Air purifier

This is a powerful air purifier that uses G4 and H7 filters. HEPA H7 filter can effectively collect plant pollen. This air purifier is designed to purify the air in a large room during allergy seasons.

What do you need for an air purifier?

The fan must be selected depending on the characteristics of the filter. Filters differ in air permeability, as well as in creating a certain resistance to flow. When they become dirty, resistance increases. The centrifugal fan is powerful enough to create the required air flow, even when using a filter with maximum performance.

I made a mistake when choosing a fan. Its power is not adjustable. It either works (very noisy) or doesn't work.

The fan is located in the housing and creates draft, which forces air flow through the filter.

Frame

The fan is mounted inside the housing, which is made of laser-cut 5 mm plywood. Since the fan itself is heavy, and a strong base is needed to attach the filter, the lower part of the housing is reinforced with wooden elements. They were cut the same length, but did not fit perfectly tightly.I used wood putty to fill the voids and seal the system.

Outlet

Since I used foam material to dampen fan vibrations, it was difficult to immediately determine the location of the outlet. I cut it myself using a drill. Not very carefully, but it won't be visible.

Fan mount

Foam material was used wherever the fan came into contact with anything to insulate the noise. Given the heaviness of the fan, it had to be mounted on two surfaces. A laser cut frame will be used for the exit hole. The bolts come out. I did it this way because I made a noise isolator for the outlet and the bolts sticking out will help in securing it.

Housing sealing

To ensure that the low pressure chamber was filled with air only through the filter, I used wood putty to seal it. The electrical outlet is another weak point. I drilled a hole smaller than the diameter needed for the wire, and enlarged it a little with a needle file. This made everything more accurate.

Electrical box

I glued the electrical box to the back of the case. Since the fan is not adjustable, I installed a simple two-position switch. To allow air circulation in case of overheating, I drilled several holes in the sides of the box, which is not the best option.

Installing an air cleaner filter

The H7 filter is mounted in a wooden frame, which is attached to the reinforcing elements of the housing, which gives additional strength to the entire structure. To better seal the filter, a sealing rubber band, which is usually used in windows and doorways, was placed between it and the frame.

The last filter element is simply inserted inside. Thanks to its precise dimensions, it remains motionless inside.

To cover the case, a more or less elegant grille was laser cut. It creates quite strong air resistance, so the structure must be securely fastened.
Original article in English