An image of Wellman Hall

What's Really Going on in Your Classroom

An Inside Look at Wellman's HVAC

Have you ever raced to class, shuffled into a classroom with 100 other students and spent the next 15 minutes sweating in your seat wondering if you smell bad? Or have your beads of sweat turned to ice when the AC blows directly on you?

In this post, you’ll find out what goes on behind the scenes before you sit down and long after you’ve left. Let’s take a look into Wellman Hall. Whether you’ve had classes in Wellman, or taken a quick nap inside, the same type of processes occur in other buildings around campus.

 

6am

Our story begins in the wee hours of the morning, when the classrooms are dark and quiet. Around 6am, the building comes to life. The fans turn on and the building uses 62° F outside air to cool the rooms. Air temperatures mix to create 70° F air in the rooms. This may seem chilly, but this temperature helps keep the rooms cool with the upcoming onslaught of students. Let’s explore in a little more detail and see what’s going on in classroom number 26.

 

9am

Just after 9am the temperature is still about 70° F, but the room will quickly warm up as students trickle in for class. When class starts at 10am, the room is roughly 74° F. Since morning classes are a little smaller and the outside temperature is relatively low (in the 70s, °F), the room’s air conditioning units can maintain this temperature by simply increasing air flow.

 

1230

It isn’t until people start packing the room for their 12:10pm class that things get heated. At 12:10pm, it’s about 74° F inside the classroom, and about 81° F outside. The room soon reaches its maximum occupancy, 120 people. The temperature in the room rises to 76° F in 15 minutes. The air conditioner responds by increasing air flow and brings the room temperature back down to 75° F. It’s an uphill battle though with all those warm bodies and flowing brain juices, so the temperature starts to creep back up.

 

345

At 3:45 p.m., classes have been underway for several hours and the room has consistently had about 120 people in it. The room reaches a temperature of 77° F between 3:45pm and 4:30pm. The air conditioner has been steadily supplying 62° F air, at the room’s maximum rate of about 1400 cubic feet per minute, but with outside temperatures hovering around 92° F, it’s doing everything in its power to keep the room comfortable.

 

7pm

By 7:30 the day’s classes are over and the room temperature drops back to 71° F. The building gets a reprieve, until tomorrow…

Let’s take a quick look back to see how the room temperature fluctuated throughout the day. As you can see, the number of people in the room, air flow, and outside temperatures all affect the temperature in the classroom.

graph

 Related Articles