Put simply, a thermal store tank is a large, well insulated hot water tank and forms the heart of your home heating and hot water system. A thermal store (or accumulator or buffer tank) stores up heat from a boiler stove or solar panel that can then be used to heat the house and provide domestic hot water whenever it is needed, even if the stove isn't lit or the sun isn't out.
The thermal store also lets you easily link up different heat sources. A classic combination is a woodburning boiler stove (winter heating and hot water), solar panels (summer hot water) and a conventional boiler (to provide a back up). Other sources can also include a ground or air source heat pump, an electrical heating element or a wood pellet stove.
Because you are storing the heat it means that a stove only has to be lit once a day and it can be run efficiently, rather than being kept smouldering all day. The classic cycle is to light the boiler stove in the evening to heat the house and enjoy the fire. All the excess heat is stored in the thermal store. The stove goes out but the heat in the tank is used to warm the house in the morning and provide the domestic hot water. In the afternoon the central heating draws the rest of the heat from the store to warm the house before you return from work and light the stove again.
A good thermal store takes in the source energy efficiently and transfers it back out on demand quickly, maintains good stratification (hottest water at the top, coolest water at the bottom) and, most important of all, minimises heat loss. So the questions that you need to be asking when choosing a thermal store are:
If you are comparing one tank with another then compare the answers to these questions to see if you are really getting value for money.
EnergyStores are the best thermal stores on the market, designed to efficiently store heat from multiple sources with minimal loss to the atmosphere. An Energystore becomes the heart of a renewable heating system ensuring that there will always be heating and hot water whenever the demand is there.
Akvaterm thermal stores are designed to be at the centre of a renewable heating system which would typically incorporate a wood boiler stove and solar thermal panels for the summer. They come in a range of sizes from 300 lt up to 10,000 lt.
These Cordivari thermal stores provide everything from very simple buffers for biomass and wood, to ones suitable for solar thermal, and domestic hot water production. Their removable soft insulation means that they are a bit lower in price, as well as sometimes being easier to get into tight spaces.