noun
thermal insulation properties; heat-insulating quality
Technical term used in engineering, architecture, and product specifications to describe how well a material or structure resists heat transfer.
この窓ガラスは断熱性が高いので、冬でも部屋が暖かい。
This window glass has high thermal insulation properties, so the room stays warm even in winter.
断熱性を向
To improve the thermal insulation, we added insulation material to the walls.
保温性 emphasizes heat retention (keeping warmth in), whereas 断熱性 is about blocking heat transfer in either direction.
Compound of 断熱 (thermal insulation) + 性 (property, quality). 断熱 is itself a compound of 断 (cut off) and 熱 (heat).