Stainless Water Storage Tank

[JonnieB]

This is a rather minor but nonetheless annoying problem. My stainless steel aboveground water storage tank leaks out water. Basically, evaporating water condenses on the underside of the lid. These water droplets then combine and then roll down the sides of the inside of the lid and out of the tank. They run down the sides of the tank and leave unsightly water trails on the tank and quite a bit of stagnant water under the tank area. Not only is this a waste of water but it is unsightly. Any suggestions on how to stop this?

[Jai Dee]

A continuous circumferential silicone bead on the inside of the lid (inside the tank lip) should cause the condensation to drip off the silicone and back into your tank.

[elkangorito]

You could also try drilling a hole in the top of the tank & attaching a 'breather' pipe into it. The outside end of the breather pipe will ideally end up pointing down & should be filled with something that allows the passage of air as well as blocking the passage of insects.

[JonnieB]

Interesting ideas...I think I will go for the silicone bead - maybe two beads so any water that gets past the 1st would be re-caught by the 2nd. With the second idea, don't I just end up with the same problem, a puddle of water on the floor outside the tank?

Funny this proboem, I have two tanks (different houses but same orientation to the sun) and one "sweats" like a pig and the other...nada?? The only difference is one is mor fat/squt in shape (leaker) and the other is tall/slim style.

[tjo o tjim]

With the second idea, don't I just end up with the same problem, a puddle of water on the floor outside the tank?

The "breather" pipe is just to allow air movement, which will allow some of the water to escape as vapor, but not as much as leaving the lid off.

Funny this proboem, I have two tanks (different houses but same orientation to the sun) and one "sweats" like a pig and the other...nada?? The only difference is one is mor fat/squt in shape (leaker) and the other is tall/slim style.

The increased diameter gives more surface area for water to evaporate, so the problem would be more pronounced.

[JonnieB]

With the second idea, don't I just end up with the same problem, a puddle of water on the floor outside the tank?

The "breather" pipe is just to allow air movement, which will allow some of the water to escape as vapor, but not as much as leaving the lid off.

Funny this proboem, I have two tanks (different houses but same orientation to the sun) and one "sweats" like a pig and the other...nada?? The only difference is one is mor fat/squt in shape (leaker) and the other is tall/slim style.

The increased diameter gives more surface area for water to evaporate, so the problem would be more pronounced.

Seems logical to me...I knew there must be someone here who didnt' sleep through high-school physics Applied the silicone bead today...will see how well it works. Not much of a sweating problem the past few days as has been overcast and not too hor most of the day in Pattaya recently.

[technocracy]

I've never actually understood what people go for the stainless tanks over the plastic lined version. When I was looking at them last year it seem a complete no brainer for the plastic not only are they cheaper but they have nearly three times the warranty of the stainless one.

Also for me they look far better and they don't have condensation issues such as this. Not that it is much help to the OP but it was something I pondered last year when on the market for a water storage tank.

[stevejones123]

In Lanka the alternatives are concrete or PVC. I can't understand why anybody would go for stainless steel.

[chownah]

With the second idea, don't I just end up with the same problem, a puddle of water on the floor outside the tank?

The "breather" pipe is just to allow air movement, which will allow some of the water to escape as vapor, but not as much as leaving the lid off.

Funny this proboem, I have two tanks (different houses but same orientation to the sun) and one "sweats" like a pig and the other...nada?? The only difference is one is mor fat/squt in shape (leaker) and the other is tall/slim style.

The increased diameter gives more surface area for water to evaporate, so the problem would be more pronounced.

Seems logical to me...I knew there must be someone here who didnt' sleep through high-school physics Applied the silicone bead today...will see how well it works. Not much of a sweating problem the past few days as has been overcast and not too hor most of the day in Pattaya recently.

Actually, for the sake of starting an arguement, I will disagree a bit with the "more surface area for water to evaporate" theory. Given that there is no ventilation of the tank and that the vapor pressure is the same regardless of the area of the surface of the water, then the concentration of water vapor in the atmosphere in the tank will be the same regardless of the area of the surface of the water. The key lies in the amount of surface are causing the condensation...the lid. The bigger the lid the more condensation you will have and the short squat tank has a bigger lid than the tall slender one....so the short squat big lidded tank will have more condensation.

I'm all pumped up and ready to argue so...over to you all!!!

Chownah

[jonniebkk]

With the second idea, don't I just end up with the same problem, a puddle of water on the floor outside the tank?

The "breather" pipe is just to allow air movement, which will allow some of the water to escape as vapor, but not as much as leaving the lid off.

Funny this proboem, I have two tanks (different houses but same orientation to the sun) and one "sweats" like a pig and the other...nada?? The only difference is one is mor fat/squt in shape (leaker) and the other is tall/slim style.

The increased diameter gives more surface area for water to evaporate, so the problem would be more pronounced.

Seems logical to me...I knew there must be someone here who didnt' sleep through high-school physics Applied the silicone bead today...will see how well it works. Not much of a sweating problem the past few days as has been overcast and not too hor most of the day in Pattaya recently.

Actually, for the sake of starting an arguement, I will disagree a bit with the "more surface area for water to evaporate" theory. Given that there is no ventilation of the tank and that the vapor pressure is the same regardless of the area of the surface of the water, then the concentration of water vapor in the atmosphere in the tank will be the same regardless of the area of the surface of the water. The key lies in the amount of surface are causing the condensation...the lid. The bigger the lid the more condensation you will have and the short squat tank has a bigger lid than the tall slender one....so the short squat big lidded tank will have more condensation.

I'm all pumped up and ready to argue so...over to you all!!!

Chownah

Tjo and Chow...I'll let you engineers slug it out...your theory sounds sound to me too...shows how much I know.

The SS tank in my house came with...maybe one reason people seem to prefer them to the plastic composites is they are lighter than the plastic tanks and easier to move around. Also, though I have never had to buy one, I have compared prices at the home centers and seems I remember just the opposite with regards to price...the SS are generally cheaper. (Otherwise surely they would not be so widely used.) Also, of all the houses (4) I have rented or owned, never had much problems with these SS tanks (except the sweating of this one tank).

Edited August 29, 2007 by jonniebkk

[elkangorito]

By putting silicon beading around the tank, you may in fact impede the ability for water to escape the tank i.e. if you suck water out of the tank & air can't get in to replace the area of the removed liquid, you will create a negative pressure in the tank OR your water pressure will reduce.

The reason why condensation forms on surfaces (like the ones we speak of) is because of the temperature of the Water vapour & the temperature of the tank material. My guess is that the plastic tank experiences a slower change in temperature than that of a metal tank AND plastic is a reasonably good thermal insulator whereas metal is a good thermal conductor. When the the outside of the tank cools quickly (unlike a plastic tank), the water vapour will condense onto the cooler surface. The surface of the plastic tank, being a poor thermal conductor, will not be as cool as a metal tank under the same conditions.

The only way to reduce internal tank condensation is to reduce the amount of water vapour in the tank. The only way this can be achieved without interfering with the operation of the water system is by the installation of a breather.

[chownah]

Elkangarito,

I think you have gotten the wrong impression about how the silicone bead is installed and works. It seems like you are thinking that the silicone is used to seal the lid to the sides of the tank. I think that the suggestion is to apply the silicone bead near where the lid meets the sides of the tanks but a few milimetres away from this juncture inside the tank. This way the silicone will not seal the tank but will form a drip cap.....a drip cap functions by forcing the condensation droplets to flow down to the lowest point on the bead where it will accumulate and fall off back into the tank because it can not move up along the outboard edge of the silicone seal since water doesn't flow uphill. A properly designed lid for a water tank should be built with a drip cap "wrinkle" stamped in (if it is a stamped metal lid) or attached (if it is a constructed lid) specifically for this purpose.

Chownah

[elkangorito]

Elkangarito,

I think you have gotten the wrong impression about how the silicone bead is installed and works. It seems like you are thinking that the silicone is used to seal the lid to the sides of the tank. I think that the suggestion is to apply the silicone bead near where the lid meets the sides of the tanks but a few milimetres away from this juncture inside the tank. This way the silicone will not seal the tank but will form a drip cap.....a drip cap functions by forcing the condensation droplets to flow down to the lowest point on the bead where it will accumulate and fall off back into the tank because it can not move up along the outboard edge of the silicone seal since water doesn't flow uphill. A properly designed lid for a water tank should be built with a drip cap "wrinkle" stamped in (if it is a stamped metal lid) or attached (if it is a constructed lid) specifically for this purpose.

Chownah

Thanks chownah