Is your building playing tricks on you?

Have you ever felt like your building has a mind of its own or isn't performing like you think it should? Sometimes the root of your HVAC issues aren't obvious and a little trickier to solve. We ran into two such situations on a recent jobsite!

The first problem was that some spaces felt cool to the occupants and when reviewing the BAS (building automation system) in action and through reviewing trend logs we could see that perimeter rooms struggled to maintain space temperature setpoint even though the HVAC system was delivering plenty of heat into the spaces. What we were able to capture was stratification of the hot air in the space was not properly mixing and reaching the thermostat level. The BAS kept the heat on high and the VAV box serving these spaces were putting out air that exceeded 120 degrees F in an attempt to heat the spaces up. The problem was that this air was too warm and caused it to stay in the upper portion of the rooms rather than mix with the cooler air closer to the floor.

This restroom was cold to the occupants.

While it is counter intuitive. Sometimes you can put too much heat into a space! ASHRAE recommends limiting the discharge air temperatures to 95 degrees. We find this is a good starting point, but there can be a little wiggle-room to this limit if need be.

This is a great example of stratification of the warm air near the ceiling vs. cooler air at the floor.

In another area of the building, the space seemed to have a mind of its own and would randomly cool down at different times of the day. This hallway had a row of south-facing windows and as the sun progressed from east to west, the sun shines onto the space temperature sensor on/off throughout the day. When the sun shines on the sensor, the solar loading effect happens and the BAS thinks the space is too warm and shuts the heat off (in the winter). The problem is that the actual temperature of the space wasn't as warm as the BAS thought it was and resulted in occupants feeling cool on and off throughout the day!

Poor placement of a space sensor was causing headaches for the Owner and occupants!

If you are having problems in your building that you just can't figure out, give us a call and we'll help to shed light on the root cause! See what we did there?...