Expanded perlite at 300 °C — heat-loss table

λ = 0.073 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	108	86	70	64	294	40 °C	€101	0.37
DN50	158	120	94	84	530	44 °C	€200	0.73
DN80	209	154	118	104	782	46 °C	€306	1.12
DN100	253	184	138	121	1,005	47 °C	€401	1.47
DN150	347	246	180	156	1,480	49 °C	€602	2.20
DN200	435	304	218	187	1,927	50 °C	€792	2.90
DN300	616	422	297	252	2,849	52 °C	€1,184	4.33

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 → 356 W/m² at 50 mm (≈€1,192/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: Expanded perlite → · temperature class: by temperature →

FAQ

Questions on this topic

How much heat does a pipe at 300 °C lose with expanded perlite?

With 50 mm at 300 °C (λ=0.073 at mean): DN50 loses 120 W/m, DN100 184 W/m, DN200 304 W/m — vs 1,005 W/m bare for DN100. Full table on this page.

What surface temperature does expanded perlite give at 300 °C?

≈47 °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.