The important thing to remember about "VOCs" is that this term refers to 1000s of potential airborne chemicals that belong to the grouping "Volatile Organic Compounds". The VOC sensor reports a value for the estimated presence of any VOCs present. Sounds scary or complicated? Don't worry! Not all airborne chemicals are harmful in the way we might think. Healthy humans alone are known to produce 100s of VOCs themselves through breathing and dermal excretions.
VOC spikes indicate an "event" has occurred
If you see a spike in your VOC readings, it is normally the result of a particular event occurring in the area where the sensor is located. By "event" we mean something has happened in the area that triggered the VOC spike or gradual increase in levels.
In order to find out what caused the spike or increase in levels, the best question you can ask yourself is "What changed in the room at that time?"
Here are some typical questions you can ask yourself to find out what may have caused the "VOC event" in a room:
Did anyone start cooking in the area?
Did anyone take a shower?
Were freshly washed clothes hung out to dry?
Did anyone clean the area using cleaning products?
Did a fan or ventilation system start running at that time?
Were any candles burned, or fragrances used in the area?
Did ventilation decrease in an area that is normally well-ventilated?
Human presence causes VOC levels to rise
As mentioned earlier, humans (and animals!) are also sources of VOCs. If a room was occupied at the time VOC levels started to rise, this is very normal and expected. The VOC sensor is either reacting to something a person was doing in a room, or to the human presence itself (breath, sweat, or other bodily gases).
We often receive the question from users "Why do VOC levels increase in my bedroom at night?" and the answer is likely that the VOC sensor is naturally reacting to the build-up of breath and results of other bodily functions in the room during the night.
So what should you do if you notice a spike or increase in VOC levels?
When VOC levels increase to actionable levels, it means the air in the environment probably isn't the freshest and could benefit from some ventilation. Opening a window or door is a great way to introduce more airflow and fresh air into the area.
If VOC levels rise in a room that wasn't occupied and where no known event occurred
It's time to do some investigating 🔍! A great way to find out what might be causing a rise in VOCs is to look at the behavior of your other sensors. For example, does humidity or temperature noticeably increase around the time of the VOC increase? When temperature increases, it can cause some VOCs to off-gas at a higher rate. For example, if VOC increases when the temperature rises in a room, it might be that VOCs from the furniture are off-gassing more - this would especially be true for new pieces of furniture.