Reusing Condensate

Rankin

I have a customer with a detached a garage and nicely installed Vitodens 100. Only problem is the condensate drain. There is no drainage in the garage, original installed put pipe through the wall for the drain, but with our cold climate, a two foot high mound of ice has accumulated below it, and last week, the drain froze.



She was considering hooking up a (large) tank for the condensate, holding it, and using it to pressure wash her floor every once in a while. Obviously, this water will need to be neutralized, but are there any other hazards I'm overlooking? Are there other serious contaminants in condensate? Has anyone ever had a sample tested?

I tried a search, but didn't come up with too much.



Any other ideas other than neutralizing it and dumping it?





Thanks,



Rankin

Tim McElwain

The first thing I

would do is contact local inspectors to see what you are allowed to do.



If the condensate is properly neutralized and a condensate pump provided then a storage container would have to be awfully big to hold all that until someone needs to use it. Example a 100,000 BTU boiler if it is running full for an hour will produce approx 1 gallon per hour

TonyS

Condensate pump

can you pump it  to a drain somewhere? If she collects the condensate she can use it to clean the floors without neutralizing, it is only a number 4 acid, many wells are that acid.

If she collects the condensate in a warm room it will go neutral all by itself in a day or two..just like soda goes flat. The acidity is just co2 dissolved in the water. You can also pipe it outside to a rain conductor but first you must remove the duckbill check from the condensate pump and pipe it in a drainback configuration.

Mike Kusiak_2

Condensate contaminants

Tony, there seems to be a few more acidic components in condensate than just the CO2. Here is a quote from a Rheem technical bulletin regarding the chemical composition:



"High efficiency in gas water heating appliances is achieved when heat from the flue gas is extracted before venting it to the atmosphere. Although natural gas is relatively clean burning, the products of combustion typically include nitrogen oxides, sulfur oxides and hydrogen chloride, as well as the expected water vapor and carbon dioxide. The hydrogen chloride comes from the combustion of chlorides (salt dust), chlorinated solvents,

chlorofluorocarbons, and hypochlorite (bleach) vapors contained in the combustion air supply. Nitrogen oxides are a typical by-product of combustion air. Sulfur is present at very low concentrations as odorant compounds added to natural gas. Condensation of these products of combustion yields an acidic solution which contains concentrations

of nitric, nitrous, sulfuric, sulfurous and hydrochloric acids."

 

TonyS

So does the rain Mike

I read in the paper the other day that our city water here contained 32 carcinogens.

I still have a bucket catching condensate under my Navien, I test it with an electric ph tester once in a while and I have pieces of copper brass and iron in the bucket to see what happens, this is going on for almost 3 years now but I havent tried watering my wifes plants yet. Im going to try it on one of them and see what happens. Ill let you know.

Rankin

Outside isn't an option

As the garage is far from the house and we experience temps as far as -45'F, we can't go outside. The customer has a sump she pumps out every couple of days using a sump pump, but that's in the middle of the floor, piping to that isn't an option. The roads are pretty heavily salted here, and as a result, she is left with quite a build up on the floor, hence the floor washing idea. It would be in no way connected to potable system, there is no water at all in the garage. I still want to be sure this isn't a potential hazard to my client. I will check with an inspector, and maybe consult Viessmann to see if they have any objections. The plan is to supply a 115 Gallon tank to supply her pressure washer.



Has anyone been faced with a similar scenario?



Thanks for the input.

Tim McElwain

Rankin

Yes very definitely every condensing piece of equipment presents a problem with what to do with the condensate. I feel that the equipment manufacturers should take the ball with this and provide a neutralizer on every piece of equipment. No two jobs are ever the same and getting everyone on board as to what you are going to do with the condensate is an issue.

Mark Eatherton

Tony...

Make certain that you only use it on Coniferous (Pine trees) types of bushes, otherwise you may be replacing her plants.... :-)



ME

Gordan

Heaths, too...

Rhodies, azaleas, andromedas, hollies, etc. - all acid-loving plants.



With all that acid, no wonder the azaleas break out in some pretty psychedelic colors...

Henry

Condensate

Normal condensate has a ph of between 4.5 and 5, not anymore acidic than lemon juice. Some jurisdictions require treating it before disposal in the sanitary sewage system. For our larger installs, we use a plastic one gallon container filled with terrazzo chips with the overflow going into a drain. Compared to the neutralizing cartridges, this will never block nor need replacing oin our lifetime!



For a homeowner with no drains available, a 2 inch dia well can be drilled a few feet in the floor and filled with terrrazzo half way up. This might be acceptable to the local jurisdiction as it has been in several in Canada. It is a local code requirement and not a National code requirement as to what to do with the condensate.



I hope this helps



Henry

HDE

I don't agree

With the exception to cast iron drains, water treatment facilities desire the acidity even, as minuscule as the amount of PH and quantity of condensate, it assists in neutralizing the massive amounts of basics we as humans introduce to the drainage systems.

Tim McElwain

If that is the case

and I probably agree it may be so why do mechanical inspectors make such a big deal about where it gets dumped in its non-neutralized state? Perhaps they do not know???

Bob Bona_4

I agree

with you Tim. Neutralizing is the responsible thing to do.

kcopp

That was my....

thought. Maybe you could put in a small sump bucket or a 5 gal bucket w. marble chips and put some holes in the sides for  it to perk out under the slab.... If it is so far from the house what is it heating? and how does it get water?

HDE

Easy

That would be the boiler manufacturers fault. Show it as an accessory and pictured in the drain drawings, and the inspectors that work best following picture books similar to comic books, feel they are needed regardless of the drain composition or material.



A lesson from the warm air side, neutralizers have been mentioned in the installation manuals (briefly) for 25 years? Why are they so rarely inforced but are on boilers?

HDE

Easy

Duplicate

Mark Eatherton

Easy...

Can not tell you how many floor drains I've seen that had NO P trap (bottom rotted out) due to condensing furnasties. The fact that they didn't do their jobs (contractor and inspectors) isn't acceptable. It certainly doesn't make it right.



I also have a friend, who does a LOT of work in the mountains, with condensing boilers, and has seen numerous septic systems destroyed by the acidity of the condensate. (all plastic drains are OK, right??)



Personally, I avoid working on THAT end of the system as much as I can, but am rethinking my position as it pertains to all plastic drain systems. I remember Brad WHite mentioning embrittlement of plastic due to the pH of the condensate. Or maybe its a reaction with the carbons...



I just like doing the right thing. I sleep better at night knowing I did as good as I could do given the situation.



JMHO



ME

HDE

How come

lets see, we dump 20x the amounts of soap then condensate at a minimum, septic failure was something else i am sure.



But wait condensate neutralizer bodies are made of PVC so that can't be the problem right?

Mark Eatherton

The problem is...

that the plastic pipes lead to a concrete tank, and the tank fails.



Just sayin'...



ME

HDE

Just had to

a condensate pump holds about 1 quart. I took the contents which tested at a PH of 5.5. 3 drops of palmolive dish detergent raised it to 7.3.



Think about the basics versus boiler condensate ratios introduced to a septic tank. Numerous softeners in the US are discharged into septic tanks, right or wrong, that would have a bigger effect on causing a cement tank to spall. Not naturally neutralized condensate



IMO

TonyS

Urine runs about the same

PH as gas condensate. How have you guys been neutralizing that?

And NO i will not test that out on my wifes plants. My scientific curiosity has limits

Jean-David Beyer

Really?

I thought urine ran slightly basic, like a dilute solution of ammonium hydroxide. And I know the condensate from my Ultra-3 runs pH 3 according to my pH paper (not terribly accurate); could be pH 4 or a bit higher.

TonyS

4.5 to 8

depending on your health.

Rankin

A 40x30 detached garage

It has an Axiom system feeder to maintain system pressure. I appreciate all your help so far, we'll probably just set up a catch basin with a neutralizer, and pump it outside in intervals.



Thanks,

Rankin

A 40x30 detached garage

It has an Axiom system feeder to maintain system pressure. I appreciate all your help so far, we'll probably just set up a catch basin with a neutralizer, and pump it outside in intervals.



Thanks,

TonyS

Heres something different

This Empire 90% fireplace evaporates the condensate for humidity. Its approved so it must be safe. Maybe you could pipe it to a humidifier and use it that way?



http://www.empirecomfort.com/

Mike Kusiak_2

Condensing fireplace

Doesn't that fireplace defeat the whole purpose of condensing? All the latent heat obtained by condensing the water vapor is given back to evaporate the condensate, so there is zero net heat gain from condensing. I guess the only benefit is that you can vent with PVC pipe?

TonyS

It also eliminates

getting rid of the condensate Mike. Im sure that could be a pain sitting on the fireplace.

You usually have to expend some energy humidifying and im sure using the heat from the fireplace is cheaper than electric.