If you have had condensation dripping off chilled water pipework or HVAC ducts and causing corrosion, elastomeric foam is probably the answer. Flexible and closed-cell, it controls condensation so well that it has become the standard in refrigeration and air conditioning. Here is what it does and how to use it properly.
What is elastomeric foam?
Elastomeric foam is a flexible insulation made by expanding synthetic rubber into a closed-cell structure. Because the cells are sealed from one another, moisture cannot penetrate, absorption is negligible, and its inherent vapour resistance makes it strong against condensation. It comes in NBR and EPDM grades, and is also sold under product names such as Atiron.
Key properties
- Service temperature: roughly −50°C to +105°C (by product)
- Thermal conductivity: approx. 0.034–0.040 W/m·K at ambient
- Closed-cell structure — extremely low absorption with inherent vapour resistance
- Highly flexible — fits tightly to bends and small-bore pipework
- Excellent condensation control — the standard for chilled, refrigeration and HVAC lines
- Weakness: vulnerable to UV and ozone — outdoor exposure requires cladding or paint protection
- Forms: pipe covers (tube), sheet, self-adhesive sheet, tape
NBR vs EPDM
| NBR | The most widely used on general heating, cooling and HVAC pipework. Competitively priced. |
| EPDM | Better weather and ozone resistance, giving it the advantage outdoors and under UV exposure. |
| In common | Closed-cell, flexible and condensation resistant — the core insulation for chilled, refrigeration and HVAC service |
| Selection tip | Indoor HVAC → NBR; outdoor or UV-exposed → EPDM, or protective cladding alongside |
Where it is used
- Chilled and cooling water lines — condensation control and insulation
- Refrigeration and cold store pipework — low-temperature insulation
- HVAC ducts and pipework — condensation control and energy saving
- Hot water supply pipework — insulating small bores and bends
- For hygienic environments, consider a dedicated material such as Basofoam
Compared with other insulation
| Elastomeric foam (NBR/EPDM) | The best flexibility and condensation control — suited to chilled, refrigeration and small bores. Weak under UV. |
| Urethane (PUR/PIR) | Rigid sections with low conductivity — suited to straight runs and medium to large bores |
| Glasswool pipe sections | Medium to high temperature (to 350°C) and acoustic — suited to hot pipework, but watch moisture uptake |
| Basofoam | Hygienic, antimicrobial, FDA compliant — suited to cleanrooms, food and pharmaceutical plant |
⚠️Installed exposed outdoors, elastomeric foam cracks and crumbles under UV and ozone. Outdoors it must always be protected with aluminum cladding, a dedicated coating or another facing.
Installation points
- Seal joints and seams completely with the dedicated adhesive — moisture entering a gap causes condensation
- Select thickness on the condensation (dew point) criterion — too thin and the surface condenses
- Never compress it — over-compression reduces thickness and thermal performance
- Insulate continuously with no gaps at valves, bends and other complex points
- Outdoors, cladding or coating protection is essential
💡Tell us the pipe size, service temperature and environment (indoor or outdoor) and we will recommend NBR or EPDM, calculate the condensation-control thickness and quote for it. Enquiries: +82 10-4266-9745
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