Sometimes referred to as Hot Water Tanks, or Hot Water Storage Tanks, Hot Water Cylinders are used as a receptacle to large amounts of water that is kept hot by the boiler. All boilers – except Combi Boilers, which work on a supply-and-demand basis – will use Cylinders.
Insulating your Cylinder is crucial because a well-insulated tank will remain hot for longer, making it more energy efficient, as less heat is lost.
If your Cylinder has not been very well insulated, you can add insulating jackets or blankets that will help to reduce the potential for lost heat. However, you should not feel tempted to add extra insulation to any already insulated cylinder, in the hope of making it more efficient as this could cause more problems. For example, too much insulation could cause condensation to build up which could eventually turn into mould or rust.
Pros of Storing Hot Water in Cylinders:
Cylinders can handle high demands for high water
With Cylinders, there are multiple way in which the water can be heated, other than with a conventional boiler. Green sources, such as Biomass and Solar are also an option that you might consider.
An emergency heat source can be fitted as a backup, offering you insurance should your boiler breakdown. This is especially useful during the winter months.
Cons of Storing Hot Water in Cylinders:
Although large amounts of water can be stored in Cylinders, the amount is still limited, meaning that once it’s empty, it will take time to re-fill and heat up again.
Water in Cylinders is being heated up, even when it is not needed. This can mean that the running costs can get quite high, and it is not always very energy efficient.
Hot Water Cylinders can be quite costly to install.
Due to the on-going temperatures, humidity in the area around the Cylinder is greatly increased. Add to this some slightly damp clothing, and your Airing Cupboard could become a breeding ground for bacteria.
Vented or Unvented?
Hot Water Cylinders come in two forms; either Vented or Unvented, and which one you need is determined by the type of boiler that you use, or intend to use:
Heat Only Boiler: A Vented Cylinder is needed, as it will need to connect to a Cold Water Storage Tank in the Loft.
System Boiler: An Unvented Cylinder can be used, as it does not need to be connected to anything other than the main boiler.
How much water can a Cylinder hold?
How much water a Cylinder holds depends on the overall size, but typically they can hold between 25 to 50 gallons of water.
Choosing the right Cylinder:
Deciding which Cylinder is the right one for your needs will be determined by a few factors:
How much hot water your household needs, on a daily basis
How much space you have for a cylinder; smaller spaces may require a slim line product
You should always consult a qualified Heating Engineer before making any final decisions about purchasing a hot water cylinder.