling anyway, so why not use steel piling at the same time as a ground heat source. The splitter can also be installed, for example, on an intermediate floor, so it does not even take up the interior space.