Deaerator Insulation: Heat Loss & Savings
Deaerators and feed-water tanks hold large volumes of near-boiling water with big bare surfaces, leaking heat continuously even at modest temperatures. Removable insulation cuts that and keeps the surface safe to touch.
Heat loss vs insulated — by surface temperature
| Surface temp | Bare loss | Insulated | Outer surface | Reduction |
|---|---|---|---|---|
| 95 °C | 750 W/m² | 69 W/m² | 27 °C | 90.8% |
| 105 °C | 850 W/m² | 80 W/m² | 28 °C | 90.6% |
| 120 °C | 1,000 W/m² | 97 W/m² | 30 °C | 90.3% |
| 150 °C | 1,300 W/m² | 134 W/m² | 33 °C | 89.7% |
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 |
|---|---|---|---|---|
| A deaerator vessel (8 m², 105 °C) | 6.2 kW | 58 MWh | 11.7 t | €3,364 |
| A feed-water tank (12 m², 95 °C) | 8.2 kW | 77 MWh | 15.5 t | €4,462 |
FAQ
How much heat does a bare deaerator lose?
At 20 °C ambient (ASTM C680): a deaerator vessel (~8 m², 105 °C) loses about 6.2 kW; a feed-water tank (~12 m², 95 °C) about 8.2 kW. Insulating a deaerator vessel saves ≈58 MWh and ≈11.7 t CO₂ per year (8,000 h).
Can you insulate deaerators and similar?
Yes. Deaerators have level gauges, manways and vents needing access. Removable panels lift off locally and refit cleanly. Inzonex covers deaerators, feed-water tanks and condensate receivers. The outer surface drops to a touch-safe ≤45 °C and the part stays serviceable.
How much does deaerator insulation save?
Each item saves up to 96% of its bare loss. A deaerator vessel at 105 °C saves ≈3,364 €/yr of energy (≈58 MWh, ≈11.7 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.