Payback = installed cost ÷ annual saving. Annual saving = (bare loss − insulated loss) × hours ÷ boiler efficiency × fuel price — plus, increasingly material, × carbon price for ETS-exposed sites. Example from this site's tables: one bare DN150 valve at 250 °C ≈ 1,050 W; a removable cover cutting ~90% saves ≈9,200 kWh fuel/yr ≈ €460 at €0.05/kWh, plus ~1.7 t CO2 ≈ €130 at the EU ETS price — so a few-hundred-euro cover pays back well inside two years. The free calculator and the Carbon Savings Certificate tool automate exactly this arithmetic.
Compute your own case: free heat-loss calculator · materials library: 12 datasheets · related: What is CUI (corrosion under insulation)? · What is economic thickness of insulation? · R-value vs k-value (λ) — what's the difference? · What insulation works at 600 °C?
