Insulation is not just used for containing heat. It is also used to control cold pipe systems and keep them functioning properly and in good repair.
There are several issues to be dealt with when using insulation jackets on cold pipe systems. The first and possibly most important concern is controlling condensation. When the cold pipe system contacts the air, condensation will form once the pipe system is below the dew point of the ambient air. This condensation can aversely effect the quality of the pipes and cause mould, ice, and degradation of the pipe material.
Cold insulation jackets need to be specially designed with sufficient thickness and vapor retardation qualities to keep condensation from gathering. Condensation causes corrosion of metal and decreased efficacy of the insulating materials in the jackets.
Insulating Cold Pipes vs. Hot Pipes
It is a common misconception that cold insulation materials can be the same as insulation for hot systems. In reality, there are several differences between cold system insulation needs and hot system insulation needs:
- Closed cell structure: Closed cell structure is necessary to avoid wicking behavior. Most open celled material used for high temperature systems allows water to enter because the heat will cause the moisture to evaporate before it can corrode the metal. This same moisture ingress is very detrimental to cold systems because the moisture does not evaporate.
- Effective Water Vapor Barriers: Preventing condensation from gathering directly on the metal surface being insulated a key part of avoiding metal degradation. A solid, flexible water vapor barrier is necessary to prevent water from condensing on the metal pipe surface. This type of water vapor barrier is not necessary for hot systems.
- No Thermal Bridging Potential: Often, there are strangely shaped or bent connections that are left un-insulated because their size and shape make them hard to find insulation for. Examples include expansion joints, triple duty valves, and flange sets. These types of joints are potential thermal bridge points if left un-insulated. In cold systems, they will collect moisture. Bendable or flexible insulation is needed to protect against this.
Cold Pipe Insulation Materials
There are several types of materials that can be used to insulate cold systems. When combined with the appropriate vapor barriers, materials like fiberglass, mineral wool and cellular glass are rated for low temperatures. Because of their flexible and closed-cell nature, foam polyurethanes are also popular for insulating cold pipe systems. There are many types of flexible and rigid insulation techniques for cold pipe systems that involve a number of variations in materials used.
Ideal Cold Pipe Insulation Characteristics
- Strong vapor barrier capability
- Closed sell, non wicking components
- Air tight application
Often, materials that include all of these characteristics have one major drawback. Getting to the actual pipe surface for maintenance purposes often involves damaging or permanently removing the insulation that was applied. This can get rather expensive, especially if the area that needs to be reached is a valve that needs to be freely accessible. There are several options of removable insulation for cold pipe systems that make reaching these areas easier and less costly.