Electromax efficiency question

[MM33]

Hi all,

I own an electromax electric boiler.
According to its datasheet which can be found here:
https://www.heatraesadia.com/-/medi...atraesadia_datasheet_electromax_lr_output.pdf

It has "99.8% boiler efficiency and integrated economy controller"
However further down, in the same document there is:
Seasonal space heating energy efficiency class D
Seasonal space heating energy efficiency (%) 37

My question is, out of every 1 kwh input, how much heating (in kwh) is produced ?

Thanks.

 

[stem]

With regards to heating, electricity is generally considered to be 100% efficient, you put in 1kW of electricity and you get 1kW of heat out. I guess the 99.8% is less 0.2% that isn't converted into heat and is instead used by the controls to operate the system.

 

[MM33]

Thanks Stem,
What is "Seasonal space heating energy efficiency" ? and why is rated D if it is 99.8% efficient ?

 

[endecotp]

why is rated D if it is 99.8% efficient ?

Because it's electric.

I suspect, but do not know, that the 37% efficiency is related to the hypothetical typical efficiency of the (gas-powered) power station providing the electricity. So it's in some sense comparable with the efficiency of burning the gas yourself in a gas boiler to make heat directly.

 

[stem]

What is "Seasonal space heating energy efficiency" ? and why is rated D if it is 99.8% efficient ?

You didn't ask that

My question is, out of every 1 kwh input, how much heating (in kwh) is produced ?

To be honest I thought you would ask that, and I would want to know, but unfortunately I can't tell you.

 

[Terrywookfit]

Thanks Stem,
What is "Seasonal space heating energy efficiency" ? and why is rated D if it is 99.8% efficient ?

Generating and transmission losses.?

 

[echoes]

Because it's electric.

I suspect, but do not know, that the 37% efficiency is related to the hypothetical typical efficiency of the (gas-powered) power station providing the electricity. So it's in some sense comparable with the efficiency of burning the gas yourself in a gas boiler to make heat directly.

That appears to be correct. The rather opaque calculations assume that the electricity generation is 40% efficient, and combined with other factors, we get to 37%.

Although a modern combined cycle gas fired power station is significantly more efficient than that.

 

[MM33]

Thanks everyone.