Intergas Xtreme 127.6% Efficiency

[machineage]

Hi all!

So I've been wondering for a while if Intergas would release a boiler with a secondary HX for flue gasses - and now it has!

http://www.intergas-verwarming.nl/wp-content/uploads/2017/09/Intergas-flyer-XTREME.pdf

The Intergas Xtreme 36 is claiming an efficiency for DHW of 127.6% - how do you get more out than you put in

Looks like this will be the boiler I will be getting if customer feedback is good. Does anyone know when it is likely to be available in the UK?

Thanks!

 

[bernardgreen]

The Intergas Xtreme 36 is claiming an efficiency for DHW of 127.6% - how do you get more out than you put in

There is a qualifier attached to the 127% which should always be included when quoting efficiency.

"127.6%(hi) " where the (hi) identifies the algorithm ( fiddle factor calculation ) applied to the less than 100% efficiency that is actually achieved. Intergas seem reluctant to provide information about the (hi) algorithm.

Other manufacturers have their own algorithms.

 

[Dan Robinson]

Because, Intergas don't have a hi algorithm. The test house does.

 

[pete50]

Good grief you lot will be claiming the earth is round next.

 

[bernardgreen]

Because, Intergas don't have a hi algorithm. The test house does.

Who devised the test procedure, was it a case of the test house verified the efficiency using a test procedure written by the manufacturer.

Either way the test procedure use for the testing should ne made public, otherwise the value 127.6%(hi) is meaningless.

Heating 100 litres of water in one continuous draw will achieve a much higher real efficiency (*) than heating 100 litres of water in 20 draws each of5 litres separated by a few minutes.
( between draws the mass of the heat exchanger and the water in it will be cooling down, that heat energy being lost to the atmosphere )

(*) real efficiency is calculated from the amount of gas burnt, the calorific valuc pf the gas, the volume of water heated and the temperature rise of that water.

 

[Dan Robinson]

 

[John D v2.0]

You can get one of those copper soil stack heat exchangers for about 800 pounds and pre heat the incoming supply to get "better than 100% efficiency", or cheaper to run your water main from next doors Combi.

 

[machineage]

Thanks for the replies!

So does anyone know if or when this boiler might be available in the UK?

Thanks

 

[Dan Robinson]

@Razor900?

 

[hard-work]

I do believe latent heat is not taken into account, so when it is, efficiencies of over 100% are achieved.

 

[fixitflav]

You can get one of those copper soil stack heat exchangers for about 800 pounds and pre heat the incoming supply to get "better than 100% efficiency", or cheaper to run your water main from next doors Combi.

This subject has been discussed at length on this forum. Efficiency can be better than 100% if the heat input is based on net calorific value (NCV). But not 127% as GCV/NCV for natural gas is about 1.11. So even if there are zero losses efficiency is 111%. And you pay for gas on a GCV basis.

 

[bernardgreen]

So even if there are zero losses efficiency is 111%

If the temperature of the flue gases leaving the flue terminal is higher than the temperature of the air being drawn into the air intake then some of the heat produced by burning gas is heating air and not water. If heat is leaving via the flue then the boiler's efficiency is less than 100% ( absolute )

Intergas Xtreme 127.6% (hi) Efficiency

The modifier (hi) has to be included with the headline catching ( and mis-leading ) claim of 127.6%

I wonder what quality of boiler would have an efficiency of 100 % (hi).

 

[fixitflav]

If the temperature of the flue gases leaving the flue terminal is higher than the temperature of the air being drawn into the air intake then some of the heat produced by burning gas is heating air and not water. If heat is leaving via the flue then the boiler's efficiency is less than 100% ( absolute )

Exactly, in that case the losses aren't zero. If the temperature are equal, efficiency = 100% (GCV input)

 

[Gasguru]

I've calculated my extra jumper is equivalent to an upshift in boiler efficiency of 30%...that beats all your nonsense test house figures.
You eco nuts have lost the plot

 

[fixitflav]

I've calculated my extra jumper is equivalent to an upshift in boiler efficiency of 30%...that beats all your nonsense test house figures.
You eco nuts have lost the plot

Do you mean you believe the 127.6% claim? If you have access to the calculation method please post it. Not sure what being an eco-nut as to do with it (not that I'm admitting to that)