Two oil filled radiators versus 1

[la fluer]

Hi all,

we have a large open room which is approximately 23sq metres.

Currently it is heated by a singll Delonghi Dragon 3 heater. Once warm it is very well insulated but obviously takes a long time to heat with just the one heater. What I am considering is putting in a second heater, whilst this would be two units drawing power as it would heat quicker and maintain a constant temperature easier my thinking is this would ultiamtely save money (on what is an expensive method of heating).

Can anyone confirm my thoughts are sound?

Thanks

La Fluer

[Paul Drawmer]

la fluer said:

...Currently it is heated by a singll Delonghi Dragon 3 heater. Once warm it is very well insulated but obviously takes a long time to heat with just the one heater. What I am considering is putting in a second heater, whilst this would be two units drawing power as it would heat quicker and maintain a constant temperature easier my thinking is this would ultiamtely save money (on what is an expensive method of heating)...

I'm assuming both heaters have thermostats.

Think of it as a power problem.

You need to put X amount of Kwh in to get the room up to temp. Apart from heat losses whilst the target temp is being reached, it will take the same amount of power to do this however many heaters you have. It's just that with more heaters you can get the required amount of heat in quicker (more Kw over less h)

If one heater can maintain the temp level, using two would only make the rise part of the heat cool cycle quicker.

In any case, one of the heaters would have the 'stat set lower than the other (since it would be practically impossible to synchronise them) so chances are that nearing the target temp, only one will be working anyway.

So..I reckon it will cost the same with two heaters, but be more convenient.

[la fluer]

Thanks! Yes I realised it would require the same amount of power on the heat cycle but as it gets so hot with just the one radiator (maintains heat) I had hoped that it might prove slightly more efficient to maintain the heat with the 2 but then I guess half the power requirement x 2 radiators cancels that out. So the only benefit would be quicker heat up times?

[Mr GrimNasty]

Best not to plug more than 3kW into one socket (double or not).

[Phooey]

Mr GrimNasty said:

Best not to plug more than 3kW into one socket (double or not).

I've just found this out. Made the trunking (containing the cable to the double plug socket) very warm

[Simpo Two]

la fluer said:

I had hoped that it might prove slightly more efficient to maintain the heat with the 2 but then I guess half the power requirement x 2 radiators cancels that out.

That's a point - is the efficiency of a heater linear as output rises or is there, like a car, an optimum setting in terms of power used vs heat out?

[LaFleur]

I guess I can get a second heater and two energy monitors and see what happens. Is heat like sound with a nice log calculation so 1dB increase = 3 times louder (I know that is not accurate!). We have our main gas heating on all the time, takes initially more to get to the full temp but then less to keep it at a nice warm temp than keep firing up on full every few hours.

[Paul Drawmer]

I still think the thermostats on those things are too crude to be able to align a pair so that two heaters work properly to maintain the room temp. I reckon one will do most of the work.

[herewego]

LaFleur said:

I guess I can get a second heater and two energy monitors and see what happens. Is heat like sound with a nice log calculation so 1dB increase = 3 times louder (I know that is not accurate!). We have our main gas heating on all the time, takes initially more to get to the full temp but then less to keep it at a nice warm temp than keep firing up on full every few hours.

The only reason for leaving your heating on all the time(assuming you sleep at night) is when your heating system can't get the rooms up to temp within a reasonable time. It costs more to keep the heating on all the time than to turn it off when you don't need it. This is simply because the heat loss from the building is directly related to the differential temperature between the inside and outside air .

[herewego]

Simpo Two said:

la fluer said:

I had hoped that it might prove slightly more efficient to maintain the heat with the 2 but then I guess half the power requirement x 2 radiators cancels that out.

That's a point - is the efficiency of a heater linear as output rises or is there, like a car, an optimum setting in terms of power used vs heat out?

An electric heater converts all of the electricity it draws into heat so, irrespective of the output level, its electricity to heat conversion is 100% efficient. Unfortunately we can't say the same about the power station that produced it which is why it's relatively expensive.

[davepoth]

herewego said:

Simpo Two said:

la fluer said:

I had hoped that it might prove slightly more efficient to maintain the heat with the 2 but then I guess half the power requirement x 2 radiators cancels that out.

That's a point - is the efficiency of a heater linear as output rises or is there, like a car, an optimum setting in terms of power used vs heat out?

An electric heater converts all of the electricity it draws into heat so, irrespective of the output level, its electricity to heat conversion is 100% efficient. Unfortunately we can't say the same about the power station that produced it which is why it's relatively expensive.

No it doesn't - A heating element will glow red/orange once it gets got, that's a bit of a waste of energy.

[herewego]

davepoth said:

herewego said:

Simpo Two said:

la fluer said:

I had hoped that it might prove slightly more efficient to maintain the heat with the 2 but then I guess half the power requirement x 2 radiators cancels that out.

That's a point - is the efficiency of a heater linear as output rises or is there, like a car, an optimum setting in terms of power used vs heat out?

An electric heater converts all of the electricity it draws into heat so, irrespective of the output level, its electricity to heat conversion is 100% efficient. Unfortunately we can't say the same about the power station that produced it which is why it's relatively expensive.

No it doesn't - A heating element will glow red/orange once it gets got, that's a bit of a waste of energy.

Where does it go?

[Paul Drawmer]

herewego said:

davepoth said:

herewego said:

Simpo Two said:

la fluer said:

I had hoped that it might prove slightly more efficient to maintain the heat with the 2 but then I guess half the power requirement x 2 radiators cancels that out.

That's a point - is the efficiency of a heater linear as output rises or is there, like a car, an optimum setting in terms of power used vs heat out?

An electric heater converts all of the electricity it draws into heat so, irrespective of the output level, its electricity to heat conversion is 100% efficient. Unfortunately we can't say the same about the power station that produced it which is why it's relatively expensive.

No it doesn't - A heating element will glow red/orange once it gets got, that's a bit of a waste of energy.

Where does it go?

Light

[herewego]

Paul Drawmer said:

herewego said:

davepoth said:

herewego said:

Simpo Two said:

la fluer said:

I had hoped that it might prove slightly more efficient to maintain the heat with the 2 but then I guess half the power requirement x 2 radiators cancels that out.

That's a point - is the efficiency of a heater linear as output rises or is there, like a car, an optimum setting in terms of power used vs heat out?

An electric heater converts all of the electricity it draws into heat so, irrespective of the output level, its electricity to heat conversion is 100% efficient. Unfortunately we can't say the same about the power station that produced it which is why it's relatively expensive.

No it doesn't - A heating element will glow red/orange once it gets got, that's a bit of a waste of energy.

Where does it go?

Light

Obviously, and I suppose if you pointed the glowing element at the window then a bit of light would escape so I guess in that case you're right but otherwise it would be absorbed by whatever surfaces it hit. I suppose you could also argue that some tiny fraction could reflect off the ceiling or whatever and head for the window.

[Simpo Two]

Paul Drawmer said:

Light

Put a solar panel in front of it

[LaFleur]

Simpo Two said:

Paul Drawmer said:

Light

Put a solar panel in front of it

Solar panel -> heater -> Solar panel, free heat