joules word of the month

A setpoint is "the [temperature] point at which a thermostat has been set". Straightforward, right? 

set points

Many thermostats have 2 setpoints, a heating setpoint a and cooling setpoint. 

 

Going over temperature setpoints may seem elementary, but Joules chose this Word of the Month for a reason. Adjusting these points, even by a few degrees, can cause major energy-saving differences in a building. 

 

How do setpoints work?

Setpoints work relative to the room temperature. The Heating, Ventilation, and Air Conditioning (HVAC) system works to bring the room temperature to the set point temperature. 

 

For example, if your room temperature is 78°F, and the setpoint is 76°F, then the heating and cooling equipment will work to cool the building to that setpoint. Some thermostats have one setpoint, and others have two: a heating set point, and a cooling set point. 

  • For a heating set point, the HVAC system will heat the room to the setpoint temperature and try to maintain that temperature.
  • For a cooling set point, the HVAC system will cool the room to the setpoint temperature and try to maintain that temperature.  
  • If the room temperature is within the two set points, or within the comfort band, the HVAC system will not heat or cool the space (although it may continue to provide ventilation to your room.)

Air Conditioning usually accounts for at least half of a building's energy use, so adjusting setpoints in a building can make a huge difference when it comes to energy savings!

 

How can we use setpoints to save energy?

 Typical office buildings consume large amounts of energy maintaining their occupied spaces within temperature ranges that are often very narrow. This energy usage can be reduced significantly by widening the setpoint range to include a larger range of temperatures (a range that we call our Comfort Band). 

 

calculator
In this online tool developed by UC Berkeley, you can see the impact for yourself!  http://comfort.cbe.berkeley.edu/energycalc/

 

It's important to remember that a room meeting its set point temperature does not always equate with comfort. Your comfort in a building depends on several factors, including how you think the room feels! That's why we need occupants like you on campus to use TherMOOstat to submit their comfort feedback. With TherMOOstat, you can tell us if you're too hot, chilly, or perfect. Even "perfect" feedback is useful because it lets us know that the setpoint for your room is optimal! 

 

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