WHERE & WHENc. 1ST–4TH C. CE
Roman Britain, England. This scene represents a generic bath-house heating bay rather than one surveyed site; examples survive in England at Bath, Ravenglass and Roman villa sites.
WHY IT MATTERED
Heat supplied from beneath floors shows how builders integrated masonry, air passages and skilled furnace tending into a thermal system long before modern building services.
Educational steady-state control-volume model. Air density ρ = 1.2 kg/m³, cₚ = 1.005 kJ/(kg·K), effective heat efficiency η = 0.56, reference room air 20°C and illustrative U = 3.2 W/(m²·K).
ṁ = ρ V̇
Q̇air = η P
Tin = 20 + Q̇air/(ṁ cₚ)
Q̇floor = min(0.92Q̇air, U A (Tin − 20)/1000)
Tout = Tin − Q̇floor/(ṁcₚ)
The model assumes constant density and heat capacity, ideal mixing, one effective conductive transfer coefficient and no detailed combustion or heat storage. Temperature outputs are scenarios, not archaeological measurements. The flow tracers, room shape and 1.75 m figure are illustrative. Dimensions are schematic.
Illustrative reconstruction, not an official model and not affiliated with any institution, company or manufacturer.