Recently, people have been complaining about the school being cold. This is how our middle school HVAC System works. Our middle school has a commercial HVAC system, unlike your typical residential systems. When our system operates, outside air enters our building per code. Depending upon the room sensor, either a hot or chilled water valve will open to achieve a designed output temperature. The downfall of our type of uni-vent system is the draft from the fan.
Once the zone sensor comes within two degrees of the set point, the hot or chilled water valves modulate not to surpass the set point. This leads to output temperatures dropping from the fan of the unit. 70-degree air blowing into a room creates a cold draft, like sitting in front of a fan.
The elementary classrooms’ uni-vents are ducted above the ceiling. This disperses the air from above providing a better comfort level in the classrooms.
Mr. Mortimer, Director of Buildings and Ground, stated, “Is 70 degrees cold? Are you going to freeze in 70 degrees? No, but it feels cold.” He also stated, “It’s the air blown across the room creating a draft.”
The classrooms are set around 70 degrees. The vents are like standing in front of a fan because of the constant draft. So if you’re feeling cold, just know the vents are blowing up to 70-degree air, but the draft is what makes the classrooms chilly and the outside air coming in from outside.
