Plan the Central Vacuum Tubing System
The amount of airflow that reaches the hose is dependent on the efficiency of the layout of the tubing system.
The Trunk Line
The trunk line connects the further inlet valve to the power unit. Branch lines flowing in to the trunk line will connect all other inlet valves. If the basement is unfinished, the trunk line is best run beneath the joists in the basement ceiling. The upper floors can be accessed through closets, cold air return ducts, or in partition walls. Alternatively, the trunk line could run straight up the attic and service the floors beneath by branch lines dropping through closet ceilings or partition walls. The location of the trunk line will greatly depend on the construction of the house and the location of the power unit.
Branch Lines
Branch lines join the remaining inlet valves to the trunk line. As with the trunk line, these lines should be kept as straight as possible. Forty-five degree fittings should be used to avoid sharp corners (90 degree fittings) when possible. Airflow direction should always be considered when installing branch lines.
Avoid Gravity Drops
A branch line is located directly below an overhead trunk line will accumulate dirt due to the effects of gravity. The result will be a pile of dirt at the base of the inlet valve every time it is opened. To avoid this situation, the consult the techniques in the image below.
