Drain for Furnace opinions needed

[Motofixxer]

I have a 95% High efficiency furnace in my shop. The problem I haven't figured out yet is how to run the drain hose. So my thought was just drill a hole through the exterior wall and run 3/4" pvc outside, and stick the drain hose in there. But my caution has been would that water draining end up freezing on the outside, and actually freeze closed? Therefore cutting off my drain. So anyone have any experience or input?

 

[240sxguy]

Do you have A/C out there? I can't imagine why you would end up with condensation during the winter time. Maybe a pipe leading outside during the summer and a bucket on the floor during winter?

 

[Jackfre]

Given that it is a condensing furnace you will likely make a boatload of condensate, and yes, it will freeze. You can get a condensate pump and pump it to the standpipe for your washing machine. Be careful where you dispose of it though. It is acidic and will deteriorate a lot of things, like concrete, metal piping, mild steel.

Years ago I had a customer who used his new hi eff furnace as a construction heater. He put no ducting on it and let the condensate run out onto the new concrete floor. He called me in the spring and told me he needed a new furnace. I visited and found the upright furnace suspended from some plumbers tape. The bottom 3" of the furnace were gone. As well, in about an 8' radius, the new concrete slab was about 2-2.5" thick rather than its original 4". There was some nice shiney aggregate there. He was angry at me. No new furnace!

 

[Motofixxer]

I have a regular house furnace in my shop, no A/C in it. The condensate drain is standard for that type of furnace. I got it for $100, how could I say no.

There are no drains I could run it into. I have been using a 5 gal bucket so far, but I'm trying to find a permanent solution. It does produce a lot more condensation than I thought they did. But it's also good to know it's acidic.

There must be a way it could drain outside and not freeze up.

 

[rlitman]

There must be a way it could drain outside and not freeze up.

Sure, just plumb the drain underground, below the frost line.
There is a drain kit for high efficiency furnaces that allows the condensate to pass over marble chips first, which reduces the acidity a lot.

 

[Highbeam]

I am forced to install a roof downspout collection system for the gutters on my shop. I put a knockout in the slab for a 2 inch drain line which will be connected to this stormwater disposal pipe. Underground won't freeze. The condensate water will be dumped into the storm system.

In your case, I would run the condensate water down into the slab and then underground outside to a drywell (big hole filled with gravel) If you can't cut into the slab for this then poke it outside and then down but be prepared to use a heat tape on the exposed pipe to prevent freezing.

 

[nmk_61802]

A little late now, but this is why my HVAC guy suggest no higher than 80% for shops and garages. Condensate goes out the flue, and you can shut it down in winter without fear of freeze ups.

 

[240sxguy]

Ahh sorry, I had no idea that type of furnace churned out condensate. Interesting topic. How much water are you generating?

 

[Motofixxer]

Yea, but for $100 I will use a stupid bucket if need be.

I normally keep it set way low between 35-40. So at that temp it's probably 2 weeks or so for 5 gallons. Up at normal 60ish temps probably 2-3 days for 5 gallons.

 

[jlckmj]

I had one in my shop until I took it out and exchanged it with my house furnace for those very reasons.

What I did to drain the condensate trap was drill a hole in the concrete floor and stick the drain tube down under the slab. There was enough gravel under there for it to dissipate. I doubt you will want to do that however because you just built that nice shop with that new floor.

ALSO, to keep the trap from freezing up when I shut the furnace down with the temperature below freezing, I built a small box out of plywood covered with Styrofoam and set a 30 watt light bulb inside the box to keep the water trap on the side of the furnace from freezing. I have had to do that for years with my well pump because it is located in the now unused milk house in the barn.

NOT a great fix, but it did work, and it was better than working in the cold when the furnace would refuse to light because it was frozen.

Jim

 

[HoosierBuddy]

Ahh sorry, I had no idea that type of furnace churned out condensate. Interesting topic. How much water are you generating?

I'm buying an Modine Effinity 93 for work. At 155,000 BTU input it is rated at 1.1 Gallon per Hour condensate.

A 5 gallon bucket won't last long.

Phil

 

[Mmfh]

Might not work for you but when the furnace was installed here, 96%, they ran the condensate line up into the attic, out through a soffit and dump into a gutter outside.

After reading that the water it produces is acidic, it might do a number on my new gutters?

That's the way it was done.

Mm

 

[Frank The Plumber]

I use a sealed unit that pulls cold air from outside for combustion air.

I wrapped mine with a heat wire, a decent one with a thermostat. I put the heat wrap on the same outlet as the furnace and used a switch so that they are only on together. Flip the switch and all is on. I used galvanized pipe 1/2" as the drop of 8 feet internally and a piece of 1 1/2" as the through wall ******. The heat tape is not good on PVC, The ****** is pitched hard to outside. The wrap stops at the wall. I have not had any troubles using this in 3 years in Chicago. The pipe stays warm enough for the water to drain out the wall at a high enough temperature. The unit does not start to generate a lot of water right away, by the time it does the pipe is warmed.

The water is acidic it has carbonic acid in it, mine is about a PH of 5 which is not horrifying. I tested it.

 

[TurnipTruck]

Sister-in-law's house just froze up and popped the baseboard copper in 9 places due to a dead mouse clogging the condensate drain, causing the condensate to back up and flood the boiler and shut down. In -27 F weather.

 

[softballrz]

if it is a short run the water won't freeze as it is warm coming from the heater. I run mine into the sump pump out to the rain gutter and it keeps the rain gutter from freezing. verify you will have no standing water in the line.

 

[Identaltech]

I just ran flexiable hose to a copper tee then thru the wall with a 90 outside. In the event it froze up outside it could still drain inside the garage thru the tee.
Been that way for years and never had it freze.
I first year I had heat I dumped it in a bucket but got tired for dumping it every other day.

 

[BillK]

Moto,
When we first installed the 90% furnace in my house we had problems the first year with the drain freezing and shutting the furnace off because the condensate pump would fill up When the the HVAC company installed it, they used a flexible plastic tube, probably 1/2" id to run it all the way outside. The tube was so small that it would start to freeze at the very end and then freeze solid.

What I did to fix it was put a 3/4" pvc pipe through the wall with a 90 bent up on the inside. I have the plastic tube from the furnace going into the pvc and then it drains outside. Since I did that I have not had any issues with it freezeng. It probably gets colder where you are though, so who knows ?

Mine goes utside then under my gravel driveway to a dry well. I didnt want it draining near the house due to the acidic problems that others have mentioned.

I will try to get a picture in the morning if you like.

 

[boo coo tracks]

I have a 95% High efficiency furnace in my shop. The problem I haven't figured out yet is how to run the drain hose. So my thought was just drill a hole through the exterior wall and run 3/4" pvc outside, and stick the drain hose in there. But my caution has been would that water draining end up freezing on the outside, and actually freeze closed? Therefore cutting off my drain. So anyone have any experience or input?

Drip will form icecycle (up to 10") & shut your furnace off. Don't ask me how I know!!!
Tracks

 

[chickenhauler]

Frank gave the same answer I thought of - heat tape on the line. I never thought to hook it up so it just worked with the furnace though.

 

[Motofixxer]

I like Franks idea with the heat tape, I had actually thought about that but wasn't sure if I would have to go to that extreme. Problem is though, can I get some short enough? I really only need to go through the wall. Is there really short lengths available, like 1'? I have only seen the pipe wrap tape, and the gutter stuff.

 

[mitymouse]

I build a stand pipe using 1" sch 40 pvc run it through the exterior wall and heat tape it, it doesnt hurt to make sure you check outside everynow and then to assure you are not creating an ice dam.
Also make sure you keep your building slightly above freezing (I belive I read you do) this will assure the furnace doesnt freeze up internally

 

[brad900]

Mine was only about a 3 ft line from furnace to outside & still froze up.They then tapped into the sewer line, good to go now

 

[Frank The Plumber]

I like Franks idea with the heat tape, I had actually thought about that but wasn't sure if I would have to go to that extreme. Problem is though, can I get some short enough? I really only need to go through the wall. Is there really short lengths available, like 1'? I have only seen the pipe wrap tape, and the gutter stuff.

The stuff I'm using is more like a cable with a thermostat, it came in different lengths. I used a good 3M temperature resistant black tape to fasten it to the pipe. It has a thermostat to keep from over heating. I put a few rounds of the tape every 6 inches to hold it nice. I had to tape the stat to the pipe so it could read the temperature. I think I found these cables at Menard's. I think it was between 20 to 30 bucks for it. I wanted a decent cable so as not to have troubles. 3 years so far. Still looks new. I did put it on the furnace switch to be certain my dummy me would not forget to unplug it, so now the only time the heat cable is on is if the furnace power switch is on. The only time the furnace switch is on I am usually in the shop, so I can see if trouble is happening too.

 

[diane.lisa69]

In physics, chemistry, engineering, and thermodynamics, heat is energy produced or transferred from one body, region, set of components, or thermodynamic system to another in any way other than as work.[1]

In ordinary language, as distinct from technical language, heat has a broader meaning.[2] This can lead to confusion if the diversity of usage of words is forgotten.[3][4][5][6]

Thermodynamically, energy can be produced or transferred as heat by thermal conduction[7], by thermal radiation,[8] by friction and viscosity,[9] and by chemical dissipation.[10][11]

The engineering discipline of heat transfer recognizes heat transfer by conduction, by convection, by mass transfer, and by radiation.

Heat transfer by conduction and by radiation from a hotter to a colder body is spontaneous. The second law of thermodynamics requires that the transfer of energy from one body to another with an equal or higher temperature can only occur with the aid of a heat pump by mechanical work, or by some other similar process in which entropy is increased in the universe in a manner that compensates for the decrease of entropy in the cooled body, due to the removal of the heat from it.[12] For example, energy may be removed against a temperature gradient by spontaneous evaporation of a liquid.

In physics, especially in calorimetry, and in meteorology, the concepts of latent heat and of sensible heat are used.

A related and potentially confusing term is thermal energy, loosely defined as the energy of a body that increases with its temperature. Potentially confusingly, thermal energy is sometimes referred to as heat, although the thermodynamic definition of heat requires it to be in transfer between two systems or in production in a dissipative process such as friction, viscosity, or chemical reaction.

 

[39portlander]

D&L 69, that's hillarious Use the heat tape (granger, ect.) We use the plug in heat tape all the time on condensate drains for walk-in freezers. And yes you got to wrap it with the foam tape after.

The condensate is about as acidic as pure premeium Orange Juice, fear not

 

[rburke65]

What he said!

 

[Motofixxer]

What he said is:

"The advantage of this type of heating is based on heat-producing systems of large size, have much higher returns than smaller ones, so that more fuel is used. The average yield is estimated to be 10% higher, at least to the centralized systems of building and between 30 and 40% higher than individual housing, which means a great saving of greenhouse gas emissions emissions. In addition, plant emissions are cleaner than those of other contaminants smaller boilers.

From a purely economic point of view is also favorable because, being the major consumer of power plant fuel, you can negotiate with suppliers low price of energy.

But the biggest advantage of these facilities is that as the heat source can be used other possibilities such as geothermal energy or waste heat from industry processes or cogeneration.

In these cases, the heat distribution is used to create cold for air conditioning by absorbing devices installed in the substation building, with a very favorable economic returns compared to generation by compression."

 

[39portlander]

Some one has wwway too much time on there hands

 

[Motofixxer]

I'm still not sure how any of it fits in to the conversation...but that's ok.

 

[Kev442]

I too learned really quickly how fast a 5 gallon pail will fill, so I have run a line all the way into the basement from the garage and it goes into the same drain as the house furnace. About 40'!

 

[trbomax]

I just ran mine thru the furnace room wall and then along the shop wall,where it dumps into my trench drain.Everything is inside that way,no wall pennetrations.

 

[TheManShopSD]

This is the setup I have in the shop. We just purchased the house with the shop. So far, I only run the furnace when I am in the shop. We have had a very mild winter here in SD. The shop is well insulated and has stayed around 32-36 degrees when I am not out there. You can see the ice cream bucket that catches the water. I have to dump it out at least once every time we are in the shop. That is not a big deal but it is a pain to clean up water every time my 5 year old is shooting hoops and hits the bucket away from the drain.

After reading this thread I am wondering what the best way to drain the water out of the shop would be. I am also wondering what is the point of having the pvc with the spigot on the side(shown in the photos). One thought is to cut a drain hole in the concrete and let the water drain under the slab as there is another floor drain that I pour water into at the other end of the shop. Can anyone explain the pvc drain setup on this furnace? Is there a reason why the small drain spigot is needed? Can I remove it and just let the water drain into a bigger bucket for now? Thanks.