Asset International Ltd. (Asset), the leading manufacturer of Weholite HDPE plastic sustainable drainage and water management products, has recently entered the ecological heating and cooling sector, and one of its first projects was to supply a bespoke header pipe work system for a ground air heat exchanger at the new Giant’s Causeway Visitors Centre in Antrim, Northern Ireland.
The award winning building, which is owned by the National Trust and was designed by Dublin based architects, Henehan Peng, cost £18.5 million to build and took 18 months to complete.
Central to the philosophy behind the design was the issue of ecology and sustainability and the entire complex was designed with this ethos in mind. This is perhaps best represented by the aesthetics of the building, which is hidden from the coastal landscape by a grass roof.
To underline the success of the project, the Visitors Centre has already achieved a BREEAM ‘Excellent’ award, which mea¬sures overall sustainability in design, materials, energy, construction management and ecology. Something which Asset International, a CEMARS (Certified Emissions Measurement And Reduction Scheme) accredited firm is proud to be a part of.
Crucial to the BREEAM status was the heating system utilised within the centre, which operates a REHAU designed ground-air heat exchanger system; an innovative zero carbon method of heating and cooling a building. The system (also known as ‘earth tubes’) draws air through underground Weholite pipes at a depth of 1.5 metres, which pre-cools the air in the summer and pre-heats it in winter, using the near constant temperature of the ground (7-12°C).
Asset International supplied 125 metres of 1050mm diameter Weholite pipe work to REHAU for use in the ground-air heat exchanger system. Weholite is being used as the main header pipe within the REHAU air heat exchanger system. The header pipes carry air to and from the patented heat transfer pipes into the base of the visitors centre. It also acts as a conduit for all of the condensation produced in the damp winter months.
Asset International Ltd also provided all of the air-tight access shafts to complete the system. The shafts provide an access point for maintenance, as well as housing the sumps and pumps that remove the condensed water created in the system.
The unique design of Weholite pipes made it the perfect choice for this ecologically focused project. Weholite is a structured wall product, which means that there is an air barrier between the inner and outer wall of the pipe. This barrier reduces the thermal co-efficiency of the pipe, meaning that once the air has passed through the heat transfer pipes the Weholite header pipe minimises the residual energy loss until it reaches the main building.
Steve Richmond, Business Team Manager for Renewable Energy at REHAU, commented: “Due to the bespoke nature of a ground-air heat exchanger system, it is important that the header pipe and access chambers are fabricated to a high standard to ensure optimum performance. Working with a UK fabricator such as Asset, we could liaise closely together on the final fabrication design. The Weholite pipe matches the requirements for a ground-air heat exchanger header pipe to compliment our unique AWADUKT Thermo antimicrobial pipework.”
Technical engineer at Asset, Paul O’Regan, added: “Weholite lends itself to underground air duct systems such as the one installed at the Giant’s Causeway Visitors Centre, due to its versatility and ability to be fabricated easily into complex arrangements. This is a key attribute when the air duct has to navigate around a multitude of other services that need to be installed below ground.
“An added bonus is that we were able to assemble and test pre-fabricated sections at our factory in Newport, South Wales, minimising the installation time on site and increasing the confidence of the customer.”
