Dehumidifier drain question

[Raymond Fries]

We had a dehumidifier installed in our indoor greenhouse along with a mini split last summer. They ran a drain line outside and into a french drain. They also put heat tape around the drain pipe and covered that with foam insulation. This past Sunday there was water on the floor and a service call was made. The technician who came believed that the problem was because water had frozen in the line. They want to come back and install a tee so that we can dump hot water in the drain pipe and clean the line with bleach. Really? I read nothing in the install instructions about a tee and cleaning the drain line.

We did have a power outage a week ago for about 6 hours when it was extremely cold. I am sure that any water in the line outside could have frozen. But wouldn't the heat tape have melted the water in a week?
The line coming out of the house extends about 6" then an elbow sends the pipe down into the French drain. The heat tape is wrapped to within 6" of the ground.

Q1. Are these tees common practice?
Q2. Shouldn't the heat tape have melted any water in the pipe?
Q3. Anyone else have a dehumidifier draining to the outside in cold weather with a different install solution?

I am afraid the contractor wants to take a shortcut with the tee and have me monitor a freezing pipe. I do not want to wait until water is running out of the bottom of the dehumidifier and then run to get hot water and take care of a frozen pipe.

Sorry for the long post but necessary to explain.

Any thoughts or suggestions is greatly appreciated.

[Jerome Stanek]

my question is why a dehumidifier in the winter. What are you growing in the greenhouse. We had one when I was younger and could not use a dehumidifier as it was over an 1 1/2 acres. This was in the Cleveland Oh area

[Mark Bolton]

It doesn't meet code in a lot of areas, and a lot of people are reluctant if they are on a septic, but the subs I've use often dump them into a sanitary drain. In cold climates the general practice is not to drain them outside due to what you experienced.

Do you not have a floor drain in the greenhouse you could somehow tie into?

[Mike Lassiter]

as I read and understand your post the drain has been ran outside exterior wall about 6" then elbowed down into the ground to tie into a french drain. The drain pipe has a heat tape and insulation on in from the wall to within 6" of the ground. If I am understanding correctly I would think the drain pipe froze between the ground and where the heat tape and insulation stopped. The drain likely gets a trickle of water down it that slowly froze in the unprotected area and as more water trickled down to that area from the protected part it too froze and gradually plugged the pipe which then backed up inside. You probably did still have unfrozen water in the heat taped and insulated part.
My thoughts are (based on my asumption of situtation) would be to dig down around the drain in the ground and go maybe a foot or whatever your frost depth is expected in your area. Get a good quality foam pipe insulation that is split with adhesive on the edges to place around the drain, get a longer heat tape that can go on the pipe into the ground and to the wall the pipe comes out off. Cut the drain pipe eblow out and install the heat tape and pipe insulation on the pipe then slide a 2" (this will work on 3/4" drain) pipe over the insulation into the ground so it will protect your insulation and long enough to extend out of the ground to below the elbow so you can glue it and possible short sections of pipe in if needed to reconnect pipe. Then finish running heat tape back to the wall and cover with the foam insulation sticking out of the 2" protective pipe. This is MUCH simpler to do than explain!
If the ground froze for several inches deep with uninsulated pipe a slow trickle of water would slowly freeze and continue to buildup inside tge pipe until it was blocked and in any unprotected area exposed above the ground. Heat tape and insulation ran to 6" above the ground left that 6" to freeze

[Myk Rian]

I don't understand having a dehumidifier in a green house, but whatever.
Run the drain line into a sprinkling can and use it to water the plants.

[Raymond Fries]

This is a four season greenhouse. It has 22 Anderson windows and 4 skykights. Before we had the dehumidifier installed, she used an exhasut fan to exit the humid air from the room. Without this, the windows would ice over and then the ice would melt and soak the wooden frames of the windows. This becase very costly as we were just sucking the heat out of the room. Our electric bill went up about $200 a month for a 14' x 16' room. Tne dehumidifier and mini split replaced a PTAC unit and running the exhaust fan. I made a shutter to close the opening for the exhaust fan.

There is no floor drain and this is why it was ran outside.

What Mike said is what I believe happened. When the heat tape was installed, I wondered why it was not run to below the ground level. There is plenty of extra tape inside. I think the guy filled the sleeve around the drain pipe with gravel before he ran the tape and that is why it stopped above ground. He said we would not have a problem and I did not want to challenge him. It makes sense that the water would slowly freeze in that 12" or so section of the pipe between where the heat tape stops and below ground level where there is no heat. I think I will discuss this with the contractor when they call back today.

It is still a mystery why it plugged on Sunday as it was 36 degrees outside. Maybe the water would still freeze running over the ice in the pipe on its way to the bottom of the drain.

Somehow it will get resolved. Thanks for your thoughts.

[Jerome Stanek]

Still can't understand a dehumidifier for a greenhouse. Ours was in use every day year round.

[Jim Koepke]

Still can't understand a dehumidifier for a greenhouse.

It gets like a tropical jungle in our greenhouse at times. Some plants do not like that high of humidity.

Sometimes it drips inside our greenhouse. If there is wood construction and glass windows there can be other problems.

I think the original install was done incorrectly. Sometimes it is difficult to get a contractor to make it right when they are trying to defend their having done it wrong.

jtk

[Raymond Fries]

The contractor called today and we discussed the problem. Does anyone know if heat tape can get wet? I assume it is rubberized and will be just fine to go below the ground with the drain pipe. The contractor hesitated and said he thought there might be electrical issue with it and he was not sure. He said a tee might be a better solution but he would do whatever I wanted. I just do not want to setup a schedule to dump water into a drain line to keep it from freezing unless there is no other option.

Does anyone one see an issue with the heat tape getting wet because of being in the ground? I thought Mike's solution sounded good. Does anyone disagree with this? I do not want to do the wrong thing here.

Thanks

[Jim Koepke]

Does anyone one see an issue with the heat tape getting wet because of being in the ground?

If it is outside, what is going to keep it from getting wet when it rains?

Is it possible to install a plastic drain pipe around the current drain to keep water away?

jtk

[Myk Rian]

Does anyone know if heat tape can get wet?

Sure it can. I have it in my gutters, and running through the downspouts.

[Mike Lassiter]

The contractor called today and we discussed the problem. Does anyone know if heat tape can get wet? I assume it is rubberized and will be just fine to go below the ground with the drain pipe. The contractor hesitated and said he thought there might be electrical issue with it and he was not sure. He said a tee might be a better solution but he would do whatever I wanted. I just do not want to setup a schedule to dump water into a drain line to keep it from freezing unless there is no other option.

Does anyone one see an issue with the heat tape getting wet because of being in the ground? I thought Mike's solution sounded good. Does anyone disagree with this? I do not want to do the wrong thing here.

Thanks

Raymond the heat tape is sealed but probably not intended to be fully submerged all the time. The 2" pipe I remarked about is how I have the main water lines to 2 mobile homes coming out of the ground that supply water to them. Both have foam insulation surrounding the 3/4" main and then the 2" pipe over that to protect the insulation that comes up out of the ground several inches. One mobile home has heat tape which I just added a couple of weeks ago during the single digit weather we had. I was able to split the foam insulation back apart at the seam and slip the heat tape down into the 2" pipe going down in the ground as far as I could then close the foam back up over the pipe and heat tape. I didn't have heat tape on it (either one - the other one has brick around it, this one nothing due to major work being done) but hadn't had problems with the water freezing even down into the teens here for a few night but the water was left running a fast drip in the bathtub. The problem was (just exactly the same one your are having) the drain pipe froze and the water was backing up in the drain pipe. I had to turn the water off to keep from creating problems with the frozen drain - then the water line froze. Heat tape fixed that.

I don't really understand the reluctance about the contractor doing it, and especially why he's concerned about it getting wet. It would be no more able to get wet extending it down the 6" or so you said it ended above ground now and running it down to the ground then below grade (with the pipe protecting it from weed eater or accidentally hitting it with a hoe or shovel if in flower bed area working the dirt) than it already is. It is exposed outside now as much as I propose other than being a few inches more of it. The one I just installed said in instructions not to bury it into the ground - so even though I did extend it below grade of the ground it is not buried "in the ground" - in that it is not in direct contact with the dirt.

Reading another post you made I think you have indicated the heat tape is long enough that you already have installed to do what needs to be done - but wasn't done so the drain would have uninterrupted freeze protection. Don't know if the pipe was insulated down into the ground but it should be and the heat tape inside the insulation to a depth that the ground will not freeze the water if you have an extended cool spell where the ground freezes several inches (feet). The water draining inside the pipe don't care if the cold outside air freezes it, or the frozen ground does - it will still block the pipe.

on edit:
The heat tape must be installed on the BOTTOM of the horizontally ran pipe and it needs to be placed on the vertical pipe so it will continue down the vertical pipe straight down from the elbow so the water that trickles down the pipe will have the heat tape to keep it from freezing. Basically run it on the bottom of the pipe exiting the wall and bent down with the elbow so the heat tape is still against the pipe and not off to the side or the side opposite the elbow. Water will dripple down the elbow and continue down the pipe wall straight down. That's where the heat tape needs to be placed.

[Raymond Fries]

Thought I would post some pictures of what they did to help you see.
Drain1.jpgDrain2.jpgDrain3.jpg


Interesting that the sleeve is full of water and ice down to thew level of the gravel in the sleeve as you can see in the last picture. GUess that answeres the question of it getting wet. HUH.
Looks like they wrapped the tape instead of running it along the bottom of the PVC pipe as Mike suggested; what he said seems to be a better solution. Not sure if this matters. I think the sleeve runs down about two feet. Any idea how deep the frost line is? Surely if they run the heat tape to the bottom of the hole, it should not freeze.

Thanks all for your comments.

I like MIke's solution. If they lose the gravel and replace it with a foam wrapped drain line with heat tape along with a union, it would be easy to change the tape someday when it quits working. Do you think the line coming out of the house coul;d be pressed into the elbow and not use PVC solvent to weld it together? This would make for a smaller connection and not require a union.

[Mike Lassiter]

Raymond they have already done basically what I have been saying!

I see several things IMO that aren't right. First they DID use a larger pipe to protect the drain, but look at the difference between the insulation and the pipe - there's a lot of gap there for cold air to get in and freeze the drain up. This all makes sense now - in a way. As I said they did what I would have done expect I would have started in the ground and worked back to the wall, so the foam insulation and heat tape would have been down inside the bigger pipe and protected the drain inside if from freezing. I submit they did the outside work with the pipe inside the pipe then tied the drain from the outside wall into that with the pipe inside having no heat tape nor insulation. They couldn't run the heat tape down into the bigger pipe nor the insulation with the bigger pipe already set in the ground around the drain.

MAYBE possible to cut the plastic wire ties ( poor choice IMO, I would have used the foam that has adhesive on the slit to seal it together, or wrapped the foam with a good quality duct tape to hold the foam closely together. IMO even though it has insulation over it, it has gaps open that allow cold in - and rain too; and he was worried about the heat tape getting wet?) pull the foam off around the pipe and take another piece of foam insulation and slip over the drain pipe and try to slide it down inside the larger pipe while letting it wrap around the drain pipe. Run that down at least a foot below ground (more if you live in very cold climate and ground will freeze deeper) let the split opening go under the elbow so that the part of it all as we see in the picture has the solid foam facing you. Probably need to miter a section out so the foam can be bent over the elbow and back over the horizontal ran pipe with the split in the foam facing down toward the ground. Wrap that with duct tape. If there is still the gap between the larger protection pipe and foam insulation, it needs to be closed up. Maybe use fiberglass pipe wrap and wrap the top of the larger pipe and go back over the elbow and horizontal pipe too. Duct tape wrap this going down over the PVC so you have sort of sealed it all with duct tape to keep water out and protect the insulation. I don't think I would dig the PVC up to do what I originally described. This is almost there, but that large opening between the foam insulation and the PVC is letting cold air get in where the insulation and heat tape is not at.

[Mike Lassiter]

I cannot tell by looking at your pictures but does the smaller pipe that is wrapped actually go down inside the larger PVC pipe and connect to the drain below grade, or is the PVC the pipe connected and the smaller one ends just at the top the larger pipe? It might be they wrapped the drain coming out of the wall and put the heat tape on it, but the PVC pipe you say is full of water perhaps is what is tied into the in ground French drain and it froze. If it froze and the elbow extends down just a little into the larger PVC pipe the larger pipe maybe the problem - freezing and then freezing up to the drain that has the heat tape wrapped around it.

If that is the case, I guess I can see why the contractor is reluctant to do what I said - because the smaller pipe doesn't actually go all the way to the drain in the ground.
Does that make sense (I understand perfectly clear )?

I guess after posting this it occurred to me the larger pipe being full of water either indicates it doesn't actually go down into another drain pipe with the smaller pipe (if that's now it was done) or is blocked. Consider if they have gravel around that pipe and it is in fact open to the ground at the bottom. The drain water would run into it from the smaller pipe and just soak into the ground, or possibly overflow it but it wouldn't prevent the smaller drain pipe from letting water out - unless the larger pipe freezes and it continues freezing until the water has risen enough that it has gotten to the smaller pipe and froze at the end of it. The pipe has heat tape ON IT, but that wouldn't prevent water from freezing at the opening and blocking it.