Storage Heaters

Storage heaters differ from many forms of Electric Space Heating as they use lower priced ‘off peak’ electricity in order to store the heat for later convective use. Storage heaters are still popular in the UK, largely being the first choice for cheaper Electric Heating for remote properties which are off the Natural Gas grid system, and where installing oil heating would be impractical or expensive. Storage heaters also remain a popular choice for landlords who rent out properties to tenants, this is usually because unlike Gas or Oil boilers storage heaters require little, if any maintenance, no annual servicing and are pretty much a ‘fit and forget option’

Storage Heaters have been around since the 1970’s and 1980’s when they first found popularity in high rise flats, where Gas installations would have been costly, however like any heating system which has remained faithful to a 25 – 30 year old design, storage heaters do have a very mixed opinion and they also have negatives as well as positives. However one thing is certain is that Storage heaters will be around for some time to come, and will remain pretty much the most viable option in certain properties and those with landlords who refuse to fit any form of central heating.

Storage Heaters are designed to use off peak electricity for heating, in the UK this is largely refered to as Economy 7 or Economy 10, many years ago this was also refered to a ‘white meter’ and this term is often still used in Scottish Properties. This is because when they were first introduced, Storage heaters used two meters, one black meter for daytime use, and a white meter which recorded overnight ‘off peak’ consumption, hence the ‘white meter’ reference. However most properties now have a single meter which records both peak and off peak tariffs.

Storage Heaters consume a fair amount of Electricity, with small models consuming 800w to 1.7kw and larger models consuming 2.55kw and 3.4kw. Small storage heaters are suited to low heat demand areas such as hallways, bathrooms and small bedrooms, whilst the 2.55kw and 3.4kw models are more suited to living / lounge areas, kitchens and larger bedrooms. Because their consumption is so high, Storage Heaters rely on cheaper electricity tariffs such as Economy 7 because daytime rates would make their use prohibitively expensive. Economy 7 is a tariff which refers to cheaper overnight electricity sold by Electricity Utlility Companies at around 25% – 40% cheaper than their usual daytime rate.

Electricity companies  can afford to sell Electricity cheaper, because nuclear power stations cannot be simply turned off during the night when electricity demand drops significantly, and since Electricity cannot easily be stored it is sold cheaply in order to encourage the use of Electric Heating, such as Storage Heaters. Unfortunately, this cheap rate Electricity does come at a cost, because on an Economy 7 tariff, although you will get a vast reduction in your overnight Electricity costs, your daytime electricity will be sold at a much higher price than on a standard tariff, in order to recoup some of that Economy 7 concession!.

For this reason, it is a good idea, to not only use your Storage Heating overnight, but to also users timers so that other high current appliances can work during the Economy 7 period and take advantage of the lower electricity prices, these could include Washing Machines, Tumble Dryers, immersion heaters. Even charging up your mobile phone or laptop overnight will save a little bit of money over the course of a year.

So how do Storage Heaters work?. Well, the idea was that Storage Heaters would use overnight electricity to store heat which can then be convected to warm a room or area during the day. Storage Heaters are packed with bricks, in which electric elements are embedded, the elements heat up overnight during the 7 cheap rate hours refered to as Economy 7, the heat is transfered into the bricks, where it is stored for later use.

Storage Heaters have a good level of internal insulation to maintain the heat and ensure that as much heat as possible  is transfered into the bricks, however there does remain a small amount of heat transfered from the storage heater case into the room, which will help to warm the room a little overnight and during the morning.

The main heat from the storage heater is controlled by a mechanical damper, which controls a flap at the top of the heater often controlled by a control knob marked as ‘output’, turning this control from 1 to 10 controls how wide the damper opens and how much heat convects into the room. Turning the control to ‘1’ will close the damper, and turning it to ’10’ will fully open the damper, allowing the heat to escape from the storage bricks and into the room. warming it.

For this reason it is important to make sure that the ‘output’ control is set to its minimum position when the storage heater is due to heat up overnight, if it is left open then the heat will simply transfer directly from the heating element and transfer into the room, meaning only a small amount will be stored in the storage bricks and retained for later use, ultimately meaning that your room will be toasty warm during the night and when you awake in the morning, however there will be no heat left for the Afternoon and Evening as the bricks will have not received a full heat ‘charge’.

A second control is often fitted to modern heaters, marked ‘input’ this is essentially a thermostat which controls electrically the amount of heat which is stored in the bricks, the higher the setting the higher the amount of heat stored in the storage bricks, meaning the heater will keep warm for longer and output heat for a longer period during the day, however a high setting will ultimately mean more electricity consumption. Its a delicate balance deciding what to set the input control on the storage heater to, needless to say if you get it wrong it could be far colder during the later stage of the day than you had wished, however if the weather suddenly turns milder, you may have paid for lots of heat into the bricks, which is then going to waste as you have no need for it on a milder day than was forecast.

Storage Heaters are problematic in this sense, as you cannot switch them on / off as required to give real time heat, you always have to be predicting the weather, and since they only run during the night, if you didn’t switch them on the night before, then you will have no heat the following day, equally if you switched them on the night before and it is warm and sunny the following day, then you may need to open windows if the room becomes too warm and the heat (and electricity) would have essentially been wasted.

The other negative in relation to storage heaters is that during the Evenings there may not be sufficient heat left to warm the room during the colder months, meaning that additional heating has to be used to boost the dwindling output, and since daytime peak rates are more expensive on Economy 7 tariffs than standard electricity so care and consideration should be used as to what type of Electric Heating is used to supplement the Storage Heaters, and budget accordingly.

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