A thermosiphon is a method of passive heat exchange between the heat source and the heat sink. In the case here the engine is the heat source and the water tank is the heat sink. The fundamental issue when running the Whippet engine in this configuration was it was getting hot and the water was … Read more

Known Parameters for the Boiler Test Object

Barrel shape Boiler Heat Loss Test Object

Before starting the simple modelling I think it is worth looking at the known parameters for the boiler test object. From these there will be some simple assumptions and estimations. Assumptions Lumped point mass. Single temperature measurement represents the temperature of the object. Heat capacity does not change with temperature. Local air temperature represents ambient … Read more

Thermal Conductivity of Wood

thermal insulation of a boiler

In model making and engineering we use wood as a thermal barrier, hence it is good to understand the thermal conductivity of wood. A typical example is in the insulation of a boiler. The thermal conductivity of wood is affected by: density moisture content grain direction structural irregularities temperature Density Plotting the thermal conductivity across … Read more

Boiler Heat Loss Test Object

boiler heat loss test object

My original boiler heat loss test object was a round disc of mild steel and copper. However, this doesn’t relate that well to the actual boiler. This is so that I can test different types of boiler insulation and multi-layer insulation. My original idea for measuring the thermal insulation for the boiler was to make a … Read more

Thermal Insulation of a Boiler

thermal insulation of a boiler

After a few measurements on the vertical boiler, using the cooling curve to estimate heat loss, I achieved a reasonable level of thermal insulation. However, can I turn this into a more methodical approach in the home workshop? I can electrically heat a block of metal, it would be best if this was copper. Copper would … Read more


heating silver steel with blow torch

If a temperature difference exists between two points heat will flow from the point at the higher temperature to the point at the lower temperature. This flow will continue until equilibrium has been reached. The transmission of heat may be due to three different processes. Conduction – This is the process by which heat flows … Read more