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The following short articles cover a variety of ways to save energy:
    10 free ways to save  •  Draught-proofing  •  Insulation methods  •  Heating controls
Devices on standby are considered in more detail in:
   Devices on standby  •  Standby energy consumption

Related pages present advice on Monitoring Energy Usage and Smart Meters, and miscellaneous Energy-Related Topics.
The content of all the articles is summarised on the Energy Advice page.

10 Free Ways to Save Energy

Money falling from house
  1. Turning your thermostat down by just 1 degree Celsius could cut your heating bills by up to 10 per cent.
  2. Is your water too hot? If you have a separate hot water tank, and this is large enough, the cylinder thermostat should be set so that you do not need to add cold water when using the hot tap.
  3. Close your curtains at dusk to stop heat escaping through the windows.
  4. Always turn off the lights when you leave a room.
  5. Don't leave appliances and gadgets on standby or recharging batteries unnecessarily.
  6. If you're not filling up the washing machine, tumble dryer or dishwasher, use the half-load or economy programme.
  7. Only boil as much water as you need (but remember to cover the elements if you're using an electric kettle).
  8. A dripping hot water tap wastes energy and in one week can waste enough hot water to fill half a bath, so fix leaking taps and make sure they're fully turned off.
  9. When cooking choose the right pan size for the food and the cooker, cut food into smaller pieces and put lids on pans as the food will then cook a lot quicker.
  10. The sun is the most readily available source of heat there is – and the cheapest! So make the most of it by opening internal doors of any rooms which get more sun than others and let the warm air travel through your home. Avoid using tumble driers and radiators to dry your clothes when possible; on nice sunny days clothes can be dried outside.



Windy Day

What is draught-proofing?

Draught-proofing is the process of filling in unnecessary gaps in the fabric of a building to reduce heat loss and discomfort due to draughts. You can draught-proof windows, doors, letter boxes and& keyholes. You can also fill in gaps in walls due to plumbing, and gaps in floorboards or skirting boards. The materials used for draught-proofing include foams, brushes, sealants, and thin sections of rubber, plastic or metal.

What are the benefits of draught-proofing?

Draught-proofing is a cheap and cost-effective way to reduce your heating bills and make your home feel warmer. Draught-proofing is also very effective at eliminating cold draughts that can make you feel uncomfortable and cause you to turn up the heating. You can easily check where in your home needs draught-proofing. Hold the palm of your hand up near windows or doors. If you can feel any cold air coming in, then it's worth draught-proofing that area; it will stop the cold air getting in and the warm air getting out.

How much does draught-proofing cost?

Draught-proofing costs very little if you do it yourself, but contractors or a local handyman should not be expensive. If you decide to fit draught-proofing yourself, you can buy the materials in most DIY stores; make sure they conform to standard BS7386.

What else can I do to stop draughts?

Try hanging thick curtains in front of doors and windows. They will stop heat escaping and prevent cold air from entering, so your home will feel warmer and more comfortable. Shut the curtains at dusk to keep the heat in. Curtains with a thermal lining will be even more effective, and placing material "snakes" at the bottom of doors will also help stop draughts. Don't forget the letter box and keyholes.

BUT . . .

A word of warning – don't go mad! Your home needs ventilation to be safe, to stop it becoming stale and stuffy, and to eliminate the possibility of condensation and mould growth. Ventilation is essential if you have solid fuel fires, gas fires or a boiler with an open flue. So check air bricks for blockages, do NOT block them up. Ventilation is also essential in kitchens and bathrooms, so if there are not other means such as an extractor fan, don't draught-proof there either.

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Insulation Methods

Penguin advertising Cocoon

The village energy surveys conducted by the Initiative revealed that most homes had some loft insulation but nearly all could benefit from a top-up. Cavity walls are often not filled with insulation. There was also little solid wall insulation, which whilst difficult is possible in many cases. All this adds to fuel bills and impacts on the environment as more fossil fuel is used to keep warm. Simple additional insulation measures can be effective and inexpensive.

Roof – 270 mm (10.5 inches) of insulation is recommended for lofts. Mineral wool, fibreglass, sheep's wool and recycled paper products all work well. Insulation can be installed by a contractor or you can do it yourself. If doing it yourself:

  • Wear a face mask, goggles and protective clothing.
  • Leave sufficient gaps around the eaves to avoid condensation.
  • Do not insulate under water tanks, to keep them from freezing.
  • Ensure all pipe work is insulated.
  • Insulate the loft hatch.

Walls – Wall insulation can reduce heat loss through the walls by two-thirds and make your home more comfortable. Cavity walls can be safely filled with insulating fibre, beads or foam (foam is not suitable where walls are exposed to driving rain). For solid walls internal insulation can be highly effective. Typically an insulated board is fixed to the wall. This means rooms have to be redecorated and may lose architectural detail. The work can be done by competent DIYers and may be done on a room by room basis at the same time the home is redecorated. External insulation is more difficult, it usually needs planning permission and should only be carried out by specialist companies.

See our domestic grants page for information about the Green Deal, which can help with insulation installation.


Heating Controls That Save Energy

Energy efficiency in the home is not just about improving levels of insulation. Modern, easy to understand controls, designed to ensure that the boiler is only working when actually needed, are every bit as important.

A good heating control package will normally include the following:

  • an electronic timer or programmer,
  • a room thermostat,
  • thermostatic radiator control valves (TRVs), and
  • separate thermostatic control for the hot water system.

Additional controls that may be worth considering to get the very best from a central heating system include:

  • intelligent heating controls,
  • a programmable thermostat,
  • a weather compensator,
  • a boiler energy manager,
  • full zone control, and
  • remote control.

Basic controls

The timer or programmer

Image of heating programmerThe electronic timer or programmer decides when the boiler is able to run. It is not true that boilers work best when they are running continuously, or that energy is saved by leaving the heating on all day even if the home is unoccupied. Whenever the boiler is firing it is using energy, and whenever the home is being heated to a temperature above that outside, it will be losing heat to the outside world. In spring and autumn there is no need to keep the heating on all day; a reasonably well-insulated home can be left to cool down slowly with the heating timed to come on perhaps an hour or so before people return home from work.

A seven day timer is also strongly recommended, so that it is possible to set a different heating pattern for weekdays and weekends. Some programmers incorporate built-in thermostats and temperature sensors. These need to be sited in a living room rather than by the boiler, but can often represent a good investment.

The room thermostat

This is best located in a living room rather than the hallway, as is commonly done, because the hall temperature can be affected by the front door being used. The thermostat measures the home's temperature, and if it is at or above the set level (19–20°C/66–68°F is usually adequate) it stops the boiler and the heating pump. Wireless thermostats now available do not need wires to be installed, and can be moved to different rooms depending on where you want to regulate the temperature.

Image of radiator thermostat

Thermostatic radiator control valves (TRVs)

These switch individual radiators on or off, depending on how warm the room they are located in is. They usually have a fat valve at one end, marked with a * and numbers from 1 to 5. The * setting is to protect against frost; it will typically leave the radiator switched off unless the temperature falls below about 6°C.For a normal living room, the setting of 3 or 4 is likely to be about right; for a bedroom a cooler temperature will normally suffice. Turning the dial up when the radiator is already on will not increase the roomtemperature! It is not a good idea to have a TRV on the radiator in the sameroom as the main thermostat, because if it turns the radiator off at a lowertemperature it can mislead the main thermostat into thinking that the rest ofthe house is cooler than it really is.

Thermostatic controls on the hot water system

Image of hot water tank thermostat in situ

This section only applies to systems with a separate hot water tank, not combi boilers. First, it is most important that the hot water can be controlled by the programmer separately from the central heating. Some older systems only allow the heating to run when the hot water is on; this can be quite wasteful of fuel. Second, there should be a thermostat on the hot water tank – this is usually strapped to the outside, fairly near the bottom. This controls the water temperature – it should not normally need to be set higher than 60°C, and beyond this there is a danger of scalding.

The room thermostat and the hot water thermostat should be wired up to the boiler in what is known as an "interlock".This means that if both the house and hot water are at temperature, the boiler will be switched off. If this does not happen, then when the water temperature inside the boiler itself falls, an internal thermostat will cause the boiler to fire to heat up this water – a process known as "dry cycling". All the energy used in this cycle is wasted, as it does not serve any useful purpose.

More advanced controls

Intelligent heating controllers

Intelligent heating controllers, such as the "Dataterm", combine several of the functions above and can also learn how long it takes for a house to heat up in different weather conditions. These also often allow for different temperatures to be set between day and night. They give the very best control over central heating, although they cost somewhat more than normal controls.

Programmable thermostats

Programmable thermostats allow the target temperature of a heating circuit to be varied over the day, for example with a warmer temperature in the early morning and in the evening, a cooler temperature during the day, and a low setting at night. Having a separate setting at night avoids the common practice of simply turning the heating off even when it is very cold outside. These thermostats provide for different time periods and temperature settings during weekdays, and during weekends. More complex versions allow different settings for every day of the week.

Weather compensators

These measure the temperature, either internally or externally, and delay switching on the central heating on milder days. Simple ones are quite inexpensive and replace a normal room thermostat; they are well worth considering, although the programmer will appear to need to be left on for longer periods when they are first installed.

Boiler energy managers

There are many kinds of boiler energy managers available, ranging from simple devices that delay a boiler firing (and work rather like just turning down the thermostat!) to complicated ones optimised for a particular model of boiler. The general advice is that simple strap-on devices are probably not a good investment, but that if a boiler manufacturer recommends one for use with a specific model of boiler, then they are worth fitting at the time that the boiler is installed.

Full zone control

Most homes have a single heating zone – the only single-room controls are by TRVs. However the need for heating in the main living rooms can be quite different from that in bedrooms, with the latter requiring lower temperatures for longer hours. At the time a new central heating system is installed, it is possible to fit a full zone control that has different pipe loops and separate thermostats for two (or more) areas. This can save significant amounts of fuel in larger houses.

Remote control

Some heating control systems can be controlled remotely over the Internet, so for example a single occupier can turn on the heating when they are about to return home.

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Devices on Standby

Sleeping Photocopier

Many electronic devices are left powered up when they are not being used. An average household might spend £40 or more per year just keeping devices in this state.

Computers, set-top boxes, internet routers and other devices are often left running to avoid the inconvenience of starting them up when they are required.

Some devices have a standby state in which the device can be restarted conveniently. For example a TV typically goes into a standby mode when switched off by its remote controller.

It may not be obvious that the device is in a standby state. For example, some computer printers are actually put into a standby mode when they are switched "off", and take nearly as much energy when switched "off" as they did when switched on but not being used. In this state such a printer typically consumes about 10 watts, costing about £10 per year.

The AC adapters and chargers which are typically built into mains plugs or small black boxes in the mains lead also take noticeable power when the mains is connected, even when they are in the no-load state and not connected to the device they are designed to support. The only reliable way to ensure a device is not taking electricity is to switch it off at the mains socket.

Other devices often left in a standby mode include DVD, CD and VHS players, amplifiers, video recorders, computer monitors and speakers, microwave ovens, washing machines, tumble driers and dishwashers.

It is estimated that a power station generating 500 megawatts or more needs to be run continuously to power all the devices left on standby in the UK.

Devices on standby will be generating heat and thus will slightly reduce the need for other kinds of heating. However electricity is a very expensive form of heating, and the heat is not needed for much of the year.

Those who enjoy the Dragons Den programs on TV may remember the most successful presentation to them was of a device to switch off all the devices which otherwise would be on standby. All the dragons wished to invest. Although this deal fell through the device is now available as Standby Saver (www.standby-saver.com) at £21.95. There are also alternative products such as Bye Bye Standby (www.byebyestandby.co.uk).

The Energy Initiative has not tested either product. The following article was researched by a member of the Initiative.


Standby Energy Consumption

On/Standby Button

A member started this exercise to learn more about how much electricity is wasted by leaving devicespowered up and on standby. He was thinking in terms of two situations:

  • devices that do not really need to beleft in standby (for example a TV that comes on almost immediately, the only advantagebeing that you have to go to the TV instead of using the remote control), and
  • devices wherethere is some advantage in leaving them on, for example a computer that takes a while to reboot, or a hard-disk video recorder which also serves as a digital TV set-top box, and which often takes quite a long time to update the on-screen programme guide if not left on.
Maplin Monitor Socket

Although not all brochures specify the power used on standby, it was already obvious that there are very big differences. In addition, some devices do not even have on-off switches. However, in the course of doing the measurements another serious waste of energy was discovered, in the form of the electronics built into mains plugs or small boxes to convert mains AC to a low-voltage supply for the device. These are often called mains adapters, but below are referred to as external power-supply bricks.

  • Readings were taken with a Maplin 'monitoring socket' that you plug things into. It goes down to 1 watt, but may not be very accurate at those levels. However, it easily distinguishes a 1 watt device from a 4 watt or 10 watt one.
  • A device using 1 watt continuously on standby consumes about 8.8 kilowatt-hours per year if it's left on all the time. At 12p per kilowatt-hour this costs about £1 per year more than turning it off. (Think of it as each watt you leave on costing £1 per year.)
  • Before the work started a total house monitor showed minimum consumption of the entire house as low as 50 watts, on the rare occasions when heating, fridge, etc. were all off. Many devices were normally switched off. But as will become evident, a large fraction (around half) even of this remaining 50 watts could be eliminated.
  • We see in the table a variety of situations. Some devices use a lot of power in standby mode, well above the European target of less than 2 watts.
  • Other devices consume very little power, and leaving them in standby is not serious.
  • Not fitting a mains switch, especially when the device consumes several watts minimum, should not be allowed – there is no good reason to leave most of these things on.
  • Two items (tape cassette deck and halogen reading lamp) consume substantial power even when switched off, despite not having external power-supply bricks. A switch in the mains lead fixes this.

Although some of the numbers were surprisingly high, the standby situation motivates trying to switch a few more items off, and to fit switches in the mains leads of devices with no switches.

TVs are often shown as examples of devices left on standby. The table below illustrates that they are far from being the worst offenders, and many recent flat-screen TVs consume only about 0.2–0.3 watts in standby mode.

What had not been appreciated was just how many external power-supply bricks there were, and how much they consume. You may think adevice is switched off, but it is actually consuming a few watts all the time unless it is switched off at the mains socket, which is often located out of easy reach. Looking globally, the UK is one of the few countries which even has switches on its mains sockets – most of the world does not, so switching external power-supply bricks off at the socket is not an option. In all the talk about how much energy is wasted by standby no one seems to mention this.

The devices measured

Item Type and model Power Comments
Television Panasonic TX-21AD2/M 1W (standby) 21-inch CRT. Normally switched off.
Video cassette recorder Panasonic NV-HD630 6W (standby) Standby needed if set for timed recording. Normally switched off.
Hard-disk video recorder Humax PVR-9200T 9W (standby) Standby needed if set for timed recording; also greatly reduces delay in loading on-screen programme guide. Normally switched off.
DVD player Panasonic DVD-S49 1W (standby) No on-off switch fitted; one was added. Normally switched off.
CD player Meridian 206 16W (standby) (18W when on!) Slightly better sound quality claimed for first 1–2 hours if left in standby. (Old model, high quality.) Now normally switched off!
Tape cassette deck Yamaha KX-580 6W (off!) No warning that it consumes power when switched off! (No external power-supply brick is visible.)
Desktop computer + LCD screen + ... Apple PowerMac G4 +
17-inch flat-screen display
5W (sleep) Entire system consumes 40W with computer in sleep mode (including printer, scanner, modem/router, etc.). Some little-used items were disconnected.
Laser printer (mono) HP LaserJet 1200 8W (idle) Now normally switched off.
Inkjet printer (colour) Epson Stylus Photo 870 11W (idle) Normally switched off.
Scanner Epson V350 Photo 3W (off), 6W (idle) Consumption when off due to external power-supply brick. No on-off switch fitted; one was added. Normally switched off.
Laptop computer Apple PowerBook G4 5W (sleep) Measured when plugged in and fully charged.
Midi keyboard Yamaha PortaSound PSS-680 2W (off) Consumption when off due to external power-supply brick.
DAB radio Pure Evoke-2 4W (off) Consumption when off due to external power-supply brick. Now switched off at the socket.
Halogen reading lamp John Lewis 4W (off) Consumption when off due to power supply within base. Switch now added in mains lead.

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