The method is one method across the whole section. Surface temperature is measured with a radiometric thermal camera; area is rebuilt in CAD from the surveyed machine; heat loss is then calculated to ISO 12241 from those two. Nothing here is metered heat, and no boiler efficiency test was carried out.
Boilers/This page
| Setting | Value |
|---|---|
| Camera | FLIR S62 Pro, full radiometric |
| Emissivity | 0.90 |
| Reflected temperature | 25 °C |
| Atmospheric temperature | 25 °C |
| Relative humidity | 50 % |
| Distance | 3 m |
| Stated accuracy | ±2 °C or ±2 % |
| Standards | ISO 18434-1, ASTM E1933 |
Temperatures are recomputed per pixel from the raw thermal matrix embedded in each file together with its Planck constants, using exiftool and raw2temp. Full-field values agree with the camera’s own on-image spot markers to about 1 °C.
Emissivity 0.90 is the value used for painted and oxidised steel on these machines. A polished or bare metallic surface would need a different value, and none of the surveyed surfaces were polished.
Every component is rebuilt in CAD from the surveyed machine and its outer surface area is read off the model. An allowance is then added, because bolts, nuts, weld seams and irregular surface all enlarge the area that actually radiates and convects.
| Where | Allowance | Why that figure |
|---|---|---|
| Cochran and Bosch UL-S surface pages | ×1.4 | Views dominated by flanged and bolted assemblies, where the fitting is far from a smooth box |
| Bosch measured case | +12 % | Three components rebuilt individually, so the model already carries most of the shape |
An allowance is not a measured area. Where a page gives an area it states which allowance is in it, and the CAD base area is the figure before that allowance.
Heat loss is calculated to ISO 12241 and ASTM C680, steady state, with forced convection at an air velocity of 0.5 m/s and radiation stated separately. The measured surface temperature is the boundary condition; the modelled area is the second input. That is the whole chain.
The insulated case is computed the same way, with the module in place and the outer surface at or below the 45 °C touch-safe design target, assessed to EN ISO 13732-1.
This is a calculation, not a measurement of heat. No heat flux meter was used, no fuel meter was read and no steam flow was logged.
| Input | Section planning default | Where a case differs |
|---|---|---|
| Hours | 7,700 h/yr | Cochran laundry case 5,840 h/yr |
| Boiler efficiency | 0.90 | Bosch case 0.85, Cochran laundry case 0.88 |
| Fuel price | 60 €/MWh | Same, stated per page |
| CO₂ | 201.6 kg/MWh | Bosch case 0.20 kg/kWh |
Each measured case keeps the basis it was published with, so a figure on a case page and the same machine inside a section total can differ. Where that happens the page says which efficiency is in the number.
Fuel input, steam output, feed water chemistry, total dissolved solids, blowdown rate, flue gas analysis and plant-room air exchange were not measured on these surveys. Where a figure for one of those appears anywhere in the section it is either taken from the site’s own records, and said to be, or it is an estimate, and said to be.
Positions on the schematic drawings are indicative: no layout drawing was surveyed. The drawings show what an item is and what it reads, not where it sits to the millimetre.
Four things go into a watt: a surface temperature, an area, the air around the surface and a standard. Each is read or named, and none is assumed.
Steam output, fuel input and flue gas temperature were not measured by Inzonex on these machines, and no efficiency percentage is quoted for them. What is published is the loss from the outside of the metal.
Calculated. The surface temperature is measured with a radiometric thermal camera; the area is modelled in CAD; heat loss follows from those two by ISO 12241. No heat flux meter was used.
0.90, the value for the painted and oxidised steel found on these machines. None of the surveyed surfaces were polished metal, which would need a different value.
It is a geometry allowance for bolts, nuts, weld seams and irregular surface, applied to the CAD base area. It is not a measured area, and the Bosch case uses +12 % instead because those three components were each modelled individually.
Because each measured case keeps its own published basis. The Bosch case is computed at 0.85 boiler efficiency, while section totals use the 0.90 planning default. Both are stated where they are used.
Fuel input, steam output, water chemistry, blowdown rate, flue gas analysis and air exchange. Nothing in this section is a boiler efficiency test.
ISO 12241 and ASTM C680 for the calculation, ISO 18434-1 and ASTM E1933 for the infrared work, and EN ISO 13732-1 for the contact-burn assessment.
The surveyed view this page came from, with every element on it.Open
→/ 02Where the surface loss sits inside the indirect method.Open
→/ 03Six surveyed views, 28 components, 49.8 kW bare.Open
→| Survey | FLIR S62 Pro, emissivity 0.90, reflected 25 °C, 3 m, full radiometric correction. UK commercial boiler house. |
| Geometry | Rebuilt in CAD from the surveyed machine. Area allowances are stated on the page they are used on and are allowances, not measured areas. |
| Calculation | ISO 12241 steady state. Heat loss is calculated from the measured surface temperature and the modelled area — it is not metered. Full method, basis and limits. |
Where surface loss sits inside the indirect method, and what 49.8 kW is against the fuel input.Open
→/ 02What has to be opened, how often, and who signs it off under PSSR 2000.Open
→/ 03Which machine this is, and why the losing surfaces differ between the two.Open
→