The groundwater system can heat the air in the school because the groundwater is warmer
than the air in the school. This means that the molecules in the water have a higher average
kinetic energy than the molecules in the air. When the molecules collide, energy will transfer
from the water to the air, warming the air. This will happen even though the groundwater isn't
all that hot. As long as it is warmer than the air, it will heat the air