Quick question on electric heaters?

Naf

I have E7 and storage heaters in new house. While I know how how this will be best used in winter, I'm pretty certain using one or two electric heaters as and when needed will be cheaper for spring/summer nights if it's chilly.
Overnight, 7 hours at 3.5 kW and 6.97p per unit = £1.70per day
Vs. Evenings up to 3 hours at 2kW and 13p per unit = 78p per day.
So I could use 2 heaters and still save, especially given it will be a rarely used convenience compared to charging the heater every night just in case.
Simple question: which will make the room feel warmer faster, convection, ceramic or oil filled?
I know the same power rating will use the same electricity in the same time, but I'm sure that an oil filled radiator will take time to heat the oil first: a waste given that I just want a quick top-up for an hour or two.
Ideas?

HappyMJ

You need a cheaper rate. If you are going to use storage heaters extensively then paying 7p/kWh as a night rate is very expensive. My night rate is 4.5p/kWh and I don't use night storage properly at all. I only use it for hot water including overnight and morning heating (just before E7 switches to standard).

Your day rate is good at 13p mine is 15.15p.

The convector heater will heat the room faster and will not be on maximum for the entire 3 hours. It will be too warm. It only needs a quick burst for 15 minutes or so.

The oil filled rad or ceramic rad will take 15 minutes to heat itself up then once you leave the room it will continue to heat the room once it is turned off which in my opinion is wasted heat. But you have figured that out already...I do use an oil filled rad for the bedroom. It's only 800W. It gives a nice smooth safe background heat all night for little cost. It's not warm by any standard but it keeps the temperature steady and pleasant to sleep with.

Cardew

Naf wrote: »

Overnight, 7 hours at 3.5 kW and 6.97p per unit = £1.70per day
Vs. Evenings up to 3 hours at 2kW and 13p per unit = 78p per day.

In your comparison you are making the assumption that the storage heater has to receive the full 7 hour charge @3.5kW.(24.5kWh)

You can of course turn the input control down and store, say, 8kWh. How much heat will be left by evening depends on how much of that heat 'leaks' during the day - with the output control at minimum.

Also, as stated above, 6.97p/kWh is a very high price to pay for off-peak.

Naf

Cardew wrote: »

In your comparison you are making the assumption that the storage heater has to receive the full 7 hour charge @3.5kW.(24.5kWh)

You can of course turn the input control down and store, say, 8kWh. How much heat will be left by evening depends on how much of that heat 'leaks' during the day - with the output control at minimum.

Even with the output set to minimum it leaks so much that there's very little heat left for the evening: the surface gets warm, but not hot and consequently it doesn't really heat the room.
Plus I can see that through the summer the heat leaking during the day will just make the house unbearable on a warm day.

Cardew

Naf wrote: »

Even with the output set to minimum it leaks so much that there's very little heat left for the evening: the surface gets warm, but not hot and consequently it doesn't really heat the room.
Plus I can see that through the summer the heat leaking during the day will just make the house unbearable on a warm day.

I wasn't disputing that it makes sense to use a non-storage heater for a couple of hours in the evening, rather than a storage heater. Some people do that on an evening even when they have Gas CH.

However you are over-stating the case by using a costing for 24.5kWh on off-peak in a comparison.

You have illustrated one of the problems with Storage heating, namely that you have to try and forecast your heating requirement for the next day.

Naf

Exactly.
The reason I used the full charge for my calculation is because I have to charge it fully just to have any heat leftover in the evening. So a full charge is what I would have to do as an alternative to a room heater.
What I really want is a battery I can charge overnight, which will then give me 2-3 hours of 2kW output from a heater lol.

Naf

Sorted. Dimplex 3kW convection heater, with a fan blower on the front. Works a treat, chill is taken off the air in under 10mins, and I can already see the difference in my meter readings.