A hot water cylinder is heated either directly or indirectly, primarily using electricity or heat from a boiler.
Here's a breakdown of the heating methods:
1. Direct Heating (Electric Immersion Heater):
- In this method, the water inside the cylinder is heated directly by an electric immersion heater located within the tank.
- The immersion heater is essentially a large resistor that heats up when electricity passes through it, warming the surrounding water.
- Modern direct cylinders often feature "smart" immersion heaters that can optimize energy usage.
- Example: A Kingspan Albion Ultrasteel direct cylinder heats water directly using an electric immersion heater.
2. Indirect Heating (Boiler or Other Heat Source):
- In this method, the water inside the cylinder is heated indirectly by a separate heat source, typically a boiler (gas, oil, or solid fuel).
- The boiler heats water, which then circulates through a coil or heat exchanger inside the hot water cylinder.
- As the hot water from the boiler passes through the coil, it transfers its heat to the water in the cylinder, without the two water supplies mixing.
- Once the water in the cylinder reaches the set temperature, a thermostat stops the heating process.
- This method is common in homes with central heating systems.
Summary Table:
| Heating Method | Heat Source | Mechanism | Advantages | Disadvantages |
|---|---|---|---|---|
| Direct Heating | Electric Immersion Heater | Electrical resistance heats water directly. | Simple installation, independent of other systems. | Can be more expensive than indirect heating, reliant on electricity supply. |
| Indirect Heating | Boiler (gas, oil, solid fuel) | Boiler heats water that circulates through a heat exchanger. | Often more energy-efficient, utilizes existing central heating system. | Requires a separate boiler system, can be more complex installation. |
Therefore, hot water cylinders are heated using either direct electrical heating or indirect heating from a separate heat source like a boiler.
