Another wack-a-mole project:
I've seen lotsa posts on plugged AC drains but didn't see anything on condensation dripping from the refrigerant line. The supply and return are wrapped with that adhesive black gooey insulation tape, and I've also taken a section of foam pipe insulation to fit over that, with only partial success. Steady drip drip right where it bends to go into the evaporator, down on the tranny tunnel and then to the passenger floorboard where it slowly builds up and then SURPRISE! we're sinking! I have previously spliced a T into the evap drain hose and rigged a large pvc end cap to collect the drips, with a hose connected and assorted tie wraps to hold everything in place, but that only sorta worked and looked awful. Anybody have a better idea?

Hi,

Yes, on the drain pan bottom you need this!
Go to google and use the words “Duck Bill” drain hoses! You will see what you need to put in there. It needs to be long enough to reach from the pan bottom and through the sheet metal tunnel over the transmission. A couple to three inches long is all.
I don’t remember how far the plenum is up off the carpet and if the vacuum bottle is under there.

The duck bill seals the end to keep moist air from coming up towards the cold evaporator.
The weight of the water puckers duck bill slightly and let’s it drip out.
The car came originally with one.


The next thing is to get the facts straight in your head that heat travel towards cold.
Moisture, is heated water that is in vapor form.
When Heat gets inside molecules they are now jumping around.
This is not a normal state for any object in the universe.
It takes energy to keep things hopping! The theory of absolute zero is where all motion stops!

Cold, in plain essence, sucks the heat towards it. When the heat is gone, what you have is a condensed vapor into a liquid.
The tricks to stop this is “isolating the cold from heat.”
You don’t want to use a material that is heat conductive.

That black gooey stuff is a mass like dried hamburger wrapped around the tubing. It will conduct cold to the outside that will be almost as cold as the refrigerant in the tubing.
You want to insulate it with a low conductive material containing a thin inert gas substance or a vacuum.
A vacuum would be the best thing that is not always practical, in life, so we compromise!
This will create a “dead air space” with a minimum conduction material.
The answer is “closed cell foam.” Neoprene just happens to have low conductivity and reasonably priced.
It also helps create a vapor barrier to keep moisture farther away from being able to get next to the tubing to lose its heat and make water droplets.

I surmise that you are using the wrong type of foam wrap to begin with.
You can not use pipe plumbing products as they do not deal with such low temperatures in their environment. Mostly it the reverse and the tighter use of the foam cells are not needed there.

Refrigeration’s main purpose is sort of the opposite of insulation and therefore must include SEPARATION and ISOLATION! They becomes the key buzz words here!
You can get better product from a local refrigeration supply houses.
It comes 2” wide in about ten foot rolls with peel and wrap adhesive. It’s made by Calgon or more brands and it is a lot neater than the cork impregnated gooey stuff.
If needed another material can be used as a vapor barrier to wrap lines with but this usually comes into play with freezer applications.

Air conditioning is considered a high to medium low temperature application. Heat pump systems are considered as being in both worlds!

You can get what I’m talking, if you think into the physical aspects of what you are up against.

Phil

Thanks for the great response and info machine man.
The car still has the drain line hose from the evap which has a duck bill (of sorts), and a plastic insert inside the drain hose with a 1/8 hole drilled in it - are you saying that should be upgraded?

Also - on the insulation - I'm looking at Nu-Calgon Foam-Tite Insulation Tape, sku 4219-12, about $10 for a 30 ft x 2" roll - is that the product?
Description from the web site:
Foam-Tite Insulation Foam Tape is formulated from the highest quality closed cell elastomeric thermal insulation material. It can be used on all sizes of tubing and pipes, including iron pipe, steel and copper, as well as tees, valves and fittings. It can be used on cold water pipes, chilled water and refrigerant lines to prevent sweating and condensation.
If so I'll get a roll and redo that soggy mess!

Yes Chris - it's on recirc most of the time. Also that spray foam would make a huge mess (at least if I tried using it).

Hi,

Yes, about the tape product. Couldn’t remember how long it was in the box but it was dark blue and white!
I don’t know if Nu- is Nutone or not, but Nutone made lots of products for the home building industry.

Calgon was a large soap producer and then that lead into a silver solder flux maker!
They invented a liquid soap that made long lasting bubbles to become a leak detector in refrigeration and so on!
They made solutions for problems that are long into the history books.
It is probably been sold around now a few times with some name changing due to mergers and acquisitions!
This was bane of my earlier career of being a Journeyman Machinist and later working within Research and Development Departments!
The real kick in the butt came with the loss of rights to anything patentable because it was on company time! Tooling and all fixtures, are an invention, as much as the products themselves!
Companies got gobble up, by who knows what countries, wanting product control of the best America had or has to offer today.

The post, we all read, made me believe you did not have a duck bill nipple in the drain pan.
The PVC piping idea had me envisioning an old screen saver program of the desktop era!
This also made remarks come forth about whether or not you use the recirculated air mode. The thoughts were a lot on incoming humidity and water control.

As far as the canned foam thing, well, I could have asked you, How you were planning on molding it, but I knew it would not take you long to rule that out! (:-)
As the Karate Master, did not say to Grasshopper, wisdom grows slowly!

From your description of the product it sounds like they have upgraded the material away from the neoprene!
I spent 14 years gaining wisdom in maintaining refrigeration units for a Plant Operations Dept.
Unknowingly, the Navy GI bill gave me My backup or second career to work with.
I later became a Stationary Engineer, of which, was a lot easier than learning all the facets of Machine Tool Metalworking!
I still liked making unique one of a kind prototypes! But, I got Wiser and wealthier by Walking Away!

My motto is, To keep your eyes focused on trying to see past the horizon and to listen to what is not said!

Phil

Last weekend I spent some quality time upside down with my head up under the dash and my back comfortably supported by the front seat cushion and door threshold (LOL). Thank God for headlamps. Removed all the black gooey stuff and cleaned the refrigerant lines between the evaporator and firewall with mineral spirits. After removing all that stuff I noticed the rubber grommet that seals the hole where the line exits the bottom of the evaporator is off center, old and squished, and that appears to be the main source of the dripping water as there is a space big enough to get the tip of my pinky finger in there. So I did my best to clean and seal the hole up and all around the grommet with some Permatex gasket maker/sealant and then put the insulation on the lines. But it's still dripping from the hole, and given the awkward situation there I'm not surprised my attempt to seal up the hole failed. Well the insulation install looks good at least.... Probably going to go back to a new and improved version of a PVC cap to collect the condensate tapped with a nipple and short length of tubing teed into the evap drain line.

It’s starting to sound like the condensation drain tube is clogged. Have you pulled it out to see if it’s plugged up with yucky stuff?
--
Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)

Chris - yes that's been checked, removed, cleaned out and reinstalled (correctly and fully seated in the tranny tunnel). It's a very small amount now since the repair, but I still want to prevent that water from making it's way down under the floor mat. Got a few other ideas rattling around my noodle and will distill those before moving fwd.

Hi again,

Glad to hear that you are having better results with the line not dripping and the duck bill in the bottom is now draining.

Sorry to hear about the offset air gap. I gather the grommet has given up to be a ghost of past!

The off center is surprising but then again not so much.
Have you ever used Duct Sealing compound? It’s much like modeling clay and it’s not sticky, per say? That other stuff you used probably sagged away before it setup from its own weight.

You roll this stuff back and forth between your hands and make it look like a hot dog. Work it where you need it.
It comes in a one pound gob inside a plastic wrapper.
You can get it at a hardware as it is sold by, if I remember correctly, Gardner Bender Electrical.
I found it.
Edit: https://gardnerbender.com/en/p/DS-130/Duct-Seal-Compound-1-lb-Pugs
I have seen in Ace hardware stores for about $3.00 I think? Many places can carry it.
The stuff lasts nearly forever but it has other uses you will find out!

Especially, if you keep in an air tight jar. Be careful to not get it confused with the jar in the Beatle song. The Face she kept in a jar by the door. (-:)

This stuff doesn’t look like cosmetic makeup!
It’s dark gray but it forms up well and it does not conduct the cold very well, so it does not sweat.

This sealing effort should reroute any dribbles back into the housing, if you stop the air flow!
The blower creates a positive pressure inside the plenum and is blowing condensation towards the hole and outwards onto the line.
Put as much as needed, on the housings inside too! Even make an inner lip form inwards.
You want to stop AIR flow, but minimize a lengthy contact patch surface on the tailpipe from the evaporator.
The other insulation tape works well up against the duct seal or embedded slightly.

Hope this helps! It’s going to be one hot summer!

Phil

I wonder how that expanding spray foam insulation would work. It comes in different formulas that have different percentages of expansion. I’m guessing that the higher percentage of expansion, the more dead air space there is in the closed cells????

Also, you running the A/C on Recirc or are you continually drawing in moist outside air?
--
Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)