What is required if a furnace is used for temporary heat in a residence under construction?

When a furnace is utilized for temporary heat in a residence under construction, it is essential for the furnace to be installed on a finished concrete floor that is at least 4 inches thick. This requirement ensures stability and safety during the construction process. A proper foundation helps to prevent any potential issues with movement or imbalance of the furnace, which could lead to operational hazards or even damage to the unit.

Additionally, placing the furnace on a concrete pad ensures that it is protected from moisture, which can be a concern on construction sites where water may accumulate. The thickness of the concrete floor is specified to ensure it can adequately support the weight of the furnace while maintaining a level surface.

To fully understand this requirement, it's important to consider the function of the furnace and the environment in which it is being used. Temporary heating systems are often in constant use during construction, and a solid base is critical for the safe operation of any heating equipment.

The other options do not align with the necessary protocols for ensuring the safety and efficacy of the furnace during temporary heating applications in an unfinished home.