(University Innsbruck, Austria)
Calculations and thoughts about construction, performance and function
Research project funded by university Innsbruck
Archaeological literature praises comfort, simple operation mode and construction of hypokaust. Excepting the fact that there isn’t “ONE hypokaust”, but rather countless variations, operation of reconstructed equipment showed that it isn’t as simple and unproblematical as assumed: none of these equipments is functioning as assumed.
I consider the hypokaust heating system from archaeological and engineering sight with the goal to better understand the system through coaction of its parts.
Additionally to own job-related heating engineering experience, I had assistance of three research centres and of development division of a boiler manufacturer. Experiences of operators of reconstructed hypokausts also influenced this project. For better comparison I used modern technical engineer standards as bench marks whenever possible.
- First time the heating load of 11 reconstructed roman buildings has been calculated according to ÖNORM.
- Based on this, elements of comfort for these buildings are deduced and evaluated.
- Individual system-components are described and their coaction within the complete system is reviewed.
- Special focus lies on the “panel heating”.
- For so far archaeological undetected components suggestions are made as to their possible appearance. Purpose is to give colleagues tools to look during analysis of past or future excavations upon leftovers of hypokaust heating systems from a new point of view: “you find what you know or what you are looking for”.
- Flow conditions in the hypokaust are presented. (Schematically and – for the first time – computer simulated)
- Heating process, combustion and aptitude of different fuel are examined, including evaluation-criteria.
- Problems with reconstructed equipment are addressed, probable causes presented, possible correctives shown.
- Suggestions for proper usage are given.
- Heretofore accepted facts are challenged, partly newly interpreted or differently solved.
Keywords: Roman Hypokaust Heating System