Got a question about gas, electricity or energy efficiency? The Energy Doctor can help!
Email your questions to editor@uswitch.com and we'll answer the best ones and post them here.
Q. Is it true it costs more to switch lights off and then on again, than it does just to leave them switched on?
A. It is a myth that it costs more to switch your lights on and off than to leave them running.
Old-fashioned incandescent bulbs (the kind with a filament in them) do not draw any more power than normal when they are first turned on. If a bulb says 60W on it, it will draw 60W of power from the instant it is switched on, so it will always be cheaper to turn them off than to leave them running.
With low energy (energy saving) bulbs, it is again cheaper to switch lights off when you leave a room than to leave them switched on. While low energy bulbs do draw more power in the first few minutes of being switched on than they do when they are running normally, the energy used by them starting up is only the equivalent of leaving them running for a few minutes. Unless you are switching your lights on and off every few minutes, it will be cheaper to turn them off than leave them running.
Q. Is it cheaper to leave the central heating on at a low temperature rather than switch it on and off as needed?
A. It is a common misconception that it is cheaper to leave your heating on all the time.
Boilers use more power initially to heat radiators from cold, however the cost of doing this is greatly exceeded by the cost of keeping the boiler running all of the time, even if you set the temperature of the central heating down low.
You should set your heating to come on shortly before you are going to need it (for example before you get up in the morning or before you come in from work) and go off again at a time when you leave the house. Some central heating programmers will let you enter different programmes for weekdays and the weekend when you are likely to need your heating at different times.
If someone is in the house all day, then the central heating may need to stay on, but you can minimize the cost by making sure that radiators are turned down in rooms which are not in use (although not in the room where the central heating thermostat is located, which would interfere with the central heating regulation), and try to find how low you can comfortably set your thermostat. Between 18 and 21 degrees Celsius normally provides a very comfortable temperature, but you will need to play around to see what is best for your house.
Q. Are there energy saving light bulbs which don't take ages to reach their full brightness?
A. Some energy saving bulbs can take a little longer than normal bulbs to reach full brightness, but this is a result of the technology they use, which is also what makes them so much more efficient that traditional incandescent bulbs.
Many modern energy saving bulbs take little more than a few seconds to warm up to full brightness. You should look for the Energy Saving Recommended label when choosing your energy saving bulbs, as these have to pass certain criteria on maximum warm-up time, and you can also get energy saving bulbs which are designed to be fast-start bulbs, meaning that they do not have a warm-up period. Look for bulbs labelled 'fast-start' or 'quick-start' when you are buying new ones.
Q. How do I know if my walls already have cavity insulation?
A. If you want to find out whether or not your home has cavity wall insulation, you can request a free survey from any cavity wall insulation installer registered with CIGA (the Cavity Insulation Guarantee Agency). They will be able to tell you whether or not you already have insulation in place. Go to the CIGA website or ring them on 01525 853300 for a list of registered installers in your area.
Q. What are the minimum insulation standards that landlords of residential property are legally required to fulfil?
A. Currently, landlords are not legally required to install insulation in residential properties.
However, landlords can claim a tax allowance, known as the Landlords Energy Saving Allowance (LESA); this allows them to claim on their tax return against the cost of buying and installing energy saving items, including draught proofing, loft insulation, floor insulation, cavity or solid wall insulation, and insulation for hot water systems. The tax relief is for up to £1,500 each tax year per property. To find out more about LESA, contact your accountant or tax advisor, visit Directgov or call the Energy Saving Trust on 0800 512 012.
Q. Will I save money by turning radiators off in individual rooms?
A. You will almost certainly be able to save money by turning your radiators off in individual rooms when those rooms are not in use. It is a waste of money and energy to be heating a space when it is not needed. Close the doors to any unheated rooms where you have turned off the radiators to help stop the warm air from the heated rooms or spaces escaping into the colder ones.
The one room where you should not turn off (or turn down) a radiator would be in the room where your house thermostat is fitted, if you have gas central heating, because it can interfere with the temperature regulation of the central heating. However, turning radiators off in other, unused rooms if you have gas central heating will not interfere with the system, and will almost certainly save you money, as your boiler will have to do less work to heat fewer rooms.
Q. Is it better to just use the gas fire in my living room to keep my house warm or to heat up the whole house with the gas central heating?
A. Depending on the age of your central heating boiler, gas central heating is usually more efficient at providing heating compared with gas fire, as it is able to produce more heat per unit of gas used - a lot of the heat produced by living flame gas fires may escape up the chimney. An older central heating boiler will not be as efficient as a modern, condensing (energy efficient) boiler, but will still be more efficient at producing heat than a living flame gas fire.
Which works out more cheaply for you will probably depend on how many rooms you have or want to heat, and whether you can control the individual radiators in the different parts of your house.
If you cannot turn off or turn down the radiators in the other rooms in your house, you will be better off using your gas fire, as by using the central heating you will be wasting money heating unused rooms. However, if you can control your radiators individually, then you will be better off using the central heating system and turning down or turning off the radiators in any unused rooms. If you are currently unable to control your radiators individually, thermostatic radiator valves (TRVs) can be installed on most gas central heating radiators by a plumber or experienced DIY person, and you may even be eligible for a grant towards the cost of installing them. Please call the Energy Saving Trust on 0800 512 012 for more information on this, and on what grants are available. Grants may also be available towards upgrading your central heating boiler to a modern, energy efficient model.
Q. What's the most effective way of heating my all-glass conservatory?
A. The first thing to consider is whether your conservatory has double- or triple-glazed glass, or whether it is made of single-glazed panes. If it is single-glazed, it may be difficult to keep it heated to a comfortable level in cold weather. In this case, if you wish to use it in cold weather, you could use heaters such as halogen heaters or fan heaters, which can be used to direct heat at the people sitting in the conservatory rather than heating all the air in the conservatory. Not all halogen heaters are suitable for indoor use, so check when you buy to make sure that it is suitable for your purpose.
If you have double or triple glazing, then the conservatory will be better at holding in heat. In this case you can consider fitting a radiator of the type you have in the rest of your house. There is not a lot to choose between different electric radiators (e.g. night storage, convection, oil-filled), as they tend to have very similar efficiencies, so if you are happy with the radiators you have in the rest of your house I would recommend fitting the same kind.
Finally, building regulations may require that any heat source in a conservatory is controlled independently of the heating in the rest of the house. This means that anything you install must have a thermostat built into it, and/or allow you to switch it off at its source (e.g. a plug on the wall). It is best to check with the planning department of your local planning authority for further advice on this matter.