Office Mechanical Systems

Looking at the mechanical system, let’s focus on the mechanical room first. The mechanical room should be located nearest the equipment it will serve, if possible. The first consideration is the location of the building’s waste and water stack. If you are located in an office building, for example, the current building codes with regard to waste (open site drain, slope on piping emanating from the operatories to the mechanical room, space below your slab to run said piping) are important considerations. Secondly, since the dental equipment will require compressed air, water, vacuum and electrical services, locate this facility nearest the equipment it will serve. For example, it is essential that adequate slope be provided to reduce the potential of NaOCl accumulation and subsequent corrosion of the copper vacuum piping (most fire codes don’t permit inexpensive PVC). To eliminate the corrosion problem with copper pipe, I recommend that the vacuum line from the operatory to the vacuum device be made of PVDF type plastic pipe, since it does not corrode, is non-PVC and is approved for plenum ceilings (fireproof). See specifications below. It is available from Orion Fittings, Inc (

Co-locating the vacuum pump and air compressor with the electrical circuit boxes in a single room is desirable. Also providing sound insulation such as a solid core door with weather-strip, batt insulation in wall cavity and extending the perimeter walls around this mechanical room from floor slab to ceiling slab are essential. Provide backing plates such as 5/8 inch plywood screwed between studs, before wall closure, in key areas for attachment of equipment to the walls. Also, application of plywood, before painting, to portions of the wall interior can be helpful to attach junction boxes, etc. and should be planned in advance. I do not recommend locating any telephone or computer equipment in this room unless the compressor is oil-less.

Stacking the compressor and vacuum systems save space while allowing easy access to each piece of equipment (See illustration). A porcelain or ceramic tile floor with 4-6″ cove tiles will allow easy cleaning. Carpet in this area is not a good idea.

The recommended specifications for Orion PVDF socket fusion corrosive waste drainage system is as follows: “The corrosive waste drainage system, conforming to ASTM F1673, shall be Orion’s Super Blue PVDF (Polyvinylidene Fluoride) pipe and fittings. The pipe and fittings shall be joined using the Orion socket fusion system conforming to ASTM 2657. The pipe shall be supplied in 10 ft lengths. The fittings shall meet or exceed Schedule 40 dimensions. The PVDF material shall conform to ASTM D3222. Pipe shall be marked with UL Classified to indicate compliance with UL 723 (ASTM E84).”