Large air compressors need to be installed properly in order to maximize equipment live and safety, and minimize operating noise. First pick a suitable location. A compressor has to be installed on a sturdy floor such as concrete. The weight of the machine and vibrations during operation can damage other types of floor. Installation on a wood floor is particularly worrisome. The floor and walls will amplify the operating noise of the compressor.
Besides the flooring also consider machine clearances and the source of air. Compressors can overheat when they are placed too close to a wall. On some reciprocating models the fly wheel acts as a fan. If the compressor is placed too close to a wall, the fan-action of the flywheel is limited. The compressor overheats. Placing a compressor in a closet is particularly worrisome. The compressor will create negative pressure in the closet as it sucks up all available air. The motor will work harder; the compressor gets hotter. Make sure the closet has enough vents to allow for an adequate air circulation.
The air supplied to the compressor must be reasonably clean. The air filters on most compressors are designed to filter only small amounts of particulates from the air. In some environments they clog easily. In a woodshop this means the compressor cannot draw air from a space filled with wood dust. If you own an air cleaner you know what I mean. If your shop does not have adequate dust collection, there is a danger that the compressor will pull wood dust into its filter. If that happens the filter can clog in minutes. Either have the compressor draw air from a clean source, or do not operate it until the dust has settled in your wood shop. Enclosing the compressor in a closet helps, but does not solve the problem completely. The compressor will pull air and dust into the closet as it operates. Less dust will reach the compressor, but the usable life of the filter will be shortened.
The compressor should be mounted on vibration pads. This limits the transmission of vibration to the floor, which subsequently results in quieter operation. Vibration pads are typically made from plastic or rubber. Match the type of pad to the weight of your compressor. Do not use hockey pucks. They are far too stiff and do not dampen vibrations. Vibration pads are only marginally more expensive. Vibration isolation mounts are the most more expensive option. Unless the compressor's manual requires their use I would not consider them due to price.
For safety reasons the compressor should be bolted to the floor. Drill holes for expansion bolts through the feet and pads into the floor. The bolts keep the compressor in place on the vibration pads and make it impossible for the compressor to tip over. Some sources claim that the bolts keep the tank in place in the unlikely event of explosive decompression. While this extremely unlikely event can happen, keeping the compressor firmly situated on top of the vibration pads is the main reason for bolting the compressor to the floor.
In summary, the location of your compressor matters. The floor must be sturdy and the compressor must draw from a quality air source. Mount the compressor on vibration pads. Secure it to the floor with bolts.