What are Earth Tubes?
Earth Tubes are a passive technology that enable the transfer of ground source energy to heat or cool ventilation air. They are standard concrete tubes that run underground and precondition the temperature of incoming air before it enters the building. They reduce the energy required to heat or cool the building.
How do we use them?
In the summer, the temperature of the ground is cooler than outside air – this keeps the concrete tubes cool, which then cools the air as it passes through and into the building. In the winter, the ground is warmer than the air, meaning that the tubes warm the air as it passes through. Each of our nine earth tubes is a simple pre-fabricated concrete sewer pipe that is 20m in length, buried 3m below ground level.
How do they make us more sustainable?
Earth Tubes can warm winter air by as much as 20°C and cool summer air by 10°C, without requiring energy-consuming mechanical equipment. When combined with heat recovery, they can almost eliminate the need for mechanical air tempering. Earth Tubes are probably the most-effective energy-saving feature of the ERC. They also allow us to use 100% fresh air within the building, without incurring large energy costs as a result.