Lots of residents have questions about air conditioning at this time of year. Unlike a residential heating, ventilation and air conditioning (HVAC) system that just involves flipping a switch to turn on the AC, our large buildings work with a different type of system that pumps heated or cooled water through pipes that run throughout the building, and then in each student room there is a blower unit which blows air across coils that are being heated or cooled by this water. In the winter, hot water is pumped through the system, which provides the ability to turn on the blower in your room and receive heat. In the summer, we pump chilled water through the same pipes and that produces air conditioning in each room.
The problem is that we can only supply one or the other at a time-–hot or chilled water-–and the process of switching over from one mode (heat) to the other mode (cooling) takes several days. Housing has to be able to supply heat until June 1, according to Chicago ordinances, so can’t switch building systems until the weather is consistently warm enough. Since heat is considered a basic life necessity (while air conditioning is not a basic life necessity), the City of Chicago has a heat ordinance which states that we are required to provide a minimum indoor temperature of 68 degrees during the daytime hours and 66 degrees during the overnight hours from September 15 through June 1 each year. The other issue is that our AC systems will not operate when the outside temperature is below a certain point in the 60s. When that occurs, the large chiller unit on the roof that provides the chilled water for the AC shuts down to prevent it from being damaged by running when the outside temperature is too low.
Because air conditioning in residence halls is much more complex than just flipping a switch and turning it on, our Facility Operations is continuously monitoring the forecast and will make the switch from heat to AC as soon as they are confident that the nighttime lows will not be too low where heat would be required. Historically, this switchover usually occurs sometime in mid to late May, but is entirely dependent on the forecasts. Our weather can vary widely in Chicago as seen with snow as recently as April 27, then warm weather predicted for April 30. When the time is appropriate, Facility Operations will make the switchover. If your room is feeling warm on a day with higher-than-usual temperatures in the interim, we recommend turning off the blower unit in your room or running a separate small fan near the window to pull cooler air inside.