What is the minimum indoor temperature that heating systems must maintain in occupied spaces?

The minimum indoor temperature that heating systems must maintain in occupied spaces is set at 68°F. This standard is established to ensure that indoor environments provide adequate comfort and safety for occupants, especially during colder weather conditions. Maintaining this temperature helps to prevent health issues associated with excessive cold, such as hypothermia and discomfort, particularly for vulnerable populations, including the elderly and young children.

It is a common building code requirement that reflects a balance between energy efficiency and occupant comfort, ensuring that homes and buildings remain livable during winter months. By setting the minimum at 68°F, it allows for a reasonable level of warmth without placing undue stress on heating systems or contributing to excessive energy consumption.