How a 1973 Water Roof Kept a House at 70°F With No AC and No Furnace

In 1973, a revolutionary house was built in Atascadero, California, that required no furnace and no air conditioner. Designed by chemist Harold Hay, this home utilized a brilliant "water roof" system consisting of water sealed in giant bags beneath sliding insulation panels. This passive heating and cooling system kept the indoor temperature between 68°F and 72°F all year round without electricity, pumps, or any backup systems. Discover how this forgotten Skytherm house used thermal mass and night sky radiation to replace conventional HVAC systems, and learn why this genius off-grid cooling method was ultimately abandoned by the industry. Table of Contents: 00:00 The 1973 House With No AC and No Furnace 01:35 Harold Hay and the Water Roof Invention 03:10 How the Passive Heating and Cooling System Works 04:45 Summer Cooling via Night Sky Radiation 06:15 Winter Heating with Solar Thermal Mass 07:50 Why the Skytherm House Was Abandoned 09:20 DIY Passive Cooling and Free Cooling Methods Hashtags: #NoAC #PassiveCooling #OffGridLiving #Skytherm #SustainableArchitecture