Are you going to dump your old hot water storage cylinder and you are asking yourself which style do you require?
Or are you looking to have a brand new one put in place next to a system or regular boiler?
Regardless of your situation the language used might sound quite unfamiliar to many, therefore in this guide, we will help you understand all the fundamental concepts you should be aware of.
What is a Hot Water Storage Cylinder or how does it work?
A hot water storage cylinder is as the name suggests a water storage tank that is designed to store larger volumes of the hot water intended for particular forms of the boilers and central heating systems.
It is used to store hot water to be used to provide hot water to the water outlets which include your shower and taps.
Generally, the hot water tank hardly fits an airing cupboard together with other items but can equally be fitted in garages and attics.
Needless to say, not all types of domestic heating and hot water systems have a cylinder, such as if a combi boiler is in use, the hot water is instead, heated as and when it is required.
Different types of Hot Water cylinders
In the same way that there are different forms and styles of boilers, there are also different forms and styles of hot water storage cylinders and it is vital to understand that the one best suited to your home will depend on various factors.
This mainly includes the following two factors:
- Your present and future needs in hot water
- The type of boiler installed in your property.
Direct and Indirect Hot Water Storage Cylinders
Direct and Indirect Hot Water Storage Cylinders
Direct type hot water storage cylinder has a capability to heat the water itself and is commonly known as immersion heater.
Similar to hot water kettles you are likely to find in any kitchen today, they function in the following manner. Inside they have a large heating element consisting of a metallic coil which when had by electrical voltage transmits heat to water sitting on the tank hence warming the water contained therein.
The water is then supplied to the water outlets for instance taps when they are on. Usually an immersion heater must be switched on several hours before hot water is needed thus they are often used together with a timer.
Non-pressurized, or Indirect HWSC
There is the direct heated type of hot water storage cylinder and the other type is the indirect heated cylinder. On the other hand, indirect cylinders use some other source to heat this water before actually storing it in the cylinder.
These can also be a domestic boiler which will heat the water with a help of a heat exchanger or Renewables such like the solar panels. The cold water gets conducted into the cylinder from a source of water. This can be a different water tank, or can be fed from the mains water supply directly as well.
The storage tank provides a heat exchanger, usually a metallic coil through which the water from the boiler passes thereby heating up the water in the indirect hot water cylinder. After the water has passed through the coils, it drains into the boiler, and is pumped back again in order to do the cycle once more.
When the water passes through the heat exchanger, it warms the water inside the cylinder; because heat rises the hot water is the one at the top of the tank nearest to the outlet to the home’s pipe work. The cold water is fed at the bottom of the tank where the heat exchanger is meaning that the water is kept warm.
Vented & Unvented Hot Water Storage Tanks
Unvented Cylinders
An unvented cylinder is normally connected to the mains water supply, and therefore operates under high pressure, or with a good water pressure.
For this reason, they do not have the need for a cold-water storage tank and they can also be tied into an existing heating systems pipework making it possible to install them almost anywhere.
Normally unvented cylinders are made from stainless steel and this has the advantage of heat retention compared to copper that is also use to make the cylinders. They also tend to last longer than copper, this is perhaps one of the reasons why many of the recycled products are made of iron.
Unvented cylinders are mostly installed together with a system boiler and this component is one of their biggest advantages because they do not need a header tank in the attic and because of this they occupy very little space.
Vented Cylinders
This is a cylinder that is fed directly from a cold water tank which is usually located in the loft, also called feeder tank. This is done in the cylinder by filling the unit with water with the assistance of gravity from a vented pipe and is also heated in a similar manner and supplied to the water outlets via the pipework.
Such adaptations include the vent pipe that provides room for the water expansion when it gets into the tank in addition to a way that safely transforms the remaining water into condensation that can be added to the cold tank.
As this system depends on gravity to provide water to the tank, the cylinder must be placed directly below the cold water tank. This also means that water pressure can be low, it becomes sometimes hard to shower and therefore extra pump can be used to increase water pressure.
Traditionally, the cylinders are of grade 3 coppers and are predominantly applied together with the conventional system.
Which Type of Cylinder is Right for Your Property?
Here are some other factors that are important to consider:
- Vented cylinders are rather appropriate for the properties that still have old heating systems that cannot manage high pressure of mains water. The installation costs are also usually low and the initial costs of the cylinder too are considerably low.
- On the other hand, unvented cylinders do not need a cold water storage tank and as such do not need as much room in which to install and where they can be installed is more accommodating. As they are connected to the mains they also offer much more powerful water jets.
- However, it is important to note that it is always a winning factor that in the case you are locked out of the main water supply, you can still be using vented cylinders.
- It is also worth considering your current heating system, for instance, the system’s age. If it is an old system, then it may not be able to withstand pressure coming from the mains hence a vented cylinder is preferred.
- Likewise if the water pressure is low in your mains, it would not be feasible to have an unvented cylinder which has a high pressure requirement. You still can, but the pressure may require boosting by putting in a pump to increase pressure.
Frequently Asked Questions
A hot water storage cylinder is more of a tank that contains and stores large volumes of heated water for use in homes especially in taps and showers. It can be directly heated with an immersion heater, or indirectly through a boiler. This way, stored water is available when there is a need to provide hot water and despite the high demand for the water.
There are two primary types: Such as; direct and indirect cylinders. A direct cylinder incorporates an immersion heater to heat water and an indirect cylinder uses outside heat such as a boiler or solar panels to heat water. Also, there are two types of cylinders that can be used known as vented cylinders and unvented cylinders.
Vented systems are linked with a cold water storage tank which may be in the loft and relies on gravity to push water.
These cylinders do not have vents and they are directly installed on the mains water supply, providing high pressure without a tank.
The reliance upon it depends on the heating of the home and the pressure of water in the place. If you have a system boiler, an unvented cylinder could be ideal for you as it provides high-pressure hot water and has no space for a cold water storage tank. For example, if you still have an old heating system or low water pressure, it is recommended to use a vented cylinder because it works well with low-pressure systems.
