Anton Evo 3 Boiler Efficiency

[ed2020]

Hi,

This may well be a stupid question (trainee gas engineer so I have many of them)!

I have just purchased an Anton Evo 3 flue gas analyser and am getting to grips with its various functions. I don't quite understand some of the readings I'm seeing for efficiency. There are three readings I can toggle through: Gross Efficiency, Net Efficiency and Net Efficiency HE.

Am I correct in saying the first two should be used for non-condensing boilers and the last one should be used on newer condensing boilers?

I've just tried the device on my boiler (a Baxi condensing boiler) and tried toggling between the three efficiency readings. The two net efficiency readings were in the nineties but the gross efficiency was down in the eighties. Why is gross efficiency lower than net?

My training has covered CO/CO2 ratios, COppm but we haven't talked about boiler efficiency readings on FGAs.

Thanks,

Ed.

 

[muggles]

First thing to know is that they aren't boiler efficiency readings, they're combustion efficiency readings. A 40 year old cast iron floor standing boiler can still give you an efficiency reading of 85% on your analyser even though the boiler efficiency might be only 60%, for example.

You're measuring the percentage of complete combustion, effectively.

 

[ed2020]

Ah! Thank you, that makes more sense. Much appreciated.