The Knoll Life chair uses a Herman Miller Aeron-style design.
The seat has thin padding and a cloth cover similar to the SteelCase Leap chair. The end result is a firmer rather than more cushiony feel. The seat pan flexes towards the front edge, reducing the sharp pressure point at the front edge found in most chairs. In addition, the seat pan can be slid back/forward to create a longer/shorter seat to accomodate different users. However, the same lever that controls chair height also controls the sliding seat pan. The design is easy to use but placing the lettering on the inside of the lever hides it from the sitter’s view, so they may not notice the lever can do more than just adjust the seat height. The lettering for the seat pan slider is also quite small for some reason.
The backrest is made of mesh, like the Herman Miller Aeron chair. Herman Miller claims this design is to provide better ventilation for the body, though the Knoll literature makes no such claims. The back can be outfitted with an optional slip cover (defeating the ventilation theory). The backrest cannot be locked in a reclined position despite the armrests being well suited to use in while slightly reclined. The backrest reclining force is controlled by a difficult to find lever under the chair. Fortunately, adjusting this lever from minimum to maximum force results in a barely noticable difference in dackrest tension, making it difficult to tell what you’ve adjusted. This option will be nearly useless for heavier users whose torso mass will overpower the maximum backrest tension and force them to either be contantly fully reclined or sit with the backrest locked upright. The lumbar support is defined only by the contour/mesh of the chair. It adjusts somewhat to fit you automatically but doesn’t allow for selective adjustment for users who need specific support. Using the slipcover on the backrest creates more of a fixed location support that does not even auto adjust like the mesh alone.
The armrests slide up/down, forward/backward, side/side but do not pivot. They lower to within 5″ of the seat and will go extremely high above the seat (9″). This may be useful for people who type with the mouse/keyboard on the desk. The padding for the armrest is a plastic that does not feel durable.
The mesh back is purported to dissapate heat better than traditional backs. Many users comment that the mesh conforms comfortably to support their back.
This is a respectable application of the mesh-style chair. The nonadjustable lumbar support is a drawback. The mesh back provides some flexible support that is tailored to the user. This may be insufficient, especially for havier users. The synchronized seat pan/backrest is a nice idea but the tension on the backrest (force it takes to rock back) is not sufficiently adjustable or easy to figure out how to adjust. There is also no option to lock the seat reclined or adjust the back independently of the seat.