COVID respirator : electric fan ventilated mask

Here is an adaptation of an inhalation steam mask. It is now a COVID19 respirator with fan assistance.
The fan is a standard 30x30 mm 5V one used to cool raspberryPI

I have added exhaust valves. They work really well, the mask is totally sealed without leaks when you breathe and close the fan inlet.

As a filter you can use cotton pads or cut it from a chirurgical mask (5 from one single mask !)

I have tried to breathe with it. The fan helps a lot altough more air would be better...
May be a 40x40 mm would push a little more air...

Power is delivered by a simple phone battery pack that you can hid into your pocket. SO that the weight is into your pocket and not on your face !