What is the minimum indoor temperature required for spaces intended for human occupancy on the design heating day?

What is the minimum indoor temperature required for spaces intended for human occupancy on the design heating day?

• A. 65 degrees F
• B. 68 degrees F
• C. 70 degrees F
• D. 72 degrees F

Answer: (B)

On the design heating day, the minimum indoor temperature for spaces intended for human occupancy is 68°F. This value serves as the comfort baseline used when sizing heating systems to ensure occupants stay comfortable even under the coldest expected outdoor conditions. It provides a practical balance between delivering enough warmth and avoiding unnecessary energy use, given typical building envelopes and heat gains. Some spaces may be allowed to be cooler if they’re not regularly occupied, but for spaces where people live or work, 68°F is the standard target. A lower number, like 65°F, might be acceptable in certain codes or situations, but it doesn’t represent the common minimum for occupied spaces during design conditions. Higher targets, such as 70°F or 72°F, exceed the minimum and imply more heating capacity than strictly needed for design conditions.

On the design heating day, the minimum indoor temperature for spaces intended for human occupancy is 68°F. This value serves as the comfort baseline used when sizing heating systems to ensure occupants stay comfortable even under the coldest expected outdoor conditions. It provides a practical balance between delivering enough warmth and avoiding unnecessary energy use, given typical building envelopes and heat gains.

Some spaces may be allowed to be cooler if they’re not regularly occupied, but for spaces where people live or work, 68°F is the standard target. A lower number, like 65°F, might be acceptable in certain codes or situations, but it doesn’t represent the common minimum for occupied spaces during design conditions. Higher targets, such as 70°F or 72°F, exceed the minimum and imply more heating capacity than strictly needed for design conditions.