The thermal conductivity of FLOWGUARD PLUS CPVC pipes and fittings is 0.14 W/MK whereas that of copper is 400 W/MK. Since CPVC is a bad conductor of heat, light insulation is recommended only for installations where there is a continuous flow of hot water e.g. solar/centralized heaters. For bathrooms with independent heaters within 3 meters, insulation may not be necessary. Please ensure that the insulation material or glue used to hold the insulation material is free of any phthalate plasticizer which is not compatible with CPVC and may cause failure within the plumbing system in the long run.