Heat Insulation of Solar Tanks
Heat Insulation
Schematic diagram of a simple solar water heating system.

To minimize the loss of heat during the night the heat insulation of the Storage tank of a solar thermal system is of vital importance. Typical insulation materials are foamed polyurethane, polyethylene or polypropylene, at least 100 mm thick. Alternatively also organic materials made from cellulose or raw wool can be used, demanding a somewhat higher thickness or more layers of insulation to get the same effect.

Since solar storage tanks are thermally stratified – with cold-water layers at the bottom and hot-water layers at the top – many state-of-the-art tanks are assymetrically insulated, meaning an increasing insulation thickness from bottom to top.

Temperatures in the latest generation of water tanks drop less than 3 ° C per day. Through optimal use of insulation, heat loss can be minimised, thereby making effective use of solar heat possible.

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