piles, the energy piles have an inlet and outlet section in the
top of the pile. Inside the pile, the PE tubes run down in a
“single-u” configuration, allowing liquid to flow from the inlet
section down into the pile and up to and out of the outlet section.
The PE tubes are pressure tested with arc welding, which
fuses two pieces of a workpiece together by using electrodes.
The same welding method is used when connecting the
energy pile to tubes outside of the pile.
Installation is similar to standard piles, although
Henriksen points out that it’s important to be extra careful
on the building site to avoid damaging the piles or the inoutlet
tubes once the piles are installed. “After ramming the
energy piles into the ground, it is necessary to connect the
piles to a heat pump through a series of tubes,” he said.
Although energy piles require a significant capital cost
investment, the low operational costs can result in a positive
return on investment over time. “It is possible to achieve
pay-back periods downwards of five to seven years in ideal
thermal soil conditions and with the right system setup,”
What are the advantages of energy piles?
Energy piles make use of shallow geothermal energy. This
is the energy provided to the ground by the sun, reaching a
depth of 0.5 to 20 metres. This is not to be confused with more
traditional geothermal energy which comes from the core of
the earth further down.
In the seven to 18 metres that energy piles are placed, the
temperature of the ground is constant all year at temperatures
ranging between 8°C to 10°C. There is limited fluctuation in
the available energy source to supply a building’s energy
demands compared with the upper layers of the ground that
are subject to the changing seasons.
The advantage of using energy piles is their efficiency in
establishing a ground source heat exchange system by combining
heat exchangers with the foundation of the building in a twoin
one solution. This is especially advantageous for buildings
Cherry Street Stormwater and Lakefilling Project
The Port Lands, Toronto
120 years of deep
Design build solutions
26 Q4 2019 www.pilingcanada.ca