Brewhouse vessel roof before insulation
Brewhouse vessel roof with Inzonex Modular Insulation
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Insulatedouter face 27.5 °C
Baresurface 68 °C
At 68 °C  ·  24.0 kW bare  ·  1.3 kW insulated  ·  27.5 °C outer face
Inzonex
Mash tun Inzonex Modular Insulation · 68 °C surface · ISO 12241 model
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Details · heat · surface · sections · calculate
Typical losses · Mash tun

Heat loss before and after insulation

Bare surface loss24.0 kW615 W/m² at 68 °C
With Inzonex1.3 kW50 mm mineral wool
Reduction94.6%of casing heat loss
Outer face27.5 °Cdesign target ≤ 45 °C
Heat retained149.9 MWhper year
Estimated cost saving£7,97429.5 t CO₂e avoided

The calculation covers surface heat loss only: convection and radiation from the shell, with conduction through the insulation. Heat carried away as vapour is a separate loss and is not included. Emissivity is 0.90 bare and 0.85 on the insulated face. Cost uses fuel at 94 % heat-supply efficiency and 185 kg CO₂e per MWh of fuel. The surface is treated as flat area: thermal bridges, fixings, dome curvature and gaps are not resolved separately.

Surface heat loss at 68 °C

Mash tun holds the mash through each rest. While it is working the shell is at about 68 °C. On the inputs above the calculated surface loss is 24.0 kW.

With Inzonex Modular Insulation over the same area the calculated loss is 1.3 kW, which is 94.6 % lower. At 6,600 operating hours a year that is 149.9 MWh of heat retained.

The calculation covers surface heat loss only. Heat carried away as vapour is a separate loss and is not included. The 3D model is the kettle geometry; all five vessels are calculated on the same starting area, each at its own surface temperature.

Per vesselBareInsulated
Surface heat loss24.0 kW1.3 kW
Surface temperature68 °C27.5 °C
Heat retained / yr—149.9 MWh
Fuel equivalent / yr—159.5 MWh

q = h(Ts − Ta) + εσ[(Ts+273.15)⁴ − (Ta+273.15)⁴], with h = 5.7 + 3.8v W/m²K. Conductivity is taken as λ = 0.031 + 0.000188 × mean layer temperature, W/mK, evaluated at the solved mean layer temperature. Certified λ curves differ between products.

Calculated outer-surface temperature

With 50 mm of mineral wool the calculated outer surface is 27.5 °C. The design target for surfaces people work next to is 45 °C. The calculated heat released into the brewhouse falls from 24.0 kW to 1.3 kW.

Inputs: 50 mm mineral wool, air 25 °C at 0.5 m/s, emissivity 0.90 bare and 0.85 on the insulated face, bare surface 68 °C. Area, temperature and hours are editable in the calculator above.

Calculation inputValue
Insulation thickness50 mm
Ambient air25 °C
Air speed0.5 m/s
Emissivity, bare / insulated0.90 / 0.85
Operating hours6,600 h/yr

Removable sections

The insulation is made in separate sections around the manway, the instruments and the stack connection. Each section can be removed separately for inspection or maintenance and refitted afterwards. Vents, safety devices and required clearances stay unobstructed.

No access-time saving is included in this calculation.

Stays accessibleHow
Manwayown section
Instrumentsown section
Stack connectionown section
Vents and safety devicesleft clear

Estimated annual energy and cost savings

Reference case: one vessel, 39 m², 68 °C bare surface, 6,600 operating hours a year. The retained heat is valued at £7,974 a year at £50/MWh of fuel and avoids 29.5 t CO₂e.

Natural gas at £50/MWh, 94 % heat-supply efficiency and 185 kg CO₂e per MWh of fuel. Enter the site's area, temperature, operating hours and fuel price to recalculate the results.

Open the Mash tun calculator →

Per yearReference case
Estimated energy cost saving£7,974
Heat retained149.9 MWh
Fuel equivalent159.5 MWh
Emissions avoided29.5 t CO₂e

The surface is treated as flat area: thermal bridges, fixings, dome curvature and gaps are not resolved separately.

Questions

Frequently asked

Which temperature should I use for a mash tun?

The example starts at 68 °C on the bare metal surface. Mash temperature and outer metal temperature need not be equal. Measure the area you plan to insulate during operation, and use separate saved scenarios for surfaces at different temperatures.

How is heat loss calculated?

For each square metre, bare heat loss combines convection and radiation: q = h(Ts − Ta) + εσ[(Ts + 273.15)⁴ − (Ta + 273.15)⁴]. The convection coefficient is estimated as h = 5.7 + 3.8v W/m²K, where v is air speed in m/s. The insulation calculation balances conduction through the layer against heat released from its outer surface. Conductivity is approximated as λ = 0.031 + 0.000188 × mean layer temperature, in W/mK. This conductivity curve is an assumption; check it against the selected insulation’s certified data. Heat retained per year = (bare kW − insulated kW) × operating hours ÷ 1,000. The calculation uses a flat-area approximation and does not separately resolve thermal bridges, fixings, dome curvature, gaps or temperature changes during a batch. Validate coverage, temperatures and material properties for a project estimate.

Is retained heat the same as a gas saving?

No. Retained heat is energy no longer lost through the modelled surface. For a fuel-fired heat supply, the fuel equivalent divides that heat by the heat-supply efficiency. This assumes the heat supply controls reduce input accordingly. A boiler nameplate efficiency alone may not include steam distribution losses. Use a consistent net or gross calorific basis for efficiency, tariff and emissions factor. The estimate does not include evaporation, flue-gas losses, batch throughput gains or measured changes in burner consumption.

Do the rendered views change with the calculator inputs?

No. The six camera angles are design renders for comparing bare metal with PTFE-faced or silicone-faced Inzonex insulation. Changing the inputs updates the calculation, not the renders. Confirm equipment dimensions and surface temperatures with a site survey.

What should I check before ordering?

Confirm the area, surface finish, measured temperatures, operating hours and access requirements. Use your energy tariff and an installed quotation for payback. The calculation covers surface heat loss only; it excludes maintenance savings and changes in equipment life or room temperature. The 45 °C outer-surface value is a design target, not a universal safe-touch guarantee. Actual contact conditions, joints and exposed parts need a site-specific check.

Inzonex Modular Insulation · survey-based engineering