A thermal labyrinth decouples thermal mass from the occupied space, usually by creating a high thermal mass concrete undercroft with a large surface area. Decoupling the thermal mass means it can be cooled to a lower temperature than if it was in the occupied space.
This stored ‘coolth’ can be used to condition the space in hot periods.
The labyrinth layout needs to balance optimum thermal storage with the air resistance of the system. Creating air turbulence, by increasing the roughness and incorporating bends, improves heat transfer. However, incorporating too many bends may increase the air resistance beyond the point where the system can be part of a passive or naturally ventilated scheme.
 Size and output
As labyrinths are often constructed directly beneath a building, only the sides and floor of the labyrinth are in contact with the earth and the top of the labyrinth is directly coupled with the building. This means that the labyrinth needs to be well insulated from the building to prevent heat transfer.
The earth contact of the labyrinth gives the benefit of steady ground temperatures, however, the undisturbed ground temperature cannot be used in calculations, as it will be affected by the presence of the building and the operation of the labyrinth. This means that optimisation of the design requires a complete thermal simulation of the system.
 Running costs
Regular inspection and cleaning of the labyrinth are recommended, although thermal labyrinths are generally virtually maintenance free. The major cost that can be incurred is when fan power is required to supply air through the labyrinth.
Thermal labyrinths can be integrated into a building's structure to provide free cooling in the summer and pre-heating of air in the winter. They can have high capital costs, but over the life of a building,
can yield substantial savings by reducing peak demand for cooling and heating.
This article was created by --Buro Happold, 17 March 2013, based on a 2008 article in 'Patterns'.
 Related articles on Designing Buildings Wiki
- Air source heat pumps.
- Dynamic thermal modelling of closed loop geothermal heat pump systems.
- Earth-to-air heat exchangers.
- Geothermal energy.
- Geothermal pile foundations.
- Ground energy options.
- Ground pre-conditioning of supply air.
- Ground source heat pumps.
- Thermal mass.
- Trombe wall.
 External references
- Ingenia, Going underground September 2006.
Featured articles and news
3 ways the world’s fastest growing economies can close the infrastructure gap.
The sooner early warning notices can be appreciated as of mutual benefit rather than one-sided advantage, the better.
BSRIA responds to government green storage announcement.
What is phenomenology and how does it relate to the built environment?
Read about Belgrade's Brutalist landmark - the Western City Gate.
Read about the measures that can be taken by individuals to protect and minimise exposure to outdoor sourced air pollution.
Government announces leaseholds on new-build houses will be banned.
Transport Secretary announces public consultation into London's funding of Crossrail 2.
Have a look at some of the most impressive concert stage designs of all time, including Pink Floyd, U2, Rolling Stones, and more...
What is the Home Quality Mark? Find out how it can help you when buying/renting a new home.
Business Secretary launches £246m Faraday Challenge to establish UK as world leader in battery technology.
Government announces new plans for regulations to improve safety and security awareness of drone users.
Read our introductory article to the various different types of fuel.