Cylinders effectively store hot water as part of a central heating system and are ideal partners for air source heat pumps and solar thermal systems.
Cylinders are the ideal solution for domestic hot water requirements. Unless the heat source itself is a combination model that does both heating and instantaneous hot water, a separate cylinder will always be required as part of a central heating system. For example, with air source heat pump installations it is always necessary to have a suitable separate hot water cylinder.
How does a hot water cylinder work?
A cylinder comprises of a highly insulated shell designed to reduce heat loss, various inlets for the water supply to enter and exit as well as one or more coils fitted within the cylinder.
The system water which has been heated up by the heat source travels through the cylinder’s coil(s) where the heat is then transferred to the mains or cistern fed water stored within the cylinder. The hot water exits the cylinder at the top ready to fulfil the household’s hot water demand such as running taps or showers.
What is an unvented cylinder?
An unvented cylinder is one that is directly connected to the cold mains supply. Cold water enters the cylinder from the mains water supply and it is then heated up by the heat source (such as a boiler or heat pump). Unvented cylinders are part of a ‘sealed system’ which means that alongside the cylinder, an expansion vessel is also needed as this holds any excess amount of hot water when it expands inside the cylinder.
What is a vented hot water cylinder?
A vented or open vented cylinder is one that is connected to a cold water storage cistern. With vented cylinders, the cold water is fed from the cistern (often located in the roof) into the cylinder where it is heater up before travelling to the taps when a hot water demand is called for. Open vented system tend to result in lower water pressure at the hot water outlets compared to that of a sealed system using an unvented cylinder.
Grant’s QR cylinders are supplied as unvented cylinders but they can be used as open vented cylinders as well.
Heat pump cylinders
If you are having a new air source heat pump installed (replacing a traditional boiler or fuel source such as gas or oil) and you already have a hot water cylinder, it is more than likely that you will need to have a new cylinder fitted rather than connecting the heat pump to your existing cylinder. This is because not all cylinders are suitable for heat pumps.
When installing an air source heat pump, it is important to check that the cylinder it is being installed with is compatible with heat pumps. Such cylinders have larger internal coils to increase the surface area through which the heat is transferred from the primary system water into the stored cylinder water – this is due to the lower flow temperatures produced by an air source heat pump. All of Grant’s cylinders are compatible with heat pumps.
Twin coil hot water cylinders
For heating systems where there are multiple fuel sources, for example when an oil boiler or heat pump is installed alongside solar thermal panels, there are cylinders which incorporate more than one coil. Twin-coil models allow the heat generated from more than one heat source to be transferred and combined within a single cylinder, providing an efficient answer for properties with a large hot water demand.
The Grant QR Cylinders are a universal range of hot water cylinders which include single coil and twin coil cylinder options. The QR hot water cylinders combine efficient operation with versatility, making them ideally suited to work alongside both traditional heating systems (such as an oil boiler or gas boiler) and renewable central heating systems (such as an air source heat pump or solar thermal system).
Integrated hot water cylinder for heat pumps
A hot water cylinder is normally located in an airing cupboard but for properties where space is limited and a separate cupboard or room is not available, an integrated hot water storage solution is needed. The Grant QR Integrated Cylinder is a cabinet cylinder model which stores a 210ltr hot water cylinder inside a sleek white casing which has a compact footprint. It is therefore ideally designed to fit into kitchens or utility rooms. Furthermore, Grant’s Integrated Cylinder has multiple factory-fitted features which make installation quick and simple.
Please click here to read more about Grant's Hot Water Cylinder range.
