Ground-air Heat Exchanger


AWADUKT Thermo is a ground-air heat exchanger system, also known as earth tubes, for pre-tempering ventilation air. Ventilation air is drawn through underground pipes buried at a depth of 1.5m, which pre-cools the air in the summer and pre-heats it in winter, using the near constant temperature of the ground (7-13°C).

The system has been extensively used across the UK in domestic and commercial projects. The system is ideally linked up with a mechanical ventilation unit with heat recovery (MVHR) to offer a full ventilation solution.


  • Low energy cooling system for buildings built to zero carbon / PassivHaus standards
  • Antimicrobial silver inner layer to prevent microbial growth inside the pipes
  • Thermally optimised polypropylene material for improved heat transfer
  • Coefficient of performance up to 50 for residential applications
  • Bespoke REHAU design software to estimate energy savings for each individual project
  • Complete system from air inlet tower to condensation chambers and wall seals
  • RIBA/CIBSE approved CPD available on request


Fresh Air with AWADUKT Thermo