Hot water cylinders are a crucial appliance when it comes to heating systems, they store and heat hot water until it is needed. In the UK, there are two main types of hot water cylinders available: vented and unvented. The type of cylinder you need is heavily dependant on your the type of boiler and heating requirements you have.
Vented vs Unvented Cylinders: What is the difference?
Vented Hot Water Cylinders
These cylinders require a cold water tank, which is usually installed in a loft. The water travels down from the tank to the hot water cylinder. As the water heats up, it expands, which is why vent pipes and the tank offers to store the excess. The hot water is also stored in the cylinder until you need it.
The reason they need to be installed in the loft is becuase they heavily rely on gravity and the higher the cylinder is placed, the more powerful the water pressure is.
Unvented Hot Water Cylinders
When unvented cylinders are installed, heating engineers carefully connect this to the mains. Due to this, you do not require a water in in your loft but alongisde your boiler, creating a stronger pressure for your water. They do not have a tank or vent pipe to take care of the excess when the water heats and expends, which is why they have an expension unit or an air bubble to deal with this.
The greatest advantage for both these cylinders is that they can be heated directly with an immersion heater in the cylinder, by the boiler or even a solar thermal system.
So which one should you choose?
When choosing a cylinder, there are a few things that you need to take into consideration which will help you make your decision. This includes:
- How strong is your existing mains pressure?
- How big is your house?
- How much will is cost to install and maintain?