BOILERS / METHOD / COMPARISONS
Boiler surface heat loss: surveyed components compared
Based on the published Boilers surveys and model outputs. Read the source scope alongside each comparison.
Published inputs and what they mean
| Surveyed surface | Metal °C | Modelled area m² | Calculated bare W | Bare W/m² |
|---|---|---|---|---|
| Bosch UL-S front door | 96 | 2.33 | 2,530 | 1,086 |
| Cochran feed pump | 100 | 1.49 | 1,664 | 1,117 |
| Cochran front door | 120 | 5.32 | 7,973 | 1,499 |
| Cochran economiser | 126 | 11.31 | 18,327 | 1,620 |
| Cochran end plate | 130 | 5.32 | 9,063 | 1,704 |
| Bosch burner flange | 146 | 0.85 | 1,780 | 2,094 |
| Cochran check valve | 180 | 0.90 | 2,599 | 2,888 |
| Bosch steam valves | 190 | 0.45 | 1,430 | 3,178 |
Cochran and Bosch are separate surveyed installations. These rows are not a controlled manufacturer comparison. Temperature, shape and component scope differ. W/m² separates the effect of area from total loss, but does not remove temperature or geometry effects.
The Cochran economiser contributes 18,327 W over 11.31 m². The Bosch burner flange contributes 1,780 W over 0.85 m². The flange has higher loss per square metre; the economiser is the larger total opportunity. Prioritise total recoverable heat together with access, coverage and installed cost.
Doors at their surveyed conditions
The Cochran door is 5.32 m² at 120 °C and 7,973 W bare; the Bosch UL-S door is 2.33 m² at 96 °C and 2,530 W bare. Their different total losses do not establish a difference in boiler efficiency. Neither figure represents the entire boiler.
Source rows: Cochran door, Bosch door and flange, Cochran end plate and economiser, feedwater surfaces, Cochran steam fittings and Bosch steam fittings.