In a heating-only climate, an uninsulated heating duct running through a garage will deliver ______ air to the room at the other end of the duct.

In a heating-only climate, an uninsulated heating duct running through a garage will deliver cool air to the room at the other end of the duct. This occurs because the duct, being uninsulated, will lose heat to the cooler environment of the garage. As the heated air moves through the duct, it encounters the cold surfaces, causing the air to cool down before it reaches its destination.

In contexts where external environments are cooler than the heated air being delivered, uninsulated ducts can significantly reduce the effectiveness of heating systems, as the air temperature can drop substantially, leading to a less comfortable indoor environment.

Heated air should ideally remain warm on its path to the intended heated space, but without insulation to retain that heat, the duct simply cannot maintain the desired temperature. Therefore, the air reaching the room is likely cooler than anticipated.