Energy calculator

Design

Kiln interior

Interior dimensions (in)

Unit:

Width

Depth

Height

Target temperature

Operating cone / temperature

Heat loss is computed at steady state with the chamber held at this temperature. Ambient is fixed at 25 °C.

Fire brick

Brick grade

Wall thickness (in)

Insulating firebrick (IFB). Conductivity k(T) rises with temperature — the solver reads it at each layer's mean temperature from Morgan K-IFB data.

Backup insulation

Fibre layers

Per layer (in)

Density grade

Ceramic fibre blanket behind the brick. Set layers to 0 for a brick-only wall. Denser blanket conducts less at high temperature.

Firing method

Heat source

Sets the system efficiency used to turn heat loss into a fuel input rate. Electric puts ~all its input into the chamber; combustion kilns lose a large share up the flue.

Export

Size the elements

The PDF is a printable one-page report. Size the elements carries the interior dimensions to the element calculator.

Wall cross-section & temperature gradient

Power to fire · electric

—

Exterior shell

Where the heat goes

Wall resistance

Results

Calculating…

 Power to fire · electric —  
 Heat loss to hold temperature — steady-state, all surfaces 
 Exterior shell temperature — bare surface, natural convection 

R-values

Fire brick—

Backup fibre—

Total wall R—

Total wall thickness—

Heat transfer

Conduction (through wall)—

Convection (from shell)—

Radiation (ε = 0.9)—

Heat flux q—

Solver residual—

Temperatures

Chamber (interior)—

Brick mean—

Brick / fibre interface—

Fibre mean—

Exterior shell—

Power sizing · electric

Minimum (loss × 1.25)—

Survey — volume (67.6 W/L)—

Survey — surface (0.64 W/cm²)—

Olsen — volume (1.0–1.2 W/in³)—

Olsen — surface (5–7 W/in²)—

Recommended—

Fuel to hold temperature

Electric—

Natural gas—

Propane / LPG—

Wood (dry)—

Steady-state rate to hold temperature. Actual firing consumes far more: the brick mass and the ware must be heated from cold first.