Taking Solar to The Max

Installing a solar thermal system sounds simple enough in theory, but in practice the devil is in the detail and this ultimately dictates its effectiveness. In solar thermal systems, the hot water storage cylinder not only forms an integral part of the system, but also plays a key role in terms of performance and efficiency. As solar thermal systems require a dedicated hot water cylinder, designed to allow maximum transfer of renewable energy into the stored water, it is imperative to look at a hot water and heating system as a whole.

To make life easier for the heating professional, Telford Copper & Stainless Cylinders Ltd have launched a pressurised, sealed, solar thermal domestic hot water package system, which incorporates  a Tempest Solar twin coil hot water storage cylinder. Designed for use with heating systems where solar thermal is used to compliment the main heat source, the easy to install, Solar Keymark approved flat panel solar collectors are capable of providing up to 70% of a households annual domestic hot water requirements. By adopting a package approach, all aspects of the heating system can be designed and sized accurately to meet the requirements of the property whilst operating at optimum efficiencies.

The Duplex stainless-steel cylinders are available in capacities of 170-300 litres and feature a purpose-designed solar coil. This is connected to the solar thermal system and the large surface area allows maximum heat transfer of renewable energy into the stored water. The upper heating coil connects to the boiler as the main heat source, which allows the boiler to heat the top part of the cylinder above the boiler coil. The solar coil works in exactly the same way, but because it is at the bottom of the cylinder, it can heat the whole height of the cylinder.

The cylinder not only needs to be correctly sized to meet the heating and hot water demands of the property, but also to ensure that a minimum dedicated solar volume is achieved. In accordance with the Domestic Heating Compliance Guide, the dedicated solar volume has to be is at least 25 litres per square metre of solar panel area, or 80% of the hot water demand of the household (whichever is the lower). This ensures that energy collected from the solar panels is always utilised. To facilitate this, the design of a solar thermal cylinder is larger and taller than a standard hot water cylinder.