There are essentially three major options for pipe choices for installing a central vacuum: Plumbing Pipe (such as schedule 40 PVC), Flexible Hose, and Vacuum Tubing designed specifically for central vacuums. Herein, please find the advantages and disadvantages of each.
This installation would include standard plumbing pipe that is used in the construction of homes for carrying waste water or even supply water. Generally it has an inside dimension (ID) of slightly greater than 2" (50 mm) and is available in 10 foot or 20 foot (3-7 meter) sections. This is different than standard central vacuum pipe sizes.
This option was attempted in the early 1960's with central vacuums and was soon abandoned as a disaster. This method employs a 2" (50mm) flexible hose in lieu of the fittings and elbows in the system. Currently this flexible hose is only used within the first few feet of VacPan locations to allow for more accurate installation capabilities. The hose currently is available in two styles; one as a vinyl material with a wire reinforcement and the other as a more rigid PVC material. Both exhibit the issues listed below. This is different than standard central vacuum pipe sizes.
This pipe is made specifically for the central vacuum industry and almost all manufacturers adhere to a strict guideline established by American Standard of Testing and Materials (ASTM) Ruling F2158. This standard was developed by pipe manufacturers, central vacuum manufacturers, installers, and consumers as a means to build consistency into the manner that central vacuums are installed. Most municipalities in the USA have adopted this as a part of the Uniform Building Code (UBC) and building inspectors in these regions have a right to reject any central vacuum installation that does not meet this standard or have this value stamped on the pipe and fittings. This pipe maintains a very concise wall thickness and rigidity to allow for maximum airflow through the system.
All central vacuum manufacturers recommend using the proper Vacuum Tubing for very logical reasons.