Thermal Stores – Mains Pressure Hot Water Performance Without Unvented Cylinder Restrictions

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Thermal Stores have been an effective and highly efficient hot water solution in the UK for almost 40 years, however, it is a solution which many installers tend to shy away from in favour of the unvented cylinders. No surprise really – sometimes it’s easier just to go with a straight replacement of what’s there or simply revert back to what you know best.

However, thermal store popularity is on the rise, particularly as they overcome many of the frustrations installers have with unvented cylinders, in addition to the hidden costs of installation that are seen as “just part of the job.”

So, why are many installers looking at utilising thermal stores to simplify the installation process and improve the finished solution with a fit and forget hot water alternative?

Sometimes it is out of necessity. For example, in projects where commercial properties are being converted into private apartments and a mains pressure hot water solution is required, it is almost impossible to install the discharge pipework to comply with G3 of the building regulations necessary for unvented solutions. Other times, it proves to be the best solution for the project, such as when incorporating renewable energy inputs or the cylinder/tank needs to be located in a specific part of the home where the space is restricted.

For the smart installers, it is because it just makes life easier with a fit and forget solution that’s less complex to install and requires no ongoing annual maintenance.

Turning the Traditional Approach on Its Head

But how does a thermal store work?

The big tick in the box for end users, housing associations and landlords, is the thermal stores’ ability to provide mains pressure hot water, without the requirement for on-going annual maintenance making them a perfect alternative to the unvented unit.

This is achieved by reversing the traditional approach to hot water.

Instead of storing hot water in the cylinder under pressure, which is then used for taps and showers when required, the thermal store acts more like a battery storing the energy from any fuel source when it is cost effective, and then providing hot water and heating when it is needed in an inherently safe open vented store.

The mains pressure hot water is generated by passing the mains cold water through the highly efficient internal coil. As the hot water is produced instantaneously and not stored, there is zero risk of legionella.

A further benefit to the thermal store over unvented systems is that the domestic hot water is blended at the unit to achieve the optimum temperature of approximately 52 degrees Celsius to avoid scalding when supplied to the taps and showers.

The heating is provided by sending the stored water around the underfloor heating system or wet central heating system.

Simplifying the Installation Process

As the system is not pressurised, it acts much like a vented cylinder and therefore offers so many additional benefits to installers to simplify the install process.

The first big benefit is the ability to site the thermal store anywhere in the property, with no need for complicated discharge pipework and in turn the implications of screeding the pipework under the floor which is required to allow the fall necessary prior to discharging into a high temperature soil stack. This makes them the ideal solution for apartment blocks or in projects where commercial office blocks are being converted into private apartments, enabling mains pressure hot water to be delivered throughout the building.

In addition, the thermal store can be manufactured as a fully bespoke solution, not only when it comes to the tapping positions but also overall dimensions, whether the requirement be tall, short, fat or thin. Unique to thermal stores is the added flexibility of mains pressure hot water supplied from a cube design tank, which means the space requirement can reduce the size by 25% compared to the equivalent cylinder volume.

All this means installers can virtually guarantee they can install a thermal store in the existing space or enable homeowners to move the hot water solution to the attic to free up cupboard space.

As thermal stores are not a pressurised, they do not fall under G3 of the building regulations and therefore do not require your installers to be G3 accredited.

Maximising the Benefit of Low Cost Energy

In these times of ever-increasing energy costs, it is essential to utilise a solution that enable running costs to be kept as low as possible. The thermal store is widely recognised as the optimal solution for utilising energy when supplied at lower cost. In addition, by incorporating multiple renewable energy sources, you can create a truly efficient solution, using for example, solar to capitalise on the energy generated in the summer months with a solid fuel stove generating the power during the colder winter months.

This unique ability to harness the energy as it is generated, store it until it is required and then transfer the heat into heating and hot water on demand, with simplified installation, makes a thermal store the perfect solution for both installers and home owners alike.