Electric Heaters (outside of the UK Economy 7 Tariff) remains one of the most expensive forms of heating that there is, especially if you are using Electric Space Heaters to warm the entire room. It is therefore important that you ensure that your property and each room to be heated is as insulated as is possible, and that doors are kept closed as much as possible.
It is also vital that the chosen Electric Heater has an output which matches the amount of heat which the size of the room dictates, larger rooms such as living areas and hallways will need a fairly substantial amount of heat to warm them to a comfortable level. Often this will need more than one electric heater to produce the required heat and it is advisable to try and match the rated output of each heater equally whilst mounting them at either ends of the room in order to maximise the heat output of each Electric Heater.
So for example, if a room size calculator advises that the room will require 4kw worth of heat, then the advice is to purchase two 2kw rated electric heaters, and locate them at either side of the room. Of course, the calculator will probably output a figure which is not an exact kilo-watt, in which case the figure should always be rounded to the next kilowatt of heat, so for example if the calculator deems that a living area or bedoom may need 4.3kw, then you should choose 5kw worth of Electric Heater, this output can be provided by one 2kw heater and one 3kw heater. Since the 3KW heater naturally has more heat output than the 2kw heater, our advice would be to mount the heater with the largest output closest to where people will be sitting or any particularly draughty areas, such as doorways.
Unfortunately if you are one of these people who have just bought one Electric Heater and now expects it to heat a large Lounge then you may be disappointed or be facing high Electricity bills. This is because a room whose size dictates that it needs 4kw – 5kw worth of heat input in order to heat it adequately, and you attempt to heat it with a single heater with a rated heat output of 2kw – 3kw then it will take several hours to get warm, or in the case of a poorly insulated property, it may not actually get to a comfortable temperature at all.
In addition, most Electric Heaters are fitted with built in Thermostats which control the Electricity to the heating element and once the room heats to the desired comfortable temperature, the electric heater will then cycle the Element on/off in short periods order to maintain that temperature, so during the ‘off’ periods the heater consumes no Electricity, thus saving money and reducing the Electricity bill. However if the electric heater is not capable of providing enough heat to match the heat input which the size of room requires, then the heater will never reach the selected temperature and will just run continuously, running up a high electricity bill and in addition the room will probably still not feel warm enough.
Therefore, it is false economy to fit just one heater in a room which may require two or more heaters because it will never feel comfortably warm or actually reach the chosen comfort temperature where the heaters switch off or to a more economical setting. This way, you will literally waste energy running heater(s) which are not poweful enough to heat a room.
The cost of actually running the Electric Heaters depends on two factors. How much you pay for a Kilowatt Hour (KW/H) or ‘unit’ of Electricity, and the actual rating of the Electric Heater(s) which is / are running. To work out the costs, you simply multiply the KW rating of the appliance by the number of hours it is running, and then multiply that figure by the cost of a Kilowatt Hour (kw/h) or ‘unit’ of Electricity and this figure is shown on your Electricity Utility Bill
A Working example of Electric Heater running cost
Electric Heater Rating:- 2kw
Cost of a ‘unit’ (kw/h) of Electricity:- 12p (uk example)
(Total running cost) = KW Rating X number of hours running X Electricity Cost
So in this example 2kw x 1 hour x 12p
So the running cost of a 2kw heater at 12p per unit running continuously would be 24p per hour
To run the same Electric Heater for a period of 5 hours would cost:-
2 (kw) x 5 (hours) x 12 (pence) = £1.20
Of course these are worse case figures as they assume that the Electric Heater would be running continuously for the period specified. As I already mentioned, most Electric Heaters have a built in thermostat which can be used to control the room temperature and once the room has reached the chosen temperature, then the heater will switch off and save Electricity. This is why it is important to chose a heater with a thermostat and to ensure that you have enough heaters to provide at least the same amount as the size of the room requires!.
In this respect, once the room has heated to the selected comfort temperature the electric heater will switch off, and not switch on again until the temperature drops by 1c – 2c. Therefore, you can reasonably deduct around 20% from the above example running figure in order to allow for the electric heater cycling its element, rather than running constantly. How often the heater switches on, depends of course on your own comfort level and how high the heater thermostat is set, it also relies on how well the room is insulated and how much heat the property loses in general.
In properties which have a very poor insulation, or are very cold and draughty then it will probably be much cheaper to avoid Electric Space heating such as convector and fan heaters altogether, and instead look at using personal heaters, such as Halogen Heaters or Quartz Heaters which will work out far more cheaper as they are designed to heat people directly without first heating the actual room first.
Of course, if you intend to use any form of Electric Heating it is paramount that you choose the cheapest energy tariff, as heating using Electricity is extremely expensive, and even 2p or 3p cheaper can save £100’s over a year!. The easiest and quickest way of checking Electricity prices in your area, and comparing the very latest tariffs is to use an Energy Price Comparison Website – and you will often be surprised at the savings which can be returned simply from changing who you buy your Electricity from.
