Our boiler contractor is giving us the Nett efficiency but someone said that the Gross efficiency gives a better indication of how a boiler is performing?
Which figure is best to look at for an indication of whether or not there could be a problem?
Posted in Questions
Similar Posts you may be interested in ...
- Seasonal efficiency of commercial condensing gas boilers?
- my home has a low temp,high efficiency boiler attached to an outside chimney.acid is present.Why?
- Residential Boiler System?
- Recently Installed Boiler Does Not Work, Installer does not answer phone calls. What should I do?
- where can I find reviews on high efficiency condensing boiler?
2 Responses to “Can anyone please give some advice on boiler efficiency testing?”
|
|
||||
To be honest Stephen, this is best left to someone who knows what they are doing, you could easily be mislead. Good luck.
I am not sure what is meant by net or gross efficiency other than making the calculations based on the net or gross heating value of the fuel. Also it is not clear what the problem is that you are trying to address. Is it a guarantee problem or a lost of performance over time question?
As I am sure you know the gross heating value of a fuel is based on the energy released when you burn the fuel.
The net heating value deducts the energy lost from the heating of the water vapor that is produced either by the combustion process or in the case of coal the moisture content of the coal.
The use of the net heating value will result in a calculation showing a larger efficiency since the denominator of the final calculation will be smaller. Likewise using the gross heating value will result in a lower efficiency.
If you are trying to compare the actual performance with the guaranteed performance, the basis for the guarantee should state which heating value to use.
For comparison purposes of time neither is best, you can use either one as long as you are consistent.