Thermal Store Cylinders
What are Thermal Store Cylinders?
Thermal store cylinders work in the opposite way to traditional & unvented cylinders, in that they do not store hot water that is then delivered directly to the hot water taps. They store water that both the hot water and central heating systems can then draw heat from, when required.
This means that they benefit from there being no need for a cold water storage tank, similar to that of an unvented cylinder. - But there is also no stored water under mains pressure, so they benefit from not requiring as many safety devices as an unvented cylinder does.
They can also have many configurations, being fed by multiple fuel sources, - such as a gas boiler, solar panels, solid fuel, etc.
Positives Of Thermal Stores
1. Mains pressure hot water, with no safety devices required as it is not stored in volume under pressure. 2. No need for cold water storage tanks in loft spaces. 3. Rapid heat up of the central heating system as a large volume of stored heat can be drawn from instantly. 4. Multiple fuel sources can be utilised to contribute towards the store heat.
Negatives Of Thermal Stores
1. Hot water performance is determined by the incoming water main, therefore a 22mm cold water main is usually required for optimum performance. 2. The store cost is usually quite high as they have several heat exchangers, thermostatic mixing valve, etc. 3. The store volume has to be quite large, so as to be sufficient to feed the heating system as well as hot water simultaneously. 4. The stores run at high temperatures to be able to do the above, therefore can suffer accelerated corrosion due to evaporation.