Why are areas of some buildings so hot in the winter?

There are a wide variety of heating systems and heating control systems in our buildings. Some of the types of heating control systems are:

  1. individual room control,
  2. zone control, and
  3. building control. 

Check out Heating and Cooling Tips for more information.

Individual room control provides the best comfort control. A wall mounted thermostat or temperature sensor, or an adjustable thermostatic valve mounted on the heater, controls the temperature in each room. Nesmith, Smith Hall, and McConnell are examples of buildings with individual room control. If you have individual room control, and your area is too hot during cold weather, there is probably an energy-wasting equipment failure that should be reported. Zone control is a less expensive method to install.

Zone control does not provide the degree of comfort afforded by individual room control. With zone control, one control device (thermostat, wall sensor, or heater-mounted control) determines the amount of heat provided to several rooms within a zone. Generally, the room with the control device is the most comfortable. Other rooms in the zone receive heat based on the needs of the room with the control.

One common problem with zone control (and individual room control) is the use of electric space heaters. If a space heater is used in the room where the control device is located, the space heater may warm that room to the point where no other rooms in the zone receive any heat. Another typical problem with zone control is differing sun exposures or heat loads in different rooms within the zone. For zone control to work properly, all rooms in the zone must have essentially the same need for heat at all times.

Hewitt Hall, Kendall Hall, and the Printing & Mail Services Building are examples of buildings with zone control. If your room is too hot during the winter in a building with zone control, the room with the control device may be calling for heat even though your room doesn't need any.

Building control is the least expensive method to install, with the least degree of comfort control. There are no individual control devices in rooms within the building. The entire building receives heat based on the outdoor air temperature. As it gets colder outdoors, the heating water circulating throughout the building automatically gets hotter. The device controlling the water temperature must be set to keep the coldest room, with the most windows, on the northwest corner of the building warm. That usually results in many other areas of the building overheating, especially those with an interior or southern exposure.

Pettee Hall, and many of the residence halls are examples of buildings with "building control." If an entire building with "building control" is too hot, there may be an equipment failure that should be reported. If only certain areas of the building are too hot, that is probably necessary in order to keep the colder rooms in the building warm.