There is a variety of hot water storage cylinders available on the market today, which can be used with solar thermal applications. They are offered in different sizes, types (for vented, unvented or sealed systems) and can be manufactured from both copper and stainless steel.
All solar cylinders feature a purpose-designed solar heat exchanger, which allows maximum heat transfer of solar energy into the stored water. They are suitable for use with wide range of solar systems available in the UK and are efficient and environmentally friendly way of providing Domestic Hot Water.
They are available in direct and indirect versions. Where Solar input does not fully meet the Heating and Domestic Hot Water requirements, direct units have an electric immersion heater to meet the additional load. Indirect units use input from the householders’ traditional heat source of gas, oil or electric boiler to top-up water temperature to the required level.
A buffer tank is integrated into the solar system when additional volume of hot water is required to provide smoother and uninterrupted operation of a heat pump.
Incorporated into a space heating system, the buffer tank increases the volume of water a heat pump has to heat, allowing excess heat to be stored until it is required and reducing the short cycling during normal operation of the heat pump. It also provides a thermal store to aid defrost of the heat pump and protect the water within the system from cooling. As a result it prevents the radiators or underfloor heating from getting colder during the heat pump defrost cycles.
The size of the buffer tank required varies with the size of the heat pump being used. There is a wide range of models in a variety of capacities available on the market to suit different size heat pumps.
Buffer tanks can be manufactured from copper or stainless steel. There are buffers available for use in both vented and unvented (or sealed) systems.
On the market there are now available hot water storage cylinders designed specifically for use with a heat pump.
Most of heat pump cylinders have been specifically designed for use in conjunction with a heat pump as the main source of energy. Featuring a purpose-designed coil, which allows maximum heat transfer of renewable energy into the stored water, those solar cylinders are suitable for use with a wide range of heat pumps available in the UK and are an efficient and environmentally friendly way of providing Domestic Hot Water. Where the input from a heat pump is not sufficient to heat the water to a desired temperature, an electric immersion heater can be used to top it up. Some of the models feature an additional coil for input from traditional gas, oil or electric boilers.
There are also available cylinders for use with heat pump and solar input at the same time. In such cylinders input from a solar thermal system acts usually as a primary source of heat. Where this input does not fully meet the desired temperature a guaranteed quantity of water can be heated to an acceptable temperature by the heat pump and additional immersion heater.
How to choose the right solar cylinder
Choosing the correct size of a cylinder requires a number of factors to be taken in to account. SAP (Standard Assessment Procedure) sets out parameters in terms of the volume of the cylinder which should be dedicated to solar heating only. BS6700 gives guidance on domestic hot water requirements and therefore drives what the required auxiliary volume (via boiler coil or immersion heater back up) of the cylinder should be, as on days when solar gain is minimal, all of the dwelling’s hot water requirement would have to be met by the auxiliary heating.
CenterStore Solar can save on average up to 60% of the annual energy needed to provide hot water. In summer this can be as much as 100% and in winter savings of up to 20% could still be made. The balance of energy required is provided by traditional methods via a gas, oil or electric boiler heating through the cylinder’s auxiliary indirect coil. As an auxiliary back up, every cylinder is factory fitted with an immersion heater.
To benefit from this renewable energy solution, visit our Cylinders section now to view our latest products.