Stone wool (mineral wool) at 300 °C — heat-loss table

λ = 0.057 W/m·K at mean temperature ((300+20)/2 = 160 °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	87	68	55	50	294	36 °C	€110	0.40
DN50	127	95	74	66	530	39 °C	€212	0.78
DN80	169	123	93	82	782	41 °C	€322	1.18
DN100	205	147	109	95	1,005	42 °C	€419	1.53
DN150	282	196	142	123	1,480	43 °C	€626	2.29
DN200	353	243	173	148	1,927	44 °C	€822	3.01
DN300	501	338	235	199	2,849	45 °C	€1,225	4.48

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 2,800 W/m² → 286 W/m² at 50 mm (≈€1,227/m²·yr saved). Method: ASTM C680 simplified — methodology. Your exact case: free calculator.

Context

All materials at 300 °C

Material	λ W/m·K	Loss W/m	Surface	Saving €/m·yr	t CO2/m·yr
Stone wool (mineral wool)	0.057	147	42 °C	€419	1.5
Glass wool	0.054	140	41 °C	€422	1.5
Ceramic fibre (RCF / AES blanket)	0.060	154	43 °C	€415	1.5
Aerogel blanket	0.029	78	32 °C	€452	1.7
Calcium silicate	0.070	177	46 °C	€404	1.5
Expanded perlite	0.073	184	47 °C	€401	1.5
Cellular glass	0.062	158	43 °C	€413	1.5
Microporous (fumed-silica) panels	0.023	63	29 °C	€460	1.7
E-glass needle mat	0.053	137	40 °C	€424	1.6
Silica needle mat / fabric	0.055	142	41 °C	€421	1.5

DN100 pipe at 300 °C, 50 mm insulation, per metre of pipe; bare loss 1,005 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: Stone wool (mineral wool) → · temperature class: by temperature →

FAQ

Questions on this topic

How much heat does a pipe at 300 °C lose with stone wool (mineral wool)?

With 50 mm at 300 °C (λ=0.057 at mean): DN50 loses 95 W/m, DN100 147 W/m, DN200 243 W/m — vs 1,005 W/m bare for DN100. Full table on this page.

What surface temperature does stone wool (mineral wool) give at 300 °C?

≈42 °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.