INSULATING PLASTIC PIPES (CPVC and PEX)
There has been some confusion and misleading statements made in the marketplace regarding insulation requirements when using plastic piping materials such as CPVC and PEX in plumbing and hydronic heating applications. The plumbing, mechanical and energy conservation codes base insulation requirements or thermal efficiency on the type of system (e.g. domestic hot and cold water, hot water heating, and service hot water). These requirements apply regardless of the piping material and are requirements to aid against heat loss within the system. Plastic piping does offer some
increased thermal performance over copper tubing, but neither CPVC nor PEX piping can meet the minimum required thermal performance called out in today’s state, local and model codes.
Based on a the basic requirements for thermal performance of piping systems in the ICC Model Codes, the minimum R-value range is from R-2 up to the equivalent of an R-5 based on the pipe size and system. In the following chart we have calculated the corresponding R-value for PEX, CPVC and Copper using the Cylindrical “R” value Calculation formula which confirms that plastic piping without pipe insulation does not meet the energy conservation code requirements mandated by State, Local , and Model codes