Coventry University authorities looking for ways to cut the carbon footprint of the latest building to be added to their expanding campus found that one answer lay literally under their feet.

Underneath the newly opened student centre called The Hub are two 100m deep boreholes that together form a key part of the energy efficient cooling system for the building.

The Ground Source cooling system installed by GI Energy uses only a fraction of the energy of a conventional air conditioning system and has a correspondingly low carbon footprint.

It works by exploiting the natural capacity of the ground to absorb heat, and is making a significant contribution to the university’s plan to reduce its carbon emissions by 35% by 2015.

The Hub is a purpose built student centre with open plan study areas, catering facilities, a doctors’ surgery, careers advice centre and a nightclub that can double up as a 300 seat cinema.

Squeezed into a relatively tight space in the city centre, the three and two storey building has gas central heating, solar hot water, rainwater harvesting and is ventilated with cool air at night automatically. The concrete walls of the open plan study area also absorb heat during the day and radiate it away at night.

Extra cooling is required however, especially for the nightclub and the offices at the front which have sealed windows. The GI Energy cooling system extracts cool water from the ground via one of the 100m boreholes, using it for cooling the building, and returning the warmed water back underground via the second borehole.

The whole installation is monitored every half an hour through equipment placed in a third borehole, which sends automatic alerts if the system needs fine tuning. Readings are sent every month to the Environment Agency which is responsible for regulating and monitoring water extractions.

Lee Hatton, of Coventry University said, “So far we have not encountered any problems, despite the very wet summer. This is our first ground source heat pump installation and already by installing it, we have achieved an excellent BREEAM rating.

“Installing ground source heat pump cooling has also helped us to meet building regulations which, since 2006, have been far stricter about energy efficiency.

“And while having a BREEAM excellent rating confers no financial advantages at the moment, in future it could well affect funding streams.”

Coventry University has a history of embracing new technologies – but that has put it at a disadvantage when it comes to meeting the government’s Carbon Reduction Commitment target by 2020.

No allowance is being made for the fact that it had already implemented major energy saving measures a decade ago, nor for the fact that the campus is expanding. Targets are set for the campus as a whole.

The university is also facing increased bills under the Carbon Reduction Commitment of around £160,000 a year to meet the £12.00 a tonne charge imposed for carbon dioxide emissions annually.

To anticipate future demands for more energy efficient practices, the university is drawing up a campus wide energy strategy for the next 25 years with input from all the major energy suppliers. The use of ground source heat pumps to heat as well as cool buildings will be examined.