The truth about high efficiency condensing boilers is they aint efficient:

[guskz]

Condensation is needed for high efficiency boilers and it only occurs if the flue gas temperature is below 120deg F, so to lower the temperature they bring in cold winter air (which obviously defeats any heat savings) when the boiler is running extra hot in winter.

READ BELOW. (*****the lower the stack temperature the more effictive the heat exchange.....****)

QUOTE:

"Stack Losses:

Stack temperature is a measure of the heat carried away by dry flue gases and the moisture loss. It is a good indicator of boiler efficiency. The stack temperature is the temperature of the combustion gases (dry and water vapor) leaving the boiler and reflects the energy that did not transfer from the fuel to the steam or hot water. The lower the stack temperature, the more effective the heat exchanger design, and the higher the fuel-to-steam efficiency."

[zero]

Ya know, I never looked at it like that. Nice work! Congratulations!

-zero

[Oscar_Lives]

Really? I'll bet you have a lot of other stupid shit in your garage.

What a f****ng Einstein!

[guskz]

nice that you still live.

Instead of fowl words, the appropriate path is to show where my words don't agree with the quoted statement on boiler efficiency also posted together.

THEY say the lower the stack temperature the more efficient the boiler: are they lying, no.

The chimney to bring in air is the same size as the chimney to bring out air, so if you're bringing in air that is very cold (--10degF) ....don't you think it's going to affect the stack temperature (and the air going out....instead of hot 140deg F) ????

And don't you think bringing in cold air defeats any efficiency gain?

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I guess the best way to prove it... is to remove the pipe for the air intake and point to inside the boiler room in winter and if the air leaving the chimney is suddenly very very hot then you got your answer (that is if the plastic 3 inch chimney doesn't melt first).

[Oscar_Lives]

Try removing the exhaust pipe in the boiler room and sit there for an hour or so and see if the temperature gets colder.