I don't understand the \"why\"?

heatguy

your new furnace removes almost all of heat from combustion process which means the flue product temp drops, air at certain temps can hold only so much moisture which means when you cool flue product below a certain point the moisture comes out therefore your water.your old furnance just sent the moisture up the stack to the great outdoors due to its higher flue temp

Brian_58

I just had a 95% efficient furnace put in without a humidifier. I got to thinking and I can't get my brain around it.... why does the furnace need a drain? This thing honestly drains about a gallon every 2 days (i ran the drain to a bucket until I can drill into my crawl space to attch to the main drain) and I can't see the physics on where it all comes from?!?! My old 80% unit didn't drain anywhere?

Brad White

Yup

Condensing furnaces are called that for a good reason

When gas is burned it creates carbon dioxide and water vapor as the principal components. The cooler that flue gas is driven, the more condensation you get.

Typically you will get about one gallon per 100 MBH burned. A gallon every two days? Does not sound like she is working too hard.

I would not connect this to a sanitary drain unless you first neutralize it and connect it per code via an indirect waste receptor which is both trapped and vented.

This is for a few reasons:

1) If you line is cast iron, you will dissolve it over time.

2) If your waste line is improperly connected that is a health hazard.

3) If your waste line has any chlorine in it (laundry) and that enters the combustion chamber, that will aggressively attack stainless steel.

jp_2

wrong text book

try chemistry:

burn a hydrocarbon and you end up with free hydrogens H that attach to free oxygens O, and other stuff too.

bingo 2H + O = h20 water!!!!!!!!!

natural gas, mostly methane CH4:

burn:

CH4 + O2 = H2O + CO2 not balanced for easy of understanding

Hvacman

But,

fuel gas is not pure hydrocarbon... it's not the water that gets you, it's all the other stuff found in the products of combustion...

mtfallsmikey

What y'all really want to say is..

Condensate from burning fossil fuels is acidic.

jp_2

wood too!

i have paper thin stove pipe to prove it!

Mitch_4

wood

is a fossil fuel

Weezbo

when it finally dawns on people....

where the mysterious chemicals went , will be no big secret ....

take a look at aeroport emissions...it will present a veritable CLUE.

jp_2

everything then?

are you saying that everything organic is fossil fuel?, apples, bananas, soil,grass,cows,people?

whats your definition of fossil fuel?

Mitch_4

no, my bad,

but in my momentary mind fart I was thinking that because you can "make" charcaol from wood...wood is a carbon based (i know almost everything is) fuel.

Besides...ever try to light a banana? and the glow at christmas time in the fireplace just isnt the same..;-}