If you aren't a properly trained and licensed HVAC contractor, or working for one, you should probably call a halt until someone knowledgeable can do this work. You dilemma sounds pretty basic. Sorry, this isn't a domain for the half-xxxxxx, and undertrained.

Thank's sir you sound like a troll. I won't be calling you for

If you're holding yourself out as being competent to do this work on your own, you shouldn't be calling anyone. Nor trying to get advice on an internet forum. Good luck.

Ok boomer. thanks for the advice.

Ah. A millennial who thinks he knows more than anyone else.

Go figure.

Maybe I should hire you. what area do you service?

What exactly is the issue with your install? What is the model number of your furnace? These furnaces are generally very similar wrt condensate management. Some have an internal trap while others don't - that's the main difference.

Well Mr. Lee, this sounds like a big conflict of interest. ( I could be wrong in that assumption.)

I'm not aching to do 3rd party, 4th party, 5th party work. I like to be in the pole position.

Plus if you're installing a condensing furnace in this climate I'm in where an 80% furnace sat before, you or whoever is paying you to do this isn't going to like my recommendation.

In other words, I control the whole operation. If you don't like those terms, I'm not going to be of any help to you.

(This may sound like an ego thing to you but it's not. It's simply smart business.)

With that said, I service mostly the west side Katy, Texas area.

I could not find how the condensate trap is supposed to be connected to the furnace in the installation manual and all I was asking was for a little help as to where I could find it at. The model number of the furnace is GMSS960803BNAA.

The furnace was bought used and I didn't pick it up

The condensate line instructions start on Page 18 in the installation manual, The condensate trap is supplied with the furnace and factory installed. You should not be adding an additional trap. You may have to change the condensate line depending whether you have a horizontal for vertical installation.

The condensate trap is supplied with the furnace and factory installed.

No... I haven't installed any condensing furnaces and can tell you that no the condensate trap is not factory installed. (Because depending on how the furnace is installed will vary the position of the trap.) If the trap is not positioned right, not installed right... the furnace will not work for long if at all.

Mike_Home is a home owner that lives in New Jersey. When you follow his instructions be sure to call him when it doesn't work. Oh wait a minute.... you can't.

Not factory installed. If the trap is not installed properly on a condensing furnace, the furnace is most likely to shut down on nuisance faults. If this condensing furnace is being installed in a humid climate (like Houston area as an example) it is likely to have a never ending stream of maintenance related problems.

In a humid climate the furnace (condensing) will make more condensation when running and will create more maintenance headaches. Humid air in = more condensation.

And that spells Trouble.

LOL.

No... I haven't installed any condensing furnaces and can tell you that no the condensate trap is not factory installed.

Hi Ray,

Did you read the installation manual? In case you didn't here is a paragraph from page 19:

I also don't install condensing furnaces for a living. That's why I refer to the installation manual of the furnace in question to help answer questions.

I really like Taylor Swift. Please post more of her songs.

Most of the time for my area furnaces are installed horizontally. But there are plenty more considerations that must be met above that of a condensate trap and or the location thereof.

Notice the top of that snippet you posted 'General Drain Information'. In a climate that is more often prone with high humidity 'General Drain Information' in most cases should be ignored.

What does high humidity climate have to do with it? Combustion air. --- humid laden combustion air will do what?

Remember this is based on science, not magic. The video was funny that's why I posted it.

" Mike_Home is a home owner that lives in New Jersey. When you follow his instructions be sure to call him when it doesn't work. Oh wait a minute.... you can't."

Says the "pro" that posts absolutely terrible info and advice on a routine basis.

Mike Home has been a source of good info and advice for many, many years and many of us have learned a lot from him. (And as an added benefit he does not post spam here!)

Says the "pro" that posts absolutely terrible info and advice on a routine basis.

The HVAC licensing board of the state I reside in says otherwise. If you want to do foolish things -- go ahead and listen to the amateurs of this forum board.

Your home is an appreciating asset, if you want to destroy it --- go for it. Yeah that's some more terrible advice for you....

"What does high humidity climate have to do with it? Combustion air. --- humid laden combustion air will do what?
Remember this is based on science,"

Austin, I think your last sentence is correct but I'm not so sure about what comes before.

I believe that most of the water in that condensate discharge comes from the combustion of the fuel, not from the air. With 80% furnaces that discharge into the air, it's common to see steam or what some think to be smoke coming from rooftop vents. It's the same thing, the moisture produced by the combustion.

When it's cool, and especially in places where it's quite cold, relative humidity is low and there's little water vapor in the air. Heat that air up and the relative humidity is even lower. Furnaces nonetheless produce liquid condensate or steam in the atmospheric vent. As a by-product of combustion.

Yes, it is science.

If you want to do foolish things -- go ahead and listen to the amateurs of this forum board.

Ray,

Are you saying reading the manufacturer's installation manual is a foolish thing?

No, he's saying " The HVAC licensing board of the state I reside in says otherwise."

If anyone here believes that having a license (to do anything) is "proof" that he or she is correct in their postings, they'd be a fool.

This forum was a great source of info just a few years ago - some of those valuable contributors were driven out by folks seeking to advertise their business and to belittle many of the forum members.

Stax, I don't think it's so bad. The ones whose learning extended past what was common in 1985 are still around. Tiger Dunes comes by from time to time and knows the biz and modern practices. So too energy rater LA (forget exact name) who's an energy rater with practical, hands on knowledge of HVAC and building science. mike home is a knowledgeable homeowner. And there are others.

There's a forum you can get to with a search including these words - hvac talk AOP residential - for a place where homeowners post questions and only pre-qualified HVAC pros are allowed to respond. The site crashed and was down for 6 weeks and is just coming back so traffic is at a lower level right now. The mantra there is that whether required by local codes or not, only hacks put in equipment without doing a load calc, and that load calcs done today on existing houses almost always show what's existing and being replaced is oversized. Also, that the installer matters more than the equipment brand chosen. I read recently some comments that that in areas of high summer humidity, a better choice is often to undersize AC and put in a whole house dehumidifier

Active responders there come from across the country - North to South, East to West - and all are of one voice about this. There's even one guy who loves doing load calcs for free. Homeowners who include enough data in a forum post, or email it to the guy, receive a load calc. Can't beat that for generosity. It's as good as the data, of course, but a stab at it is better than no stab at all. They also often refer people to other resources. .

Unfortunately, HVAC-Talk has become a refuge for sanctimonious "Pros" who are legends in their own minds (yep, they're everywhere) - they won't help the OP as they flatly refuse to engage in any DIY activities.

The OP should read the manual for his furnace which clearly states the trap is supplied with his furnace:

https://www.theacoutlet.com/documents/Installation-Guide-Goodman-GCSS9-GMSS9.pdf

Unfortunately, as he bough it used, who knows if it actually came with the trap. Traps for condensing furnaces are part of the furnace design - if the trap is not there in the furnace where the manual says it should be then he should probably buy the correct part rather than an old school P-trap.

Correct, no DIY. HVAC work is skilled, potentially dangerous (lethal!) if done wrong, and they're there to give guidance, not task instructions.

Just like the old saying that someone who represents themself in a court of law has a fool for a client, about the same is true for someone doing their own HVAC work. In my opinion. If you call your dentist about tooth pain, do you expect them to explain how to extract your tooth or clean out a cavity with the corner of a screwdriver?

The smartest people I know are the ones who are more aware of what they don't know (and don't pretend to know) than of what they do know. Only fools think "How hard can it be, I can figure it out".

No, he's saying " The HVAC licensing board of the state I reside in says otherwise."

If anyone here believes that having a license (to do anything) is "proof" that he or she is correct in their postings, they'd be a fool.

How many years do you put in doing the work you claim to know so much about?

How many years of experience / licensing of actually doing this kind of work is a requirement to offer advice on this board?

Let's read a manual, let's do heat load calcs, everything will be fine. The common theme on just about any thread you read here. Make no considerations to the climate in which the home is located.

BUT: on many posts those same actors will come in and say 'without doing a heat load' that the system is either undersized or over sized.

Let's preach to the choir and then turn into a hypocrite. If I am a fool, forgive me for revealing your fault.

Let's read a manufacturer manual. Gee if that was all I had to do to become a licensed contractor, what would the point be to become one? Licensing means nothing... so what would be the point to have a license?

The law doesn't let you drive without a driver's license. Do they? Did you not have to have training for that? What makes you such a professional driver? Reading the car manual?

Yeah Ok, I'm the fool here? RIGHT?

Experience means nothing, licensing means nothing -- read a manual when that doesn't work blame the manufacturer for making a bad product.

Your view is to claim I know everything. My view is that I claim to know more than you and I live it everyday. Not because I am some super smart guy, but because I have applied myself to my career and have done things according to the law of the land.

Don't worry, the ugly home buyers will pay you pennies on the dollar for your home. There is a way out for you. Heck I might even make a low ball offer or two.

Remember this is based on science

What is science according to the moisture content of the air?

This isn't the place for teaching there are trade schools for that.

The more humid the air is, the higher the amount of water vapor that air holds.
It's not uncommon here in winter for humidity to remain elevated for long periods of time. It can be as high as 80-90% RH or higher --- just as much as some years it may be dryer similar to other climates.

More science:

Condensation is the term for water changing state from a vapor to a liquid. The process requires the presence of water vapor in the atmosphere, falling temperature and the presence of another object for water vapor to condense around.

Requires the presence of water vapor for condensation to occur. It's not maybe or if. --- nope that would be magic.

Requires the presence of water vapor for condensation to occur. It's not maybe or if. --- nope that would be magic.

Ray,

Are you saying the condensation produced by a furnace is solely caused by the relative humidity of the combustion air? In other words a condensing furnace in Katy Texas where the where the relative humidity is 80-90% in the winter will produce 2-3 times more condensate than a furnace in NJ where the relative humidity is 30-40%?

No Mike, not solely.

HVAC is not a box with 'exact science' as a protocol.

Like everything in life, your mileage will vary due to a long list of factors and variables.

Look at the chart I posted... do you not see variables upon variables?

I don't follow "HVAC is not a box with 'exact science'..." comment. I think the laws of physics apply to HVAC in all states.

Yes I do see the chart which shows grains of water as a function of the relative humidity and temperature of the combustion air. So your position is the condensation is due to the relative humidity of the combustion air but will vary due to a long list of factors and variables?

The table is useful. It shows there is very little water vapor in cold air, even at high levels of relative humidity.

Cold air can not hold as much water as warm air, this is pretty basic science. I am sure we are all aware that natural gas holds a fair amount of water and releases this water when burned, again pretty basic.

Natural gas as a compound holds no water. Water is produced by the chemical reaction of burning. My college chemistry is more than rusty but here's the equation, thanks to a search:

CH4 + 2 O2 -> CO2 + 2 H2O + energy released

CH4 is the methane gas fuel

O2 is oxygen gas

CO2 is carbon dioxide, carbon monoxide CO is also produced

H2O is water

Austin can continue thinking the water released is from humid air.

Edit to add - for those in the grandstands, the equation shows that from this reaction each single molecule of gas produces two molecules of water.

You are correct, I stated that poorly.

I don't follow "HVAC is not a box with 'exact science'..." comment. I think the laws of physics apply to HVAC in all states.

Let do a heat load calculation... the calculation says we need an A/C to remove 'exactly: 50,000 BTU's of heat.

The manufacturer doesn't make a 50,000 BTU air conditioner. We'll put in a 60,000 BTU AC or we'll gamble and put in a 48,000 BTU air conditioner.

The thermostat on the wall says: 76 degrees and my temp drop is: 11, 15, 18, 19, 22 degrees different. (The 'RANGE' we shoot for is 15 to 20 degrees.) Not exact, but a range.

My furnace temp rise (heat coming from the vent) is: 30, 35, 40, 43, 55, 60. (above that of return temp) --- 30 to 60 degrees is the range we shoot for --- not exact -- anything but exact.

It's too hot / too cold I want exactly this much heat... (a random number).

-------

Add insult to injury: tomorrow it will be 85 degrees with 70% humidity. The next day it will be 75 degrees with 50% humidity. --- not exact ---

Tomorrow morning it will be 60 degrees... by afternoon it will be 88 degrees with 73% humidity.

Climate plays a big role and that is not exact either. (no two locations are exactly alike --- not exact.)

It shows there is very little water vapor in cold air, even at high levels of relative humidity.

How cold is cold? We're wanting to be exact here. Why? to draw a conclusion.

At a temperature of 50 degrees with 80% humidity compared to same temp and 20% humidity... what does the chart tell us?

10 grains of water in that air of 20% humidity very common for northern climate

42 grains of water in that air of 80% humidity --- over 4 times the water.

Why use 50 degrees? that is a very common temperature for my climate.

It makes little sense to say a lower temp for my climate because this climate isn't extreme in that sense (low temp extreme)

Water is produced by the chemical reaction of burning.

Sorry but we aren't talking about 'water production' here. We are talking about 'Condensation'. While it's similar as it's liquid --- the act of doing it is condensation.

Condensation is the term for water changing state from a vapor to a liquid. The process requires the presence of water vapor in the atmosphere, falling temperature and the presence of another object for water vapor to condense around.

The more moisture in the combustion air will produce more water vapor which will then condense... due to the nature of what a 'condensing' furnace does.

Under your thinking an 80% furnace would generate 'water' thru the process of burning?

No, that is not right, an 80% gas furnace has never generated any water / or condensation when properly installed. (except that it is expelled from the flue as water vapor -- IE condensation occurs out doors on the roof top / outside the building where it doesn't matter.)

Austin can continue thinking the water released is from humid air.

In that sense, I believe the term you are searching for is called RAIN.

Water is produced by the chemical reaction of burning.

Sorry but we aren't talking about 'water production' here. We are talking about 'Condensation'. While it's similar as it's liquid --- the act of doing it is condensation.
Ray,

Did you cover the chemical reaction below in trade school? Were there any questions about it on the state licensing examination? Are you familiar with the law of conservation of mass?

CH4 + 2 O2 -> CO2 + 2 H2O

This is the combustion reaction of methane in the presence of oxygen. The byproducts are carbon dioxide and water. For every molecule of methane, two molecules of water are produced. This is an exact science and works everywhere. For a given amount of methane you can calculate how much water is produced.

Where does this water go? Well if you have an 80% efficiency furnace then water goes up the chimney. If you put you hand over the chimney while a low efficiency furnace is operating you will feel the water condensing on your hand.

Condensing furnaces have efficiencies above 90%. This higher efficiency is achieved by a second heat exchanger. The heat that would normally go up the chimney is extracted. This extraction process cause the exhaust gas to cool and forms condensation. Most of this water is a result of the combustion chemical reaction. The furnace would produce condensation even if the combustion air contained no moisture. All furnaces regardless of their efficiency will produce the same amount of water during the combustion process. This is the basic law of conservation of mass. If the furnace has only one heat exchanger which is the kind you are most famiilar with, then you don't have to worry about it since it will go up the chimney. But if you are installing a furnace with a second heat exchanger then you have to provide a drain for the water produced by the furnace. A furnace in a very cold and dry climate will produce a lot of condensation. I know this by first hand experience.

If you disagree with anything I have stated, then let's discuss it using the laws of physics and chemistry. Let's also not limit ourselves to the climate of Katy Texas.

Let's not limit ourselves to the climate of New Jersey or California either....

The grains of water in the air (due to humidity) --- This air in turn is used for combustion --- this water vapor in addition to the chemical process of combustion (usually done in a lab using pure oxygen (2 O2 is my assumption as I am not a chemist, I am a HVAC contractor, not going to pretend to know something I don't unlike you and others --- as in burning something in a lab.)

But we aren't burning things in a lab are we? Where do the grains of water go that are made up of the air for combustion?

This water (in the air used for combustion) doesn't magically disappear... does it? It becomes condensation.

Here's some proof if you like (well knowing you, you probably won't like it)

Factors effecting the amount of condensation created by a 'Condensing' Furnace

Enjoy my little chemists....

You are correct, the water in the atmosphere does contribute to the condensation. I could be wrong, but I don't think anyone on the thread said it does not. The point is the amount of condensation caused by the combustion reaction can be much more than that contributed by the humidity of the air.

I am a HVAC contractor, not going to pretend to know something I don't unlike you and others

I don't have to pretend to know anything. That is why in my first post I did not pretend I knew how to install a condensate trap on a Goodman furnace. I suggested the original poster should read the installation manual.

Mike, yes they did.....

Elmer J Fudd

Natural gas as a compound holds no water. Water is produced by the chemical reaction of burning. My college chemistry is more than rusty but here's the equation, thanks to a search:

CH4 + 2 O2 -> CO2 + 2 H2O + energy released

and here: Austin can continue thinking the water released is from humid air.

Thanks everyone I love the laughs of a morning...

Typical high-efficiency furnaces will actually produce about 0.8 gallons per hour of condensate for a 100,000 input BTU furnace

Ray,

Of the approximate 0.8 gallons produced every hour, approximately how much would you say is produced due to air being at a relative humidity of 40% with a air temperature of 20F degrees?

mike, you're beating a dead horse. He doesn't understand it but he's attacking and being defensive about it all the same.

Ray,

Of that 0.8 gallons produced every hour, approximately how much would you say is produced due to air being at a relative humidity of 40% with a air temperature of 20F degrees?

It says "about 0.8 gallons" while you say an exact figure of 0.8 gallons.

You use lower humidity rate of 40% and lower temp of 20F degrees. Those are not common numbers for my climate. So why would I want to go down that rabbit hole?

As I have also said countless times: HVAC is not an exact science that you are trying to make it out to be. (The rabbit hole I will go down...)

What does 'about 0.8 gallons' imply?

It will vary. Why? Because it depends on an assortment of factors... how efficient the furnace is? is it 90%, 92%, 96%, 97% --- even if I knew what efficiency the furnace was I would be guessing as to how much.

It would also depend on humidity, heat rise, the fuel supply is it truly dry? or is there *some* moisture in the fuel supply, hot hot it is, how long the furnace must run etc.

It's one thing to be conducting an *experiment* in a lab like the chemistry equation where you control all the parameters of the *experiment*. This doesn't work in the real world. (IE: out in the field, where I actually work --- I don't work in a lab.)

You mean there *could* be moisture in the fuel mix? yeah. It's not a significant amount but moisture is moisture. We combat this problem by installing what is called a drip leg. (in some places it may be called a dirt leg or sediment trap so if you want to argue differences in terminology you can run down that rabbit hole too.)

There could be water in the gas you buy for your car. If the gas station doesn't monitor the water content of the tanks in the ground --- there's going to be people claiming they bought some bad gas from you. How does the water get into that tank? Condensation.

I've posted the definition of this condensation term at least two times. Now go back and read it.
-------------
Mr. Fudd, not attacking --- answering questions, just that you won't accept the answers, nothing I can help you with there. As it were you can lead a horse to water, but you can't make him drink it.

Why is any of this important?

(This pictured below is what it leads to in various degrees some worse than this, some not quite as bad. Ceiling cave in ) Note: this was due to AC, but people who start fooling with things they do not understand in a high humid climate --- this is ultimately where it leads..... Have fun!

PS: I service the Katy, Texas area and I fix problems like this and more.

It says "about 0.8 gallons" while you say an exact figure of 0.8 gallons.

Ray,

I edited my previous post to say "the approximate 0.8 gallons".

You use lower humidity rate of 40% and lower temp of 20F degrees. Those are not common numbers for my climate. So why would I want to go down that rabbit hole?

I thought we agreed that we were not going to limit the discussion to the climate of Katy Texas?

What does 'about 0.8 gallons' imply?

It will vary. Why? Because it depends on an assortment of factors... how efficient the furnace is? is it 90%, 92%, 96%, 97% --- even if I knew what efficiency the furnace was I would be guessing as to how much.

If you think there are too many variables then choose the indoor humidity, outdoor humidity, indoor temperature, outdoor temperature, amount of moisture in the natural gas, the temperature of the flame, efficiency of the furnace, and the latitude and longitude of the furnace location. Exact numbers are not necessary to educate everyone the source of the condensate.

I will restate the question:

Given a set of a operating conditions, what are the approximate percentages of the condensate produced by a natural gas condensing furnace when operating in the heating mode that are created by the surrounding humidity, combustion process, and other factors?

I am asking this question because there seems to be a difference in opinion of how the condensate is produced by a condensing furnace.

Water as a by-product of combustion is familiar to most people. Start a car somewhere where it's cool, or even cold (call it 10 degrees F with essentially no water vapor in the air). Water produced by the engine combustion of gasoline is held by the hot air as it leaves the cylinder. But the exhaust manifold and exhaust system are cold and the exhaust gas is cooled. That lowers the water vapor holding capacity of the exhaust air and so what comes out the tailpipe is cooled exhaust that looks like white smoke because the cooled air can't hold it. Water vapor. Sometimes water drips out the pipe too, condensate. Run the car for 10 minutes, the hardware warms up, and the exhaust gas stays hot as it exists the tailpipe and can hold the water vapor in the normal way. "Steam" is no longer visible coming out the tailpipe.

I thought we agreed that we were not going to limit the discussion to the climate of Katy Texas?

Well the OP who started this thread made it sound like he lived near me... which would mean using my climate numbers as opposed to somewhere else.

I don't service areas outside my climate so why on earth would I entertain this idea of yours?

(I offer advice on occasion but that is all it is --- professional advice --- as this is what I do for a living, I don't sit all day in forum board --- I do have a life outside of HVAC, what little it is right now it's still a life...)

You again trying to fit HVAC in a confined specific box in which it does not fit.

What are the odds that someone will find that information useful? Probably close to 0% if I had to guess. That sounds like a waste of time... I know this seems productive to you so knock yourself out if you want to do that.

Exact numbers are not necessary to educate everyone the source of the condensate.

Then why not use the 'about 0.8 gallons estimate' and run with it? An air conditioner in my climate can produce upwards of 5 gallons of water an hour. A condensing furnace will not produce that much. An 80% non condensing furnace will produce 0 condensate water.

Oh so let's use the AC condensate line for the furnace condensate. Problem solved right?

Most likely not. Drain systems are complex especially when you throw in the variable that a condensing furnace imposes.

See I've led your hand to this point --- where the concern right now up to this point is how much more condensate a condensing furnace will produce in my climate Katy, Texas versus other less humid climates in which those furnaces are installed typically in a basement. You don't have the over head flood threat you do here in my climate.

All of this --- except: there are safeties on that condensing furnace that if you don't do it properly, the furnace will shut off on nuisance trips. So the furnace is not likely to be the cave in threat due to condensation production.

They tend to leak water in drips around the furnace while having very erratic operation most often. You don't get these kinds of problems with a 80% non condensing furnace.

What a home owner knows versus that of a pro... you think condensate is the only problem you have to contend with. What is your definition of making this actually work?

How does the condensing furnace then become the ceiling cave in threat? Changes to the condensate drain system by people who don't know what they are doing.

It may be a home owner, land lord or even a technician who doesn't understand the implications of what they are doing.

How much water one produces whether here in this climate in Katy, Texas or a less humid climate (in winter) like Chicago / Wisconsin --- the different in condensate production doesn't matter...

*IF* the system to get rid of condensate is adequate.

This thread was about a young guy presumably in his 20's attempting to install a condensing furnace in a probable high humid climate.

That condensing furnace was bought used. Who in their right mind sells a condensing furnace (used) in a probable high humid climate?

One that tried to install said furnace and couldn't get it to work. I have an innate ability to read between the lines. I've seen quite a bit of 'Tom Foolery' in my nearly 26 years of doing this for a living. We can't get it to work so we'll take it out and sell it to someone else.

So what makes the condensate drain system of a condensing furnace adequate?

The right way. What is the right way? The opposite of wrong.

If you want to learn how to do it: There are trade schools for that.

Class dismissed......

What does it look like? I have more of these images burned into my memory.... luckily for you I have a picture for you that you can actually see.

This one was fairly recent... so was this the condensing furnace this guy bought 'used'. Stranger things have happened. Right?

I service the Katy, Texas area.

I guess water is a by-product of combustion everywhere except in Katy, Texas.

I guess water is a by-product of combustion everywhere except in Katy, Texas.

They don't call them water furnaces do they?