Introduction to Conduction from Bellis

This is the first in a series of blogs on heat transfer and how they relate to insulation products.

Conduction

This is the first in a series of blogs on heat transfer and how they relate to insulation products.  These are fundamental principles that affect everything from keeping LNG tanks cool to your ice cream staying cool in a freezer.  The series will cover conduction, convection, and radiation.

 

Why insulate?

There are many reasons to use insulation.  It can be to stop energy losses from a hot source to the outside world.  It can also be to protect the outside world, be that people or the environment, from hot temperatures.  Cold temperatures in refrigeration units, cold, or cryogenic processes need to be kept cold, so we don’t want heat from the outside air warming these up.

Conduction is defined as heat transfer with no movement of material.  It might be easier to think of this as what happens when you touch a hot coffee cup.  Although none of the hot coffee flows to your hand, you still feel the heat through the solid cup.  This occurs because the energy is transferred into the molecules in the cup, which heat up and transfer heat to the molecules they are touching.  Heat continues transferring from touching molecule to touching molecule until the whole cup feels hot.

Insulating for conduction

Different materials transfer heat at different rates.  If you are cooking on a stove and stirring a pot with a metal spoon, this will heat up faster than a wooden one.  At Bellis we are in the business of minimising heat transfer, so we like materials that conduct heat slowly.  These insulation products are installed around pipes, tanks, exhausts or even pizza ovens to ensure heat does not enter or leave a system.  Products we use include rockwool, Foamglasexpanded foams, ceramic insulations, and aerogels. Good insulating products are generally made from materials that are poor conductors of heat.  Gases and liquids transfer heat through a method called convection, which we will talk about in another blog, but they are poor conductors.  This is exploited by introducing air or gas pockets that are unable to easily flow through the insulation.  In extreme cases a vacuum can be used to eliminate conduction completely; however this does not stop all heat transfer. Do you want to know more about how conduction affects your insulation needs?  Call us today to discuss your problems and we will help you find a solution!