Is Your Thermostat Being Tricked?

False loading can trick your buildng automation system resulting in increased energy use and cost, decreased equipment life-span, not to mention unhappy occupants.

We found an example of this false loading (see IR photo below) on a thermostat located on an exterior wall. The location on the wall just so happens to be a spot with insufficent insulation. This small under-insulated area usually wouldn't be a huge deal - but it is the exact location that the thermostat was mounted for this space!

During the winter the thermostat can read as much as 10 degrees colder than the actual space temperature due to thermal bridging in the under-insulated portion of the exterior wall. The building automation system (BAS) keeps pumping warm air into the space resulting in wasted energy and occupants that are too hot! In the summer a similar problem occurs: the thermostat reads hotter than the space actually is due to thermal bridging from the exterior; the BAS overcools the space, wasting energy.

Durring the hottest and coldest parts of the year then, the air handling units are running 24/7 instead of following their occupancy schedules because the thermostat is feeding data to the building automation system that doesn't accurately reflect the space temperature.

What can building Owners do?

1. In existing buildings: if you have thermostats located on exterior walls, use an infrared camera to check for thermal bridges. If you find this issue, insulation can be added, or the thermostat may need to be moved.

2. During the design of new buildings or remodels: it is best practice to NOT locate thermostats on exterior walls - does the design show this? Do your installing contractors know this? If you want to be sure this, and thousands of other best practices are followed during the construction of your building, bring Cooper Commissioning on board!

This thermostat will read significantly cooler than what the room temperature actually is because it just happens to be mounted in a location that there is a thermal bridge due insulation not being installed correctly.