Types of thermal insulation: Thermal insulations are classified as –
1) Organic insulations – e.g. wool (sheep) , cork , cellulose , wood fiber , flax , cotton , hemp , phenolic foam , urea-formaldehyde foam , polyurethane foam , expanded polystyrene foam (thermocol), extruded polystyrene foam , polyethylene foam etc.
2) Inorganic insulations – e.g. aerogel , asbestos , glass wool , slag wool , rock wool , gypsum powder , foamed glass , expanded perlite , refractory bricks , ceramic wool (fiber) ,calcium silicate , vermiculat etc