Short answer: yes
PEX EVOH pipes require insulation in cold environments. The pipe material itself is not freeze-proof. Water inside the pipe will freeze and expand. Example: insulation prevents freezing and bursting.
Freezing risk
Water expands 9% when it freezes. This creates high pressure inside the pipe. The pipe can burst from ice expansion. PEX EVOH pipes are not freeze-proof.
Pipe freeze protection
Insulation provides freeze protection in cold conditions. It slows heat loss from the water. This prevents the water from freezing. PEX EVOH pipes need insulation for freeze protection.
How PEX handles freezing
PEX pipes can expand slightly during freezing. This reduces the risk of bursting. However, freezing still damages the pipe. PEX EVOH pipes are more resistant than rigid pipes but still need protection.
Recommended insulation thickness
Insulation thickness depends on the environment. Cold climates need thicker insulation. Typical thickness is 13-25mm (0.5-1 inch). PEX EVOH pipes require adequate insulation thickness.
Installation depth for buried pipes
Buried pipes must be below the frost line. The frost depth varies by location. Insulation may still be needed for shallow burial. PEX EVOH pipes need proper burial depth.
Heat tracing options
Heat tracing cables can be used for freeze protection. They keep the pipe above freezing temperature. This is an alternative to thick insulation. PEX EVOH pipes can be heat-traced if needed.
Example: residential cold climate
A home in Canada uses PEX EVOH pipes for plumbing. The pipes are insulated in all exterior walls. The water stays above freezing. Example: a safe, freeze-protected system.
Example: commercial building in cold region
A commercial building uses PEX EVOH pipes for heating. The pipes are insulated in unheated spaces. The insulation prevents heat loss. Example: an efficient, freeze-protected system.
Example: underground water main
A water main is buried 48 inches deep. The pipe is below the frost line. PEX EVOH pipes do not need insulation. Example: a safe, protected underground system.
Energy efficiency benefits
Insulation also reduces energy loss. Hot water stays hot during distribution. This saves energy and costs. PEX EVOH pipes with insulation are more efficient.
Final insulation summary
PEX EVOH pipes require insulation in cold environments. The water inside will freeze without protection. Insulation prevents freezing and bursting. Thickness depends on climate and installation. Buried pipes must be below the frost line. Heat tracing can be used as an alternative. Insulation also improves energy efficiency. PEX EVOH pipes need protection to perform reliably. Example: proper insulation for a reliable system.