Thermal insulation is simply the act of reducing heat transfer between objects in contact which are at different temperatures.It is well known that heat transfer takes place between any two objects in contact so far they possess different temperatures. Heat will flow from the hotter object to the colder object until the two temperatures are the same. Heat transfer takes place in 3 processes namely: conduction, convection and radiation.
In conduction, heat is transferred through solid materials from one end to another without the actual movement of the solids. In convection, heat is transferred in liquids and gases by the actual movement of the liquid or gas molecules. Radiation is the transfer of heat through an empty space. Whenever heat transfer between objects in a space is unwanted, thermal insulation can be used to provide a layer of insulating material to curb or reduce this. The thermal insulating property of a material is measured in terms of its thermal conductivity. A lower thermal conductivity of a material is equivalent to a high insulating capacity. Other important properties to consider in an insulating material are its specific heat capacity and density.
How Heat Escapes From Your Home
Just as explained in the last paragraph, heat transfer takes place through 3 processes of conduction ,convection and radiation. Because your home is built on a rock or cold soil which makes heat flow down into the Earth crust via conduction, you will experience heat loss if it is not properly insulated. Heat is been transferred through solid walls and the roof. The roof tiles and outer walls are warmer than the surroundings. So, the cold air near them get heated up and it flows away by convection. It radiates heat into the surrounding atmosphere like a camp fire in the middle of a large, cold surrounding.
How Thermal Insulation Works
Assuming you pour yourself a hot cup of tea. The 2nd Law of Thermodynamics tells us that it won’t remain hot for ever. What can you do to postpone this inevitability? You just need to stop the heat from escaping by conduction or convection or radiation. The simple thing yo do is to put a lid on the cup. This stops heat losses by convection as a result of hot air ascending and descending above the cup.
You can also decide to surround the hot cup with a layer of air to stop heat from disappearing through the bottom of the cup onto the cold table on which it is placed. You can use a second cup outside the first one to create an air layer or a vacuum between the two to curb conduction. It remains to stop radiation. You can do this by using highly reflective aluminium foils. Wrap these round the outer cup to reflect infrared radiations from the hot tea back inside it. This technique is employed on industrial scales for thermal insulation.
Thermal Insulation in Buildings
As described above, to control the loss of heat in buildings requires the use of special scientific techniques and expertise. Insulation engineers make use of cell layers of insulating materials to achieve this. Polymer and glass can be used to trap air in different kinds of foam-like structures. Reflective foil lamination, fiberglass and rock wool are some of the popular products used in thermal insulation. Use uPVC materials when it comes to replacement windows.
Some benefits of insulating your buildings include:
- Making it more energy a efficient and economical to maintain.
- Providing more uniform temperatures in the building and reducing temperature gradients within the premises both vertically and horizontally.
- Lowering the carbon footprint of your building.
- Helping to reduce noise and undue vibrations.
- Ensuring minimal recurrent expenditure, because insulating is permanent unlike heating and cooling equipment which require regular maintenance.
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