Samstag, 4. Dezember 2010

Learning from History (and Archaeology) II - Bronze Age Energy Management

Finds of burnt clay are very common in most prehistoric settlements in central Europe, but they got little attention by researchers. Archaeologist Irene Staeves now analysed burnt clay materials from a rescue excavation at Langenselbold east of Frankfurt in German federal state Hessen. The reconstruction proofs, that Bronze Age technology was meeting modern standards.

Coming from a normal rescue excavation at a Bronze Age settlement all pieces of burnt clay have been analysed for plaster, impressions of wattle, stakes, and other organic materials as cords and grass. It was possible to reconstruct a double framed wall construction of wattle and daub with an infilling made of grass. This insulation layer was probably 10 cm thick.
The 'Hessische Energiesparaktion' an initiative of the federal state of Hessen to enhance energy saving picked up these archaeological reconstruction to calculate the heat transfer coefficient.
Reconstructed bronze age wall: 0,5 - 1,0 W/(m²K)
Medieval to early modern stud wall: 1,6 - 3,2 W/(m²K)
Brick wall (after 1870): 1,5 W/(m²K)
External wall according to Heat Insulation Ordinance 1995: 0,51 W/(m²K)
External wall according to regulation on energy savings 2009: ca. 0,2- 0,35 W/(m²K)

Experimental archaeology proofed a high efficiency of thermal insulation which meets the high standards defined in a Heat Insulation Ordinance from 1995.

Unfortunably the article by Irene Staeves now published in the current volume of Fundberichte aus Hessen does not discuss the wider implications. Hessische Energiesparaktion concludes 'that intuitive action (preventing distress) exceeds human action which is in modern times orientated on money and follows the primate of cost effectiveness'. Though, the bronze age wall of Langenselbold rises the question, how contemporary society can use and implement past ecological strategies. Instead of marveling at past achievments we should think of strategies, how to make use of those archaeological observations and how to integrate them into modern technologies. As circumstances and possibilities have changed we need to ask for an adaptation and integration. Archaeological knowledge on their long-term effects and their social contexts may help going this way. Concerning heat insulation we should ask, how long this simple technology was used and why people abandoned it. It's a myth that past people had higher sense of ecological responsibilty, but they had in some cases experiences of ecological managment which developed over centuries.

● I. Staeves, Wärmedämmung in der Bronzezeit. Hüttenlehm gibt Hinweise auf eine zweischalige Wandkonstruktion mit Grasfüllung. Fundberichte aus Hessen 46/47, 2006/07, 59–106.
● I. Staeves, Wärmedämmung in der Bronzezeit - doppelte Flechtwände mit Grasfüllung. Denkmalpflege & Kulturgeschichte 4/2007, 28–30 (online).