Despite name, an under counter microwave generally install to wall under Cabinet. If you have an under-cabinet microwave you want to install in a closet with no back wall to install it on, you have a few options for how to place unit.
If you do not have a back wall to install an under counter microwave, a wall mounting kit be of no use. But some manufacturers produce cabinet – mounting kit for this very reason. A sub – chassis mounting works same way a wall-mounted one, but components of kit to install bottom case, instead of to a wall. Before attempting to install an under-cabinet microwave, you must know weight restrictions in cabinet that can generally be found in original plans for kitchen.
Main problem with installing an under counter microwave without back wall is ventilation. A sub Chassis microwave generally vents from bottom, which means that microwave oven cannot sit directly on a table top. If you place microwave directly on a surface, device will not be able to vent and may overheat. One solution to this venting problem is to sit a microwave meant for under-cabinet use on a mask or wire frame with a slatted floor surface. In this way, microwave is still fanning.