Design of an air purifier

We propose air purifiers. We need a new "industrial" product. These products contain a filtration cartridge, a fan and some electronics. Our main product for mass-market is ok, but we want an "industrial" product, not very esthetic, but practical. I attach a picture with the prototype of the product we want. Dimensions (approx): 300 mm length, 180 mm x 180 mm width and height (or diameter) Weight: inside will weight 1500 g The unit will work at usual temperatures. Device is plugged (220 V / 110 V), has a unique push-button, and has no screen. The air flows through a potential "protection grid", then the cartridge (25 cm length approx.), then the fan (5 cm), and then another protection grid. The product does not need to be hermetic in itself. Only the junction between cartridge and fan must be hermetic. Usage: - takes air on one side, pushes it on the opposite side (300 mm between these sides) - the cartridge can be removed and replaced, by opening a door on the "intake" side of the box - the "intake side" must slightly push the cartridge to maintain it on the fan and ensure it's hermetic. - the device can be fixed on a wall, or put on a table. If the intake side is square, the air flow will be horizontal. We may consider an option with a vertical air flow and a circular section of the intake-side Goal: - limited investment, limited target price. The unit must be designed with the goal to reduce price. - a nice product, but no "whaoo" effect. It's for industries, not mass market - probably in plastic (it's connected so the waves must go through it) I attach pictures of the current prototype (in metal) and the cartridge