Exhaust & Manifold Insulation: Heat Loss & Savings
Engine and genset exhausts run very hot and radiate heat fast — left bare they overheat enclosures and endanger workers. Removable high-temperature exhaust insulation cuts the loss, lowers engine-room temperature and brings the surface touch-safe.
Heat loss vs insulated — by surface temperature
| Surface temp | Bare loss | Insulated | Outer surface | Reduction |
|---|---|---|---|---|
| 300 °C | 8,075 W/m² | 204 W/m² | 34 °C | 97.5% |
| 400 °C | 14,273 W/m² | 321 W/m² | 41 °C | 97.8% |
| 500 °C | 23,410 W/m² | 461 W/m² | 50 °C | 98.0% |
| 600 °C | 36,423 W/m² | 624 W/m² | 60 °C | 98.3% |
Per-m² flat-surface flux, ASTM C680 / ISO 12241, 50 mm Lamella (≤220 °C) or 100 mm Wired mat (>220 °C), 20 °C ambient. Multiply by the bare area.
Worked examples (per year, 8,000 h, natural gas)
| Item | Heat saved | Energy/yr | CO₂/yr | € saved/yr |
|---|---|---|---|---|
| An engine exhaust manifold (2 m², 450 °C) | 36.1 kW | 339 MWh | 68.6 t | €19,686 |
| A genset exhaust run (4 m², 400 °C) | 55.8 kW | 525 MWh | 106.1 t | €30,465 |
FAQ
How much heat does a bare exhaust & manifold lose?
At 20 °C ambient (ASTM C680): an engine exhaust manifold (~2 m², 450 °C) loses about 36.1 kW; a genset exhaust run (~4 m², 400 °C) about 55.8 kW. Insulating an engine exhaust manifold saves ≈339 MWh and ≈68.6 t CO₂ per year (8,000 h).
Can you insulate engine and genset exhaust manifolds and similar?
Yes. Exhaust joints and sensors need inspection and the parts vibrate. Removable exhaust wraps take the movement and come off for service. Inzonex covers engine and genset exhaust manifolds, turbochargers, silencers and exhaust pipe runs. The outer surface drops to a touch-safe ≤45 °C and the part stays serviceable.
How much does exhaust & manifold insulation save?
Each item saves 96–98% of its bare loss. An engine exhaust manifold at 450 °C saves ≈19,686 €/yr of energy (≈339 MWh, ≈68.6 t CO₂) at typical gas prices; payback is usually under two years.
What insulation thickness is used?
Up to 220 °C surface: 50 mm mineral-wool (Lamella); above 220 °C: 100 mm (Wired mat), because conductivity rises with temperature. Both keep the outer surface ≤45 °C.