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Effective winter shelter required understanding heat movement—how it escaped buildings, how losses could be prevented, how minimal heat sources could maintain survivable interior temperatures.
Conduction removed heat through direct contact—the cold ground drew warmth from floor, the cold air outside pulled heat through walls, roof, any surface in contact with exterior. The counter was insulation—materials trapping air, creating barriers that slowed heat transfer, the more insulation providing better protection. The thick walls, the layered roof construction, the raised floors—all addressed conduction, creating thermal barriers between warm interior and cold exterior.
Convection carried heat away through air movement—the drafts that entered through gaps, the rising warm air that escaped through roof, the continuous exchange that exhausted heat sources. The solution was sealing—blocking air infiltration, preventing drafts, creating enclosed space where air movement was minimized. The Germanic builders understood this intuitively even without theoretical framework, they observed that buildings with fewer gaps stayed warmer, that sealing cracks improved comfort, that the tighter structure was the less fuel it consumed.
Radiation transferred heat directly to cold surfaces—the body radiating toward cold walls, the heat escaping through this mechanism even when conduction and convection were controlled. The partial solution was interior finish—covering walls with materials that warmed quickly, that themselves provided slight insulation, that created thermal mass reducing radiation losses. The complete solution required keeping walls above certain temperature, requiring either thicker insulation or accepting that some radiation loss was inevitable.
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