Microporous (fumed-silica) panels at 400 °C — heat-loss table

λ = 0.024 W/m·K at mean temperature ((400+20)/2 = 210 °C, from the published curve). Pipe losses per metre, four thicknesses, savings vs bare.

Pipe	30 mm W/m	50 mm W/m	80 mm W/m	100 mm W/m	BARE W/m	Surface @50 mm	Saving €/m·yr @50 mm	t CO2/m·yr
DN25	53	41	32	29	399	30 °C	€175	0.64
DN50	79	57	44	39	720	31 °C	€323	1.18
DN80	105	74	55	48	1,061	32 °C	€482	1.76
DN100	128	89	65	56	1,365	33 °C	€622	2.28
DN150	177	119	85	73	2,009	34 °C	€922	3.37
DN200	223	148	103	88	2,616	35 °C	€1,204	4.41
DN300	317	206	140	118	3,867	35 °C	€1,786	6.54

Assumptions: 20 °C ambient, still air (h=10 W/m²·K combined), €0.05/kWh fuel, 8000 h/yr, 82% efficiency, 0.183 kg CO2e/kWh (DESNZ 2024). Flat surfaces at this duty: bare 3,800 W/m² → 175 W/m² at 50 mm (≈€1,768/m²·yr saved). Method: ASTM C680 simplified — methodology. Your exact case: free calculator.

Context

All materials at 400 °C

Material	λ W/m·K	Loss W/m	Surface	Saving €/m·yr	t CO2/m·yr
Stone wool (mineral wool)	0.067	230	54 °C	€553	2.0
Glass wool	0.064	223	53 °C	€557	2.0
Ceramic fibre (RCF / AES blanket)	0.061	214	52 °C	€561	2.1
Aerogel blanket	0.033	119	38 °C	€607	2.2
Calcium silicate	0.076	261	59 °C	€538	2.0
Expanded perlite	0.079	270	60 °C	€534	2.0
Cellular glass	0.068	235	55 °C	€551	2.0
Microporous (fumed-silica) panels	0.024	89	33 °C	€622	2.3
E-glass needle mat	0.060	208	51 °C	€564	2.1
Silica needle mat / fabric	0.056	197	49 °C	€569	2.1

DN100 pipe at 400 °C, 50 mm insulation, per metre of pipe; bare loss 1,365 W/m. λ at mean temperature; € and CO2 per metre·year at €0.05/kWh, 8000 h, 82% efficiency. Method: ASTM C680 simplified (h=10).

Material datasheet: Microporous (fumed-silica) panels → · temperature class: by temperature →

FAQ

Questions on this topic

How much heat does a pipe at 400 °C lose with microporous (fumed-silica) panels?

With 50 mm at 400 °C (λ=0.024 at mean): DN50 loses 57 W/m, DN100 89 W/m, DN200 148 W/m — vs 1,365 W/m bare for DN100. Full table on this page.

What surface temperature does microporous (fumed-silica) panels give at 400 °C?

≈33 °C with 50 mm on DN100 (20 °C ambient, still air). Personnel-protection targets (≤45–60 °C) may need more thickness — see the 80/100 mm columns.