The Function, Construction And Location Of The Accumulator Tank
An accumulator tank acts as a buffer and intermediate store for water that is pumped around the system. The boiler heats the water in the tank, and the hot water is then supplied to the consumers. When the water in the tank gets so cold that it no longer can meet its requirements, the boiler should fire up and reheat the water in the tank.
This means that accumulator tanks are especially suitable for wood or pellets-fired boilers as there are long pauses between the times the boiler is fired. In addition, the boiler can work at full power and optimum efficiency until the tank is once full of hot water.
A tankless system (direct system) must be started several times per day to maintain heat. Each time the system starts, losses occur, which means that systems containing accumulator tanks are much more efficient that tankless systems. Those who change from a direct system to a system with an accumulator tank experience significant cost reductions! Most accumulator tanks that are sold today are made from metal or a composite material, are cylindrical and come in various heights and diameters. There are also square tanks that are e.g. customised for door apertures’ standard widths. If you want to locate your tank in a space with special dimensions, there are also manufacturers who can build a tank to measure.
In order for heat losses not to compromise economies, it is important that the accumulator tank, pipes and connectors are well-insulated.
A 2,500 litre tank, insulated with 1 cm thick polyurethane and heated to 75 °C, has nearly ten times as many losses as a tank in which the insulation is 10 cm thick.