Industrial boiler insulation

See the heat. Then the saving.

Most boiler houses lose tens of kilowatts through bare back plates, economizers and valves. We measure it with FLIR, model it in 3D, and show exactly what removable insulation gives back — surface by surface.

FLIR-measured, not estimated ISO 12241 heat loss Up to 96% reduction Surface ≤45 °C
What a bare boiler costs

Bosch package boiler — three surveyed surfaces

Bare heat loss
5.7 kW
Front door, burner flange, valves
Hottest surface
190 °C
Steam valves, FLIR
After insulation
0.28 kW
≈95% cut, ≤45 °C surface
Saved per year
≈49 MWh
≈ €2,969 across the three

From a real FLIR survey of a Bosch package boiler. CAD surface areas uplifted ×1.4 for bolts and irregular geometry; ISO 12241 steady-state, 50 mm modular core. These are the three quantified surfaces — the rest of the boiler-house feed and steam set adds to this.

Start with a 3D model

Pick a boiler, then walk its surfaces

Each model is built from our own CAD and a real thermal survey. Rotate it, toggle bare vs insulated, and open a measured page for every surface.

Live Bosch package boiler 3D model
Bosch · package steam boiler

Bosch boiler

FLIR survey + 3D model — front door 96 °C, burner flange 146 °C, steam valves 190 °C. Three quantified surfaces, 5.7 kW bare → 0.28 kW insulated.

Open 3D model →
 Live Cochran shell boiler 3D model
Cochran · shell steam boiler

Cochran boiler

6 surveyed views, 28 measured components — back plate, economizer, valves, feedwater set. 49.8 kW bare → 2.6 kW insulated.

Open 3D model →
Bosch boiler · surface by surface

Every view is its own measured page

This is the hub. Each surveyed surface becomes a page that answers a real engineering question with FLIR temperatures and ISO 12241 heat loss — then links back here.

Bosch boiler front door and burner flange

Front door & burner flange 146 °C

● Live page

Door 96 °C + burner flange 146 °C — 4.3 kW bare.

 Bosch boiler steam valves

Steam valves 190 °C

● Live page

Hottest surface — 1.4 kW bare, cut ~95%.

 Bosch boiler top fittings

Top & feedwater survey

○ Pending data

Built when the per-surface FLIR + CAD areas are confirmed.

 Bosch full 3D model

Full model 3D

● Live

Rotate, toggle bare/insulated, jump to any surface.
The engineering

How a steam boiler loses heat — and where

A package boiler running at 6–10 bar sits at a saturation temperature around 165–185 °C. Every bare surface at that temperature is a continuous heat pump into the boiler-house air. Three mechanisms move that heat — and standards exist to quantify each.

Convection

Bare steel hands heat to the air touching it; the slightest draught in a real boiler house (≈0.5 m/s) raises the loss well above the still-air textbook value. We model that velocity, not zero.

Radiation

At 120–180 °C a large share leaves as infrared, independent of air movement. We add explicit radiation (ε≈0.9 for bare steel), which a single lumped coefficient understates on hot surfaces.

Where it concentrates

Valves, flanges and the burner door — the large or awkward shapes a standard jacket skips. On the surveyed Bosch the steam valves alone hit 190 °C, the hottest surface on the boiler.

Method: ISO 12241 / ASTM C680 steady-state, convection at 0.5 m/s plus explicit radiation. “Touch-safe” means a clad surface at ≤45 °C (ISO 13732-1 contact-burn guidance for metal). These are the same equations behind every number on this site.

Best practice

How to insulate a boiler house — in order

The first step is never rip-and-replace. It is closing the bare spots a standard jacket leaves behind, on the surfaces that pay back fastest.

  1. Survey, don’t guess. A FLIR pass finds the real hot spots and their temperatures — the basis for any honest number.
  2. Start with the economizer and back plate. Largest area × highest temperature = fastest payback, and the surfaces most often left completely bare.
  3. Then the steam fittings. Valves and flanges run hottest (~180 °C) and lose the most per m²; removable covers insulate them yet still open for inspection.
  4. Insulate access points removably. Manholes, burner doors, strainers and blowdown must stay serviceable — fixed lagging gets cut off and never returns, so use buttoned panels.
  5. Leave safety-critical parts clear. Safety-valve lift, drain and discharge stay uncovered; only the body and standing pipe are insulated.
  6. Verify touch-safe. Target ≤45 °C clad surface — confirms both the energy saving and the removed burn hazard.

Up to 96% heat-loss reduction on a fully clad surface; surface temperature ≤45 °C; payback typically under two years. UK patent application GB2508992.1.

Why it fails

Three failure modes — one access problem

In a boiler house the hottest surfaces are the ones engineers open most — doors, valves, pumps, manways. Traditional insulation blocks that access, gets stripped off to service the equipment, and rarely goes back. The high heat-loss components stay permanently exposed.

Sagging soft insulation blankets collapsed away from the surface
01 · Sagging soft blankets

Lose contact with the surface

Wraps collapse inward and lose contact with the surface. Hot spots grow inside — unnoticed.

Aluminium cladding boxes cut open with degraded mineral wool
02 · Aluminium boxes skipped

Cut open, never reinstalled

Cut open for every inspection. Heavy, rigid, and rarely reinstalled — so the surface stays bare.

Bare boiler door, never insulated because nothing off-the-shelf fits
03 · Never insulated

Nothing off-the-shelf fits

Boiler doors, manways and pump bodies — nothing off-the-shelf fits.

The Inzonex answer

Engineered to fit, fasten and serve

One access problem, solved. Three details that let modular removable insulation keep performing on boiler-house hot surfaces — doors, valves, pumps and manways — year after year.

Stainless snap-button fastening on an Inzonex removable cover
Easy installation · Snap-button fastening

Opens by hand in seconds

Stainless snap buttons fasten and release each cover by hand — no tools, no fixings drilled into the equipment. Covers go on fast at install and unclip in seconds for valve operation, manway access or inspection, then snap back exactly.

Zip-out mineral-wool core of an Inzonex cover
Serviceable · reliable · Zip-out core

Renew the core, keep the cover

The cover unzips so the mineral-wool core lifts out — to clean the outer fabric or renew the insulation without scrapping the whole cover. The shell stays in service; only the core is replaced, so the cover lasts for years.

Form-fitting modular insulation following equipment geometry
Modular · form-fitting

Follows the equipment's shape

Modular sections connect to one another and wrap the exact geometry — boiler doors, valves, flanges and pump bodies — minimising creases and gaps that leave hot bridges or let moisture sit. The tailored fit holds the surface ≤45 °C and survives repeated access.

From surface to saving

Take any number further

Calculator

Your boiler house

Boiler count, fuel price, hours → energy, £ and payback.

Open calculator → Carbon

Heat → CO₂ → EU ETS

Turn bare-surface kilowatts into tonnes and carbon cost.

Carbon hub → All tools

Calculators & studies

Pipe, brewery, laundry and whole-plant heat-loss tools.

See calculators →