How to Choose the Right Pipe Insulation

5 Questions to Answer Before Selecting Pipe Insulation

1. What is the pipe temperature?

This is the primary selection driver. Cold pipes need closed-cell insulation with a vapour barrier. Hot pipes above 105°C need mineral wool.

Temperature Application Material
Below ambient Chilled water, refrigeration, cold water K-FLEX ST/SK (closed-cell)
40–80°C HVAC heating, domestic hot water K-FLEX ST or K-FLEX PE
80–105°C High-temp HVAC K-FLEX ST or Solar HT
Above 105°C Steam, industrial heating K-Rock mineral wool

2. Is condensation a risk?

If the pipe runs below ambient temperature — chilled water, refrigeration, cold water supply — you must use closed-cell insulation with a built-in vapour barrier. Open-cell materials absorb moisture and lose thermal performance. K-FLEX ST and SK are the standard choice — no additional vapour wrapping required. All joints must be sealed with K-420 adhesive.

3. What are the fire safety requirements?

Standard applications: Class O/1 elastomeric is acceptable. Fire-critical areas — plant rooms, commercial risers, escape routes, high-rise buildings over 18m — require non-combustible K-Rock mineral wool with A1/A2 fire rating. Check the project fire strategy before specifying.

4. Indoor or outdoor?

Indoors: standard K-FLEX ST/SK elastomeric or mineral wool. Outdoors: K-FLEX Solar HT (UV-stabilised) or protect standard insulation with aluminium or PVC cladding. Standard elastomeric degrades in sunlight within months.

5. What thickness do you need?

Application Recommended Material Typical Thickness
Domestic hot water PE or Elastomeric 13mm
Domestic cold water Elastomeric (closed-cell) 13mm
HVAC heating Elastomeric or Mineral Wool 13–19mm
Chilled water K-FLEX ST/SK 19–25mm
Refrigeration K-FLEX ST/SK 19–32mm
Heat pump lines K-FLEX ST / Solar HT 13–19mm
High-temp steam K-Rock mineral wool 25–50mm

Installation Notes

Fastest installation: K-FLEX SK self-seal — peel and stick, no adhesive needed.

Complex pipework: Elastomeric tube is flexible and fits around bends and elbows without pre-formed sections. Mineral wool requires pre-formed fittings or on-site fabrication.

Outdoor use: K-FLEX Solar HT is UV-stabilised for external applications. Standard elastomeric degrades in UV without cladding protection.

Sealing: All joints on cold pipe applications must be sealed with K-420 contact adhesive — an unsealed joint is a vapour path to the pipe surface.

Browse all K-FLEX insulation at Airconspares.com →

0 comments

Leave a comment

Please note, comments need to be approved before they are published.