In what time period did residential central heating and cooling systems become popular?

Residential central heating and cooling systems gained widespread popularity in the late 1960s. This period marked a significant shift in home design and construction as advancements in technology and manufacturing made these systems more accessible and affordable for the average homeowner. Air conditioning units could now be installed in homes without extensive modifications, leading to increased comfort during warm months. Additionally, the growing awareness of indoor air quality and the need for heating solutions during colder months contributed to the adoption of these systems in residential settings. The late 1960s also coincided with changes in building codes and the development of better insulation materials, which enhanced energy efficiency and made central systems a more viable option for homeowners.