How Topture's Barrel, Cube, and Cabin Saunas Forced a Rethink of Outdoor Ventilation Details

https://www.bookmark-step.win/why-material-choice-often-outperforms-chasing-6-air-changes-the-case-for-1-5-to-2-inch-timber-thermal-mass

When product variety revealed an architectural blind spot Topture launched three distinct outdoor sauna families in a single season: the curved Barrel, the compact Cube, and the vertical Cabin