Why should we be energy efficient?
There are three main reasons why energy efficiency make sense: firstly, the world’s natural resources are running out; secondly energy efficiency helps to protect the environment; and thirdly it saves you money. The following pages take a deeper look at a number of energy efficiency aspects including:
- Energy Labeling
- Condensing Boilers
- Heating Controls
- Insulation
- Grants
- Water conservation
- Alternative energy
The IPHE has also put together its Top Tips for saving money, energy and the environment so that you can take steps to minimize energy wastage in your home.
Energy labeling
Energy efficient products are designed to make the most effective use of energy with the minimum of waste. This means that the amount of energy needed to run them is reduced compared to a standard efficiency product. To ensure you can identify energy efficient products you should look out for the EU energy label, the energy saving recommended logo and in the case of boilers, SEDBUK ratings.
The EU energy label rates products from A (the most efficient/least energy used), down to G (the least efficient/most energy used). These are used on items such as refrigerators, light bulbs, washing machines etc. Many pump manufacturers in the UK are also using energy labeling on their products so you can choose an efficient pump for your central heating system.
Boilers are rated according to how much of the fuel they consume is converted to heat, as a percentage. This rating is called SEDBUK - Seasonal Efficiency of Domestic Boilers in the UK. Like the EU energy label, SEDBUK ratings are from A to G, with A-rated boilers being more than 90% efficient.
| Band | SEDBUK range |
| A | 90% and above |
| B | 86% - 90% |
| C | 82% - 86% |
| D | 78% - 82% |
| E | 74% - 78% |
| F | 70% - 74% |
| G | below 70% |
Standard efficiency boilers rate at band D, with their high efficiency counterparts rating at bands A and B.
Condensing boilers
In 2004 the government predicted the UK’s native gas reserves would run dry in 12 years, the UK now imports more gas than it produces. This change from an exporter to an importer of gas has resulted in price rises, which can only get worse as demand for ever decreasing gas supplies increases. On 1st April 2005 it became law to allow the installation of only 'A' or 'B' SEDBUK rated boilers*. These A and B rated boilers use condensing technology to reach high efficiencies. High efficiency condensing boilers convert more than 88% of their fuel into heat, compared to 78% for conventional types.
A condensing boiler with a gas-to-water or primary heat exchanger, of which there may be more than one, has a larger surface area than it would within a non-condensing boiler. This extra surface area allows more heat to be extracted from the combustion process for the same amount of fuel that is consumed in a non-condensing boiler. They require less fuel to apply the same amount of heat to the system, producing less greenhouse emissions.
They are available as regular and combi models, floor standing or wall hung. Care is needed when siting the flue terminal, due to the plume effect. Pluming is the name given to visible flue products leaving an appliance terminal. When gas is burnt one of the products of combustion is H2O (water). In standard efficiency boilers, the flue gases leave the boiler at high enough temperatures for the water vapor to appear invisible. However, in high-efficiency condensing boilers, the flue gas temperatures can be significantly lower and as a result of this the water vapor in the flue gases appears as a mist leaving the terminal.
Manufacturers claim you can save over 30% on your fuel bills by switching to a condensing boiler from a standard efficiency model. In addition to this the installation of heating controls can give you up to an extra 10% saving – that’s about £150 - £180 off the average bill!
Care should be taken to ensure the boiler is installed in a clean system. A new efficient boiler on an old dirty system will not operate as effectively. The system may be corroding and may contain debris, which will inhibit the operation of the boiler. Corrosion reduces the fuel efficiency of the boiler, causes poor circulation to radiators and can lead to pump failure, heat exchanger and noisy operation. It is best practice to flush and chemically treat the system on installation of a new boiler.
*Because of installation requirements, some premises will qualify as an exception. This means a D or C rated standard efficiency boiler can be installed in these cases.
Heating Controls
Controls are very important when it comes to energy efficient heating systems. Controls dictate how the boiler responds to changes in temperature - they tell the boiler what temperature it needs to operate at. An energy efficient system will be sectioned into zones so that different levels of heat can be provided in different rooms. This is very important if you live in a house where only a few rooms are utilized e.g. if a separate dining room is only used on special occasions, it will not require constant heating. Ensuring that the boiler is required to provide heat only for the rooms in constant use can save you money, energy and ensure your own comfort levels are met.
Heating controls can also dictate when the boiler will heat hot water. If you know your household usually showers between 7am and 8.30am, you can set the boiler to fire up and heat the water prior to the time of greatest demand. Many advanced controls use intelligent technology to guess when optimum demand will be placed on the boiler, this ensures the boiler is ready to meet demand but also that it doesn’t waste energy producing hot water when the household is empty.
Insulation
According to the Energy Savings Trust the amount of heat lost annually through roofs and walls is enough to heat three million homes for a year. Approximately 40 - 50 per cent of heat loss in a typical home is through the walls and loft. Therefore, insulating your cavity walls and loft can significantly reduce your utility bills, especially when combined with draught proofing, cistern and pipe insulation and double glazing.
Lag your pipes! Lagging pipes will not only help save energy through stopping excess heat loss, it will also protect against your pipes freezing in extreme weather. In addition to this, buying a lagging jacket for your hot water cylinder will make it far more efficient.
However, consideration should be given to the installation of a pre-insulated cylinder with a ‘high recovery’ coil (heat exchanger). These cylinders are more efficient because the superior insulation will conserve more heat and the high recovery coil will reduce the time taken for the cylinder to reach its desired temperature.
Did you know the cost of cavity wall insulation can be recovered in just over a year and the ongoing savingscan be as much as £100-£120 each year? As well as this there may be grants available to you – it certainly pays to insulate your home. Visit the Energy Savings Trust to see how much you can save.
Grants
There are grants and schemes available to help bring down the cost of making your home more energy efficient. The Energy Savings Trust website has details of grants and schemes available. You can also contact your local Energy Efficiency Advice Centre on 0800 512 012.
Water Conservation
In the UK water shortages are set to become the norm as reservoirs are running low – especially in the South East – where dry winters due to global warming and the demand for new housing have pushed water reserves to their limits. Luckily there are many simple measures we can take in the home to save water.
Taps are very important when it comes to water conservation. Make sure you turn taps off properly. Dripping taps waste up to 30 litres a day – not only wasting a valuable resource but also your money too. Taps that drip even when closed are also a sure sign your plumbing system is in need of maintenance. Regular maintenance will not only ensure your system is working to the best of its abilities, it also reduces the risk of major problems occurring.
The type of taps you install can save water. Those which use a spray pattern can use up to 80% less water than a traditional tap. Also, using a water saving flush or dual flush system on your WC can save the amount of water you use and also greatly reduce your water bills. For those with WCs installed before 1991 devices such as the Hippo can be installed, which reduce the flush volume by around 2.5 litres. For WCs installed from 1992 - 2001 the Save-a-Flush can be used to reduce the amount of water used when flushing by one litre. Homeowners should make sure the water level inside the cistern is set at the correct level and is well clear of the overflow pipe, if the level is too high it will overflow, wasting water and your money. Other ways to save water include ensuring you use the washing machine and dishwasher only when fully loaded, having a shower instead of a bath, washing your car with buckets of water opposed to using a hose and having a water meter installed.
Your local water company should be able to offer help and advice on water conservation, some may even offer water saving devices for free. For more ideas on how to save energy please visit www.est.org.uk or call your local Energy Efficiency Advice Centre on 0800 512 012. You can also visit the IPHE’s Top Tips for saving money, energy and the environment.
Alternative energy
Electricity is a key contributing factor to global warming as a third of all carbon emissions from the UK come from the burning of fossil fuels to generate electricity. Countries and manufacturers across the world are investing millions of pounds into research and development of energy efficient products that will do little damage to the environment. Some of these products are widely available, others are just emerging as real options for the future. Here is the IPHE’s brief guide to the main forms of alternative energy.
Solar
Solar panels have been used in mainland Europe for decades, but the rising trend in the use of solar power is only a recent development in the UK. Advances in technology mean they will utilize many different kinds of sunlight, so that even on a cloudy day they will produce energy. Solar panels are normally used to heat water and can supply up to 80% of the energy needed to heat water in your home, giving you a significant reduction on your heating bill.
Solar panels collect energy from the sun, which is then transferred to a generator. This generator converts the solar power into usable energy, which is then used to heat the hot water cylinder. In many applications solar energy is used to pre-heat water, thus reducing the amount of energy used by the boiler to bring the pre-heated water up to the desired temperature.
The price for installing solar panels is coming down, and the range of manufacturers and products available is expanding. Although the payback time can be long compared with other energy efficient products, they can be fitted to an existing or new-build properly, and can be used in domestic, commercial or industrial applications. As you are collecting and using the energy direct, the usual wastage that occurs between the place of energy production and transference to your home does not apply. Some manufacturers claim their solar panels will save up to 700kgs of carbon-dioxide a year, which helps to combat global warming.
Ground Source Heat Pumps (GSHP)
Heat pumps are very versatile and can use earth, air and water to conduct heat, however, in the UK the most effective heat pumps use the earth. They are environmentally friendly, extremely efficient and can be used to both heat and cool your house. In essence Ground Source Heat Pumps use the refrigeration cycle to upgrade a source of heat, at a low temperature, to a higher one. A pipe circuit is laid beneath the earth’s surface and through this an anti-freeze mixture is pumped. This then passes back through an evaporator exchanger in the heat pump to the refrigerant circuit. In turn this is compressed and then condensed and passed through another exchanger into the heating system pipework at a working temperature of around 50°C or even higher if additional circuitry is included in the heat pump.
Simplified this means that during colder weather, the fluid collects low grade heat from the earth and carries it through the system to be converted to high grade heat for use within the building. During hotter weather the system can be reversed to cool the building by taking high grade heat from the building, using the energy to heat water etc and placing the left over low grade heat back into ground. This process creates free hot water in the summer and delivers substantial hot water savings in the winter.
Heat pumps have a service life of up to 20 years and can be installed in a structure of any size providing there is room to install the underground piping – i.e. the property will need an area of land such as a garden in which to place the underground pipework. It is a system better suited to new-build housing – if you have a well established or landscaped garden you may not wish to have it dug up to lay underground pipework! The payback time can be as little as five years as they produce up to 75% energy for free.
Combined Heat and Power (CHP)
Combined Heat and Power (CHP) is a fuel-efficient energy technology that, unlike conventional forms of power generation, puts to use the by-product heat that is normally wasted to the environment. The principle is that a gas or oil fuelled engine produces energy much in the way of a traditional boiler. A secondary heat exchanger then absorbs the exhaust heat (which is normally wasted) from the existing engine/boiler and uses that to drive an electrical generator. Therefore, for every kilowatt of energy used to drive the generator, two kilowatts of usable heat energy is produced.
The main generator/boiler would typically be providing the space heating and hot water for a home, industry or community and the recovered energy would be used to supply electricity for lighting, cookers, refrigerators and other kitchen machines. Excess energy produced can be sold back to energy providers.
CHP can reduce the carbon emissions, from about 10% to more than 30%, depending on the amount emitted by the primary generator. Although currently being used in larger applications, Mirco Combined Heat and Power units are available for domestic use. It is expected that in the years to come Combined Heat and Power will be the main energy source for may households and business in the UK.
Fuel Cells – the Hydrogen economy
Governments and companies around the world are looking into the possibility of a hydrogen economy, whereby hydrogen powers anything from cars, to laptops to central heating systems. This will be done through the use of fuel cells, which will generate electricity from an electrochemical reaction in which oxygen (air) and a fuel (e.g. hydrogen) combine to form water. There are several different types of fuel cell but they are all based around a central design. Fuel cells are an extremely efficient means of producing power - the electricity produced can be used to power all sorts of devices and the by-product heat can also be used in heating systems to warm a home or help heat water.
The Institution of Energy and Technology (formerly the Institute of Electrical Engineers) explains, ‘A fuel cell works much like a battery. In both batteries and fuel cells two electrodes, an anode and a cathode, are separated by an electrolyte. Whereas a storage battery contains all the substances in the electrochemical oxidation-reduction reactions involved and has, therefore, a limited capacity, a fuel cell is supplied with its reactants externally and operates continuously as long as it is supplied with fuel’. – ‘Fuel Cells’ published by the Institution of Energy and Technology.
Fuel cells can be used in a number of applications from powering cars and buses, to producing heat for buildings and they have been used extensively in space where they create power and clean drinking water (water is a by-product of the electrochemical reaction of oxygen and hydrogen). It is believed fuel cells will be used in far smaller applications in the future as technology advances.
Useful links
The Energy Savings Trust www.est.org.uk - useful advice for home owners.
The Carbon Trust www.thecarbontrust.co.uk/carbontrust - advice for businesses on cutting carbon emissions
NetRegs www.netregs.gov.uk - advice on environmental legislation that affects businesses
SEDBUK www.sedbuk.com - information on SEDBUK ratings for installers and consumers
www.direct.gov.uk - www.direct.gov.uk/HomeAndCommunity/EnvironmentalMatters/fs/en - information on a whole range of water conservation and environmental matters.