what types are available?
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Your central heating system plays an important role in your home – providing you with the heat and hot water that makes life so much more comfortable. But what systems are available and how do they work?
What types of central heating systems are available?
Central heating is a way of delivering heat to your home from, as the name suggests, a central source. Central heating systems generally belong to one of the following types:
How does a humid central heating system work?
With a “wet system”
hot water circulates through a pipe system
that connect to radiators throughout a house. At the center of the system, a boiler burns a fuel – or sometimes there is a “heat exchanger” and this heats the water that feeds the pipe network. “Wet systems” are the most popular form of heating system in the UK.
Radiators, despite their name, do not only give off radiant heat, in fact they deliver most of their heat by convection; the air heated by the radiator naturally rises and the cool air descends relative to it, as a result the heated air circulates and the “space” in a room is warmed.
The piping can also be connected to a hot water tank (tank), which will provide a hot water supply for the bath and toilet.
What type of fuel is used in a boiler?
The most common fuel used in boilers is
natural gas, followed by
heating oil, and occasionally liquefied petroleum gas (
LPG). Although rare, some boilers burn coal (usually in the form of charcoal pellets) or biomass (usually in the form of wood chips).
Electric central heating boilers are also available.
New gas (and oil) boilers need to be around 90% efficiency or better (an A or B energy efficiency rating) and typically use condensing technology to achieve this. If your boiler is over fifteen years old, you may want to consider replacing it with a new energy efficient one.
What is the difference between a combi boiler and a conventional boiler?
In addition to meeting your heating needs,
combi boilers provide instant hot water. They have the advantage of freeing up space in a house, because there is no need for a hot water tank (tank) as is the case with a conventional boiler.
In most cases, heating water instantly is more energy efficient than “storage” hot water systems. However, the hot water flow is slower than if it came from a cylinder, so a bath will take longer to operate. Certain combination boilers can in any case also heat water in a storage tank.
Modern boilers generally no longer have tanks in the attic to “pressurize” the system by gravity. Instead, they are sealed systems and typically only require manual top-up from the mains water supply when internal pressure has dropped (usually due to tiny leaks). This is a simple operation that takes a few seconds, and consists of opening a valve on a pipe below the boiler.
My house is heated by a district heating system, how does it work?
In some areas, notably Nottingham, a centralized district heating source will provide hot water through a series of underground pipes to a number of homes simultaneously, eliminating the need for a home boiler. This domestic hot water then circulates around the pipes inside the house to provide heating and hot water. The appeal of this type of system is its energy efficiency and low carbon footprint, and for the consumer that means lower energy bills.
I’ve heard that ground source heat pumps are environmentally friendly, but will they lower my energy bills?
A ground source heat pump works on the same principle as refrigerators and air conditioning systems – making one place cooler while making another warmer – or vice versa. If you consider how hot the back of a refrigerator gets while the inside gets cold, you start to get a feel for how this system works.
Geothermal heat pumps, powered by electricity, operate by
make the earth outside a house cooler, by circulating a refrigerant in pipelines buried in a trench or a borehole, while
supply heat to the heat exchanger inside
. This heat is transferred to the water that circulates in the pipes inside a house to heat the radiators and provide hot water.
Ground source heat pumps typically reach temperatures of around 50 ° C, which is significantly lower than that of a boiler, which can reach as high as 90 ° C (although it is recommended to set the temperature lower). So, you’ll have to run a heat pump longer to get the same level of comfort, and it tends to work better with underfloor heating than with radiators. Although much more expensive to install, they can be as inexpensive to operate as gas central heating. they are a
good option to consider if you live off the gas network.
How does a hot air system work?
Hot air systems were sometimes installed in the 1960s and 1970s in the UK, but continue to be popular in North America.
The air is heated by a boiler, usually powered by natural gas, and routed through ducts to rooms around the house.
. Hot air enters the room through a floor or wall vent.
In commercial buildings, variants of hot air systems are still widely used, although they usually also serve as a cooling system (air conditioning).
In most homes, hot air systems have been replaced by “wet” systems, which are generally more comfortable and efficient.
How does a storage heating system work?
The principle of a storage heater is that it contains bricks capable of storing large amounts of heat. These are heated at night with off-peak electricity in Economy 7 and, at Economy 10 fares, for two shorter periods during the day. This heat is then gradually released the next day.
Storage heating systems, although mostly made up of individual storage heaters, usually rely on a separate wiring system inside the house for cheaper electricity in off-peak hours (Economy 7 or Economy 10), and can therefore still to some extent be described as a “centralized” system. The same wiring will generally also be used to heat a hot water tank (tank).
A storage heater normally has at least two controls, one to control the amount of electricity used, which will determine the amount of heat generated for storage, and another to control the amount of heat released. This means that if you are outside during the day, you can delay the heat release until you return in the evening. More advanced storage heaters also have thermostatic controls.
Unlike the old storage heaters, which took up a lot of space, the modern ones use bricks with a much larger heat storage capacity and are much more streamlined.
In some cases, storage heaters can also function as direct electric heaters, providing heat directly from the electricity without going through the storage stage. Typically, they will use peak tariff electricity for this. Often homes that depend on storage heaters will also have separate electric heating systems to supplement the heating needs; again, peak tariff electricity will be used to supplement in this manner.
Electric central heating vs gas central heating
Which of the two to choose? We take a quick look at the pros and cons.
Electric central heating
The main advantage of installing electric central heating is that it is available for homes not connected to the gas network. In addition, electric night storage heaters are easier to install than gas central heaters when it comes to installing central heating mainly because they require fewer rooms.
In terms of downsides, it should be noted that electric central heating is often more expensive because unit prices for electricity are up to four times more expensive than gas prices. On top of that, electric central heating storage heaters do not provide instant control. This means that you will have to plan your heating needs in advance, as turning the heater on at night means it will heat up for the next morning.
Gas central heating
The main advantage of gas central heating is that it is cheaper, per unit, than electricity. In addition, gas boilers are becoming more and more efficient. Replacing an old boiler with a new energy efficient boiler is quite straightforward in terms of the installation process. You can consider buying a new boiler here.
However, gas central heating is not without its problems. Gas prices continue to rise, and although they remain below the unity of electricity costs, they are far from cheap. Another problem that some houses face is that they are not connected to the gas network. Logging in can be time consuming and expensive. Gas central heating boilers should also be serviced regularly to ensure they are in good working order.