I recently bought the wifi enabled purifier and after downloading the app , i realised how useful the  the built in sensors on the unit are for monitoring the temperature and humidity in a bedroom which regularly experiences condensation  and high humidity.

The bedroom itself is north facing 9.5 square metres and my 2 teenage daughters sleep and virtually live in the room. ( high occupancy)The typical hole in the wall natural ventilation is not providing sufficient air changes per hour to cope with the amount of moisture they expelling into the air in the room every particularly at night time when they are asleep so each morning we are greeted to a film of moisture on their double glazed metal windows.

I have studied condensation risk in buildings and learned how to use the WUFI software which allows you to analyse the risk of condensation and as a byproduct mould in your building. To simplify it the critical thresholds are if the temperature in a room drops below 15 degrees and the relative humidity in the room rises above 80% you now have the ideal environment for mould to grow plus if you add in something for mould to feed on ( the paper on the back of your plasterboard) you may be in trouble . Especially if these  thresholds are regularly breached you will more than likely have mould in that room. The problem will be compounded if you have poor insulation ,if your insulation is not continuous ( in coverage and depth) and if your building is not airtight. This is why the mould will invariably present itself around the perimeter of your room, in the corners and at your window reveals.

This is why the app and the data it produces is helpful, the app monitors the internal room temperature and the room humidity and it also provides the external air temperature and relative humidity. In my own studies i have analysed and graphed the external climate data files for my area and graphed them to show the effect of increasing insulation on the wall, the effect of wind driven rain on a north facing wall, the lack of solar radiation on a north facing wall ( wall can’t dry in december, january or February eventually drys out by summer only for the cycle to start again in winter ) , the effect of using drylining versus external insulation etc ( don’t use drylining) . 

But anyways to Dyson your product is screaming out for the end user option to automatically switch on when the temperature drops below 15 degrees. Can the firmware be updated to include this option. Also is it possible for the end user to be able to access the data for each month in a csv file to facilitate further analysis?