Condensation forms when a surface falls below the dew point of the surrounding air. On chilled-water and refrigeration services, the insulation system must control both heat gain and moisture-vapour movement.
A closed-cell foam contains a network of sealed cells that resists moisture ingress. Correctly specified thickness, well-sealed joints and compatible adhesive help maintain a continuous vapour-control layer around the service.
Good installation remains essential. Gaps, compressed insulation and unsealed penetrations can create thermal bridges that undermine the performance of an otherwise suitable material.