Hi, 

This isn’t something that I've experienced, but I do remember someone posting a similar question a while back. The “Best answer” on it looks like it answers your question as well..

Whilst VOC is produced from the likes of cooking, burning fuels, perfumes and cleaning products. The sources that product VOC omit a gas, which is detected by our Purifiers and are drawn into the machine passing through the filtration system to remove it from the environment. This gas decays at a steady rate as the air in the room is passed through the machine and clean air is expelled.

This process can be affected by what is called ‘Off gassing’. This is where a source is producing the gas at a rate higher or the same that equals the machines purification. I must stress that this is extremely rare and if the former were the case, the machine would read this as Severe/Purple. However, as it has taken a couple of days to clean, I suspect what has occurred is that a source introduced into the space is/has omitting the VOC gas at a continuous rate that the machine has detected under it under the Fair/Yellow reading on your graph. This reading indicated that the machine has detecting a moderate level of the type of pollutant. As the machine has been successful in reducing this VOC reading and bring it down to the Good/Green. Detecting a very low level of the type of pollutant, I would suggest that something within the space has now stopped producing the gas.

The ’Explanation of the pollutant levels and colours on the graph’ should help understand what the readings on your graph indicate. 

The importantly thing now is to locate what in the home is producing the gas. This can be done through trial and error. Changing cleaning material, moving the purifier to a different location in the room and/or checking for points when outside air can enter the room are only a few suggestions.

In terms of the machine, as Dyson Purifiers are designed to ‘In maximum setting. Tested for air projection, purification coverage in an 81m³ room', I would suggest running your machine in AUTO mode. Using AUTO mode means the on-board sensors will intelligently adjust the settings of the machine according to the air quality. The airflow speed will increase until the target air quality. This is a pre-set reading within the Good/Green.

Best of luck.

Charlie

Hi @Peggy Be 

Expectant mother here and probable someone that is a little over cautious. 

I notice a jump in the VOC reading of ours every time I clean or sanitise the nursery (I am a clean-a-holic). 

It also jumps up when I blow out the candles at the bottom of the stairs. My assumption here is that the fumes rise and are being blown by a draft and drift into the room. 

I’m looking at using less harsh cleaning products (the high reading lasted for some time) and have already moved the candles. 

Maybe this is similar to what your seeing? Is it only there when you clean or are fumes drifting into the room?

Emma :)