Air cleaner

It is a powerful air purifier that uses G4 and H7 filters. The HEPA H7 filter can effectively collect plant pollen. This air purifier is designed to clean indoor air during allergy seasons.

What is needed 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 contaminated, resistance increases. The centrifugal fan is powerful enough to create the necessary air flow, even when using a filter with maximum performance.

When choosing a fan, I made a mistake. Its power is not regulated. It either works (very noisy) or does not work.

The fan is located in the housing and creates a draft that causes air to flow through the filter.


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


Since I used foam material to damp the vibrations of the fan, it was difficult to immediately determine the place of the outlet. I cut it myself with a drill. Not very neat, but it will not be visible.

Fan mount

In any places where the fan touches anything, foam material was used to isolate the noise. Given the severity of the fan, it was necessary to mount it on two surfaces. A laser-cut frame will be used for the outlet. Bolts go out. I did it this way because I made a noise isolator for the outlet, and the protruding bolts will help in fixing it.

Case Sealing

In order for the low-pressure chamber to be filled with air only through the filter, I used wood putty to seal it. The output of the electric wire is another weak point. I drilled a hole smaller than necessary for the wire diameter, and slightly enlarged it with a file. So everything more accurately came up.

Electrical box

I glued the electrical box on the back of the case. Since the fan is not adjustable, I put a simple switch in two positions. So that in case of overheating, air circulation occurs, I drilled several holes in the box on the sides, which is not the best option.

Installing an air 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. For better sealing of the filter, a sealing elastic band, which is usually used in windows and doorways, was placed between it and the frame.

The last filter element is simply inserted inside. Due to its exact dimensions, it is motionless inside.

To close the case with a laser, a more or less elegant lattice was cut. It creates a fairly strong resistance to air, so the design must be securely fixed.

Original article in English