Condensing Boiler Efficiency

[Wiredcharlie]

Please correct me if I'm wrong, but it would appear that the more efficiently the boiler is working, the more condensate will be produced per unit of gas.

Is there an established way of calculating the real world efficiency of a condensing boiler by measuring the condensate output and the gas input?

Just wondered...

Tony

 

[Steelmasons]

CO2% in flue gas plays a considerable role.

 

[oilboffin]

Flue gas analyser Samples the gas checking co2 co and02 it's all to do with the ratio between these
Gasses the machine then calculates the efficiency and then gives the results.Not a lot to do with condensate which could also be influenced by the humidity of the air intake.

 

[Terrywookfit]

Flue gas analyser Samples the gas checking co2 co and02 it's all to do with the ratio between these
Gasses the machine then calculates the efficiency and then gives the results.Not a lot to do with condensate which could also be influenced by the humidity of the air intake.

Do you mean co / co2 ratio...........

 

[bernardgreen]

Basic science would suggest that efficiency is the amount of heat energy transferred to the water compared to the amount of energy that could be produced by combustion of the gas.

 

[Terrywookfit]

Basic science would suggest that efficiency is the amount of heat energy transferred to the water compared to the amount of energy that could be produced by combustion of the gas.

That is determined by appliance design.
Combustion efficiency can drift.

 

[bernardgreen]

Combustion efficiency can drift.

Which is why some boilers are rated as being more efficient than others.

A given volume of gas will produce a defined amount of heat energy. If all that energy is transferred to the water then the boiler is 100% efficient. If the flue gases are warmer than the air taken into the combustion chamber then the boiler is not 100% efficient

 

[gigz]

Just go to the pub instead

 

[Terrywookfit]

Which is why some boilers are rated as being more efficient than others.

A given volume of gas will produce a defined amount of heat energy. If all that energy is transferred to the water then the boiler is 100% efficient. If the flue gases are warmer than the air taken into the combustion chamber then the boiler is not 100% efficient

No s hit Sherlock !!

 

[Wiredcharlie]

Anyway, back to the question, which was:

Is there an established way of calculating the real world efficiency of a condensing boiler by measuring the condensate output and the gas input?

 

[bernardgreen]

I suppose if you collected all the water produced by combustion then you could determine the "efficiency" of the combustion process. That would provide an indication of what percentage of the hydrogen atoms in the gas molecules were being combined with oxygen atoms to produce water. That would mean collecting the condensate from the boiler and the water in the plume. The ratio of condensate to water in the plume might give an indication of the efficiency of transfering heat from combustion to heat exchanger to water.

So in theory the answer to your question is No

That said manufacturers may, based on results of testing, have produced tables of figures that give a rough indication of boiler efficiency based on the amount of condensate that the boiler produces.

 

[gigz]

You don't need gasmen/plumbers, its a scientist/chemist you really need to be asking (why do you want to know ?). There's too many variables to get an accurate answer without thousands of pounds of gear.

 

[Steelmasons]

I suppose if you collected all the water produced by combustion then you could determine the "efficiency" of the combustion process. That would provide an indication of what percentage of the hydrogen atoms in the gas molecules were being combined with oxygen atoms to produce water. That would mean collecting the condensate from the boiler and the water in the plume. The ratio of condensate to water in the plume might give an indication of the efficiency of transfering heat from combustion to heat exchanger to water.

So in theory the answer to your question is No

That said manufacturers may, based on results of testing, have produced tables of figures that give a rough indication of boiler efficiency based on the amount of condensate that the boiler produces.

Google......
What are you trying to prove Bernard?..without google I guess we wouldn't hear a peep out of you...

 

[bernardgreen]

Google......

School days chemistry and physics and knowledge from a chap whose career was designing heat exchangers far more complicated than a domestic heating boiler.
Why not offer constructive critique of the information rather than purile attempts to discredit the person.

 

[Wiredcharlie]

Bernard - you have grasped my point - ignore the noise!

Methane + Oxygen -> Water Vapour + Carbon Dioxide

If all the Water Vapour condenses in the boiler, then the boiler is working as efficiently as it can. (Presumably the manufacturer quoted efficiency).

As you say, manufacturers may have produced tables relating condensate and gas to efficiency. Anyone got one?

Tony