How much do convection heaters cost?

torcherer

I have a silvercrest convection heater from Lidl, was planning to use it this winter as it heats up the room much quicker than the central heating. My brother claims he had one and it cost 5 euro an hour, this seems way too expensive to me. I thought these were energy efficient?? Does anyone have one, is it very dear to use? Is it dearer than your central heating?

Wearb

It's almost 100% energy efficient. That is different than being cheap to use. Electricity used like this is very efficient, in that all of it is utilised in supplying heat. Trouble is that electricity is an expensive source of heat.

To explain: -and these are not real figures- if electricity costs 20c per 1kw of supplied heat and it is 100% efficient, then 1kw worth of heat will cost you 20c per hour.

Now if oil cost 6c per kw of supplied heat and it was 80% efficient, then 1kw worth of heat would cost 7.2c per hour.

Those figures are roughly correct, but oil would drop below 80% if you were just heating one room, but would still probably be cheaper than electricity.

A 2kw electrici heater would cost about 40c per hour to run. If the room was small and well insulated, each subsequent hour after the room warmed up would be slightly less than the first hour.

TPM

the running costs are fairly easy to work out
there will be an information/data plate or sticker on the heater some where this will show the kw rating of the heater either im watts (w) or kilowatts (kw)

say it is 2300w or 2.3kw
multiply this by the unit (kw) cost of electricity 20cent approx

2.3kw
20 cent
46 cent per hour

there is no way it could cost €5 per hour to run a heater

the standard main fuse is 63amp allowing just under 15kw which would cost €3 per hour any more would blow the main fuse

editorsean

Although electric heaters are 100% efficient at converting electricity to heat (1kWh electricity = 1kWh heat), convection heaters tend to be the least efficient at heating a room compared to other heaters such as fan heaters. On the plus side, they are cheap to purchase and silent (no fan).

As air raises up from the convection heater, it heats from the ceiling downwards, so by the time the heat reaches the occupants (particularly when seated), some of that heat will have escaped through the upper walls and ceiling of the room. By the time the occupants are comfortably warm, the upper part of the room will be several degrees warmer, again accelerating heat loss through the ceiling compared to if the room's air was evenly warmed.

For comparison, an oscillating fan heater is probably the most efficient type of portable heater for evenly heating a room. It blows warm air back and forth, so the air surrounding the seated occupants will warm just as quickly as the air reaching the ceiling. On the other hand, this type of heater tends to be the most expensive type to purchase (particularly the ceramic type) and can be noisy. Anyone who has used a desiccant dehumidifier has probably noticed how effective they at heating a room as a side effect. Although the heater inside is only about ~650 watts to regenerate the desiccant wheel, the oscillating louvre distributes this warm dried air evenly about the room.

Other types of heaters can be more or less efficient at keeping the occupants warm depending on the situation. For example, a halogen heater works great for short term or spot heating, but is inefficient at actually warming a room. Most of its radiated heat gets absorbed by the walls, drawing away heat to the adjacent room or outside for an external wall.