Summer Temperatures Surface Unknown Relationship

With rising Spring-Summer temperatures we see a strong correlation between indoor temperature and TVOC levels in this chart.

The Total Volatile Organic Compound (TVOC) level is a measurement of the sum of all of the volatile organic compounds (VOCs) found in a room. VOCs comprise a broad range of chemicals that easily evaporate into the air at room temperature (have a high vapor pressure at ordinary room temperatures). Many consumer products release VOCs including solvents, paints, adhesives, building materials, and furnishings.

These TVOC levels are not high but suggest a moderate likelihood that specific VOC sources may be present. Further investigation is recommended if complaints of irritation and discomfort are received.

What may be causing the rise in TVOC levels in this space? One possibility is a very large rug located in the 3rd floor ballroom. The room is approximately 20ft x 40ft, and receives afternoon sunlight through windows on the front of the building.

The sensors are located on the third floor of a historic building that is closed due to the pandemic. The building AC is on and set to run for normal operations.

This temperature-TVOC relationship may need to be considered and accounted for when utilizing TVOC levels to characterize other parameters including occupancy density; a baseline is essential. Interestingly, the relationship is equally sensitive as temperature rises and falls rapidly dissipating, no lingering decay.

Temperature in orange, left scale. TVOC in green, right scale.

Please see August 15th post for further analysis.