Condensation on aluminium window frames

[elessina]

Any ideas / tips on how to reduce / eliminate condensation on aluminium window frames?

 

As soon as the outside temperature falls to below around 5 degrees we get a lot of condensation on our gold anodised aluminium window frames. I thought having a 'dry' interior may help, but last night kept the de-humidifier going and the inside humidity was kept to around 40%, but I could not see any difference compared to normal when the inside humidity is around 50%.

 

We left the curtains open on one side of boat and closed the other side. No difference!.

 

Ian

Elessina

[bottle]

Any ideas / tips on how to reduce / eliminate condensation on aluminium window frames

?

 

Yes ................................replace them with wood, even that will not totally stop it.

 

Joking aside, it is not possible to remove all the condensation, as you know condensation is the condensing of water vapour on a surface that is colder than the surrounding air, the only way to stop it on the aluminium is for the aluminium to be 'warm'.

[tomsk]

?

 

Yes ................................replace them with wood, even that will not totally stop it.

 

Joking aside, it is not possible to remove all the condensation, as you know condensation is the condensing of water vapour on a surface that is colder than the surrounding air, the only way to stop it on the aluminium is for the aluminium to be 'warm'.

 

Thats it really

[monty]

Thats it really

Try rubbing some neat washing up liquid on them or you could put cling film over them which can help

[blackrose]

The same thing happens on my aluminium portholes. I ditched the curtain idea and experimented with 1" thick medium density foam discs which fit into the wooden trim recesses. (I know the boss of a foam fabrication company.) Great insulation - I can see the difference they make on the outside of the boat where the windows used to transfer heat onto the metal superstructure and melt off the dew or ice. It also stopped the condensation too for a while, but because of the warmth on one side and cold on the other, the foam expanded slightly on the inside and contracted on the outside causing them to become convex and fall out.

 

I will eventually stick them to some single sided oak-faced ply discs which will be hinged at the top of the porthole recess, with a small hook at the bottom of each disc and an eye on the ceiling - like shutters for the inside.

Edited December 18, 2006 by blackrose

[Linty]

The same thing happens on my aluminium portholes. I ditched the curtain idea and experimented with 1" thick medium density foam discs which fit into the wooden trim recesses. (I know the boss of a foam fabrication company.) Great insulation - I can see the difference they make on the outside of the boat where the windows used to transfer heat onto the metal superstructure and melt off the dew or ice. It also stopped the condensation too for a while, but because of the warmth on one side and cold on the other, the foam expanded slightly on the inside and contracted on the outside causing them to become convex and fall out.

 

I will eventually stick them to some single sided oak-faced ply discs which will be hinged at the top of the porthole recess, with a small hook at the bottom of each disc and an eye on the ceiling - like shutters for the inside.

 

Thanks for that last !!! We're at the stage of furnishings/curtains/etc on our boat, and I was going to make porthole bungs. I shall adapt your idea - no patent pending I hope !!!

[elessina]

Thanks Monty and Blackrose,

 

I Tried the Fairy liquid last night, it certainly helps. I tried clingfilm a few weeks back, but without success.

 

Will make up some ply / insulated cutouts for portholes. It has also made me think that making some cutouts in clear acrylic plastic may also work, if a good seal can be made around the porthole linings, which should be possible.

 

Ian

Elessina

[blackrose]

Thanks for that last !!! We're at the stage of furnishings/curtains/etc on our boat, and I was going to make porthole bungs. I shall adapt your idea - no patent pending I hope !!!

 

Adapt away, but what will you do about your larger windows? Mine are all portholes so it's a bit easier.

 

I met Bill & Sue from Isambard last summer who kindly showed me around onboard. After telling Bill my idea for foam porthole bungs he said "Just be aware that the condensation has to go somewhere so you shouldn't block it completly."

 

I nodded my head, but as I was walking back to my boat I thought - Hang on, what's he talking about? Condensation will only form where warm air meets a cold surface. If the air has no access to the cold surface there will be no condensation. Therefore it doesn't have to go anywhere because it doesn't exist!

Edited December 20, 2006 by blackrose

[elessina]

Adapt away, but what will you do about your larger windows? Mine are all portholes so it's a bit easier.

 

I met Bill & Sue from Isambard last summer who kindly showed me around onboard. After telling Bill my idea for foam porthole bungs he said "Just be aware that the condensation has to go somewhere so you shouldn't block it completly."

 

I nodded my head, but as I was walking back to my boat I thought - Hang on, what's he talking about? Condensation will only form where warm air meets a cold surface. If the air has no access to the cold surface there will be no condensation. Therefore it doesn't have to go anywhere because it doesn't exist!

 

For the larger windows, Fairy liquid seems best bet to date!!

 

We too met up with Bill and Sue. RE. condensation has to go somewhere, I have heard this before, and that it will go to the next coldest surface, but not experienced it..... eliminate all cold surfaces and you will have no condensation!!... but easier said than done on a steel boat!!.

Ian

[Linty]

Adapt away, but what will you do about your larger windows? Mine are all portholes so it's a bit easier.

 

To be honest, I don't know - will try the washing up liquid idea, I have heard of that one before.

 

Longterm I think the solution probably would be wooden window frames - which I did see on a boat on the Macclesfield Canal last year, since no condensation forms on the wood anywhere in the boat. BUT since our boat is new, then we will have to live with wiping down for some considerable time! coupled with adequate ventilation

 

Might try those dessicant strips also, if I can find them. I doubt that will stop the condensation, but it will soak it up.

 

Linty

[minerva]

I once got some of that plastic secondary double glazing, you used to be able to buy... you put like a double sided sticky tape round the frame, on the wood edging, then there are big sheets of thickish plastic you cut out to the size of the window frame, then make sure it is stuck on to the double sided sticky tape all the way round the window, then you use an hair dryer to make it drum tight....the downside is obviously you cant open your windows till you remove it all in spring time, but it works.

 

p.s. i dont know if anyone still sells this though..

 

(diy's used to)

[elessina]

I once got some of that plastic secondary double glazing, you used to be able to buy... you put like a double sided sticky tape round the frame, on the wood edging, then there are big sheets of thickish plastic you cut out to the size of the window frame, then make sure it is stuck on to the double sided sticky tape all the way round the window, then you use an hair dryer to make it drum tight....the downside is obviously you cant open your windows till you remove it all in spring time, but it works.

 

p.s. i dont know if anyone still sells this though..

 

(diy's used to)

Thanks Minerva,

 

I did see some in our local B&Q a few weeks back, and was tempted to buy / try it. My main concern is that the double sided tape may damage the woodwork when removed (we have teak wood surrounds)….. did you have any problems / damage removing the tape after winter?

 

ian

[skeets]

we have used bungs at night, ours are insulated with wadding, the condensation is less on these portholes than the ones that have curtains, so much so that i am now going to make bungs for all the portholes.

[minerva]

Thanks Minerva,

 

I did see some in our local B&Q a few weeks back, and was tempted to buy / try it. My main concern is that the double sided tape may damage the woodwork when removed (we have teak wood surrounds)….. did you have any problems / damage removing the tape after winter?

 

ian

 

Erm I can't say that we did, having said that the wood wasn't teak!!

but if it leaves any sticky residue, surely that could be easily removed....?

 

~~~~not sure how though, without bringing the varnish off(may be)... hmmm....

 

Maybe some hot water and washing up liquid would bring it off nicely thinking about it......

[tomandsophie]

I've finally found a solution that looks nice! As said before, the reason that the condensation forms on the window frames is because they are metal and therefore cold. So I figured that the condensation couldn't form if the metal was covered with something that doesn't get so cold, like wood or material. I tried material and it worked but looked ridiculous! So I went to a DIY store yesterday and bought a 2m strip of pine that is exactly as wide as our window frames. I cut it to size and stuck it on with double-sided tape (will seal it properly when I have ascertained that it works!)so that all the metal is covered. This I did yesterday. Then I did masses of washing and hung it up around the boat (needed doing anyway ) so there would be loads of condensation by morning...

Got up this morning and lo and behold! No condensation! Of course the actual window is covered in it, but that I don't mind because it all drains into a little channel and goes outside, I guess all windows must have this facility. But as far as the frames go - not a drop. At last, no more condensation running down the walls off the frames and leaving 'orrible marks.

[ChrisPy]

I've finally found a solution that looks nice! As said before, the reason that the condensation forms on the window frames is because they are metal and therefore cold. So I figured that the condensation couldn't form if the metal was covered with something that doesn't get so cold, like wood or material. I tried material and it worked but looked ridiculous! So I went to a DIY store yesterday and bought a 2m strip of pine that is exactly as wide as our window frames. I cut it to size and stuck it on with double-sided tape (will seal it properly when I have ascertained that it works!)so that all the metal is covered. This I did yesterday. Then I did masses of washing and hung it up around the boat (needed doing anyway ) so there would be loads of condensation by morning...

Got up this morning and lo and behold! No condensation! Of course the actual window is covered in it, but that I don't mind because it all drains into a little channel and goes outside, I guess all windows must have this facility. But as far as the frames go - not a drop. At last, no more condensation running down the walls off the frames and leaving 'orrible marks.

hey guys, it seems you've put your finger on the problem - inadequate design by the window frame manufacturers. If there is a drain then it should drain off everything that collects on the exposed surfaces, not just what collects on the glass.

 

I'm away in Turkey again just now and can't inspect my frames, but am I right in thinking that, in the case of rectangular windows, the only part of the frame that collects condensation is the bottom section? If so it is only the bottom section that needs a permanent timber liner, which should also act as a gutter, directing water that has run down the sides into the bottom drain outlets. For portholes a similar scoop-shaped liner covering the bottom quadrant. Anybody fancy producing some in oak?

[elessina]

Inadequate design…. One day the window manufacturers will come up with a cold seal, like house aluminium windows used to have (a rubber 'break' between outer aluminium and inner)…. Either that or a boat window in UPVC…. The problem with UPVC is that the frame has to be wider for rigidity and it would not look right.

 

My original plan was to have the inner wood trims cover the visible aluminium frame, which would have the same effect as covering the frames with pine strips, but unfortunately our windows have a bracket on the sides to hold the top opening windows, which also eliminates the pine strip solution, although I could do this on the lower window frame, which is the biggest problem, as the lower (fixed) window have no self drain (We have arched top windows – Dutch Barge style).

 

My guess is the pine strips will only be a relatively short term solution, because they will rot (maybe last 3 years), hardwood may last a little longer. Plastic strips may be another solutions, I believe B&Q and the likes sell 2m long, 2mm thick plastic strips, possibly different widths and in white or black. For us, black ones may not look so bad. Maybe worth a try. I am a little loathed to try double sided tape on the window frames, for fear it may be difficult to remove later, if not successful. Some tapes when left a few months seem to go brittle which makes them very difficult to remove. I would be very tempted to use the pine strips with double sided tape if they could easily be removed at the end of winter.

 

I did try putting some black insulation tape around the window frames (insulation tape because it could be removed easily). It helped a little, but now removed!!. … Now there's a thought, insulation tape, then double sided tape then strip-wood, removed at and of winter.

Ian

[nickelodeus]

Hi Folks...

 

Yes! damn this condensation....I'm getting mould growing in the corners of my windows too - channelglaze ally ones....but that said, they do need refubishing anyways but that'll have to wait now until spring cos I don't fancy having a window sized void at this time of year! Its also ruining the wood sill surrounding the window frame

 

A friend of mine who also lives on a boat and has had several over the years tried the clear acrylic idea for his portholes and made them fit with rubber piping round the edges to make a seal. Short answer - he said it didn't work. So he now uses the foam bung solution and swears by it.

 

I'm not to fussed about my portholes cos they're only small, and there are only 4 of them - the main thing thats bugging me is the damn windows. The water seems to be dripping off the top inner edge of the frame and is actually missing the channel at the bottom altogether and landing on the wooden sill (surround) due to the angle of the cabin sides.

 

My 2 pennies worth!!

Nick

[magnetman]

The water seems to be dripping off the top inner edge of the frame and is actually missing the channel at the bottom altogether and landing on the wooden sill (surround) due to the angle of the cabin sides.

 

If you've got hopper top windows open them a tiny bit and put a wedge on the support bracket to hold them open at that point, then the condensation drips run down the outside of the top of the window. also a bit of fresh air might reduce the condensation anyway.

[tomandsophie]

our windows have a bracket on the sides to hold the top opening windows, which also eliminates the pine strip solution, although I could do this on the lower window frame, which is the biggest problem, as the lower (fixed) window have no self drain (We have arched top windows – Dutch Barge style).

 

My guess is the pine strips will only be a relatively short term solution, because they will rot (maybe last 3 years), hardwood may last a little longer.

Ian

 

Our windows also have that bracket at the top, so the pine strips I have cut only cover the bottom and the sides up to the top hopper. It is only these sections that cause the problem anyway.

 

The pine strips are only a short term solution - they were only intended as an experiment (I only did one window) to see if it would work. It only cost £2 to do one window. Now that I know it works, I will go back and buy some oak strips - double the price but that's still only £4 per window - and varnish them and stick them on with some decent silicon sealant.

[elessina]

.....tried the clear acrylic idea for his portholes and made them fit with rubber piping round the edges to make a seal. Short answer - he said it didn't work. So he now uses the foam bung solution and swears by it.

Thanks..... I will get some foam!!, saved me a few pound on acrylic sheet.

 

Our windows also have that bracket at the top, so the pine strips I have cut only cover the bottom and the sides up to the top hopper. It is only these sections that cause the problem anyway.

 

The pine strips are only a short term solution - they were only intended as an experiment (I only did one window) to see if it would work. It only cost £2 to do one window. Now that I know it works, I will go back and buy some oak strips - double the price but that's still only £4 per window - and varnish them and stick them on with some decent silicon sealant.

 

Sounds good, Thanks

 

Ian

[Alastair]

You are trying to hold the RH down to 40% in winter? That's awfully dry. The average RH in York often doesn't drop below 80% for weeks at a time.

 

"Condensation has to go somewhere"

 

There is an element of truth in this. I had to pay for an engineering analysis of a new house roof, and it was very interesting. The analysis was all about working out *where* the dew point (ie, 100% RH) is in the layers of the roof. Ideally, it should be in a layer that is vented, so that the condensate is evaporated when the temperature changes.

 

In insulating a boat, we should bear this in mind. We don't want the dew point to be on the steel, as that promotes rust. Ideally, we seal the steel surface - sprayfoam is the only guaranteed way of doing this, AFAIK.

 

If we can't seal the steel, then we need to give the condensation an escape route. Therefore it forming on your windows isn't necessarily a bad thing.

[blackrose]

"Condensation has to go somewhere"

 

There is an element of truth in this. I had to pay for an engineering analysis of a new house roof, and it was very interesting. The analysis was all about working out *where* the dew point (ie, 100% RH) is in the layers of the roof. Ideally, it should be in a layer that is vented, so that the condensate is evaporated when the temperature changes.

 

In insulating a boat, we should bear this in mind. We don't want the dew point to be on the steel, as that promotes rust. Ideally, we seal the steel surface - sprayfoam is the only guaranteed way of doing this, AFAIK.

 

If we can't seal the steel, then we need to give the condensation an escape route. Therefore it forming on your windows isn't necessarily a bad thing.

 

But if it's that humid inside the boat (can't see why it would be?), then surely the humidity will escape in order to equalise with the outside RH through your roof & door vents.

 

Also I don't think it's necessarily bad window design as Chris said. The condensation that forms on the window itself and the inside of the gutter will be drained, but there's not much a designer can do about condensation forming on the boat side of the gutter unless the gutter itself was made of a different material like plastic.

 

By the way, for those using bungs, has anyone found the foam shrinks with prolonged contact with the cold glass?

 

The washing up liquid idea seems ridiculous to me - who wants washing up liquid all over their window frames? How about clear silicone? No probably not...

Edited January 3, 2007 by blackrose

[elessina]

You are trying to hold the RH down to 40% in winter? That's awfully dry......

 

"Condensation has to go somewhere"

 

......we need to give the condensation an escape route. Therefore it forming on your windows isn't necessarily a bad thing.

But if the air is dry, then surely there is no condensation….. hence reason to get RH as low as possible. If I leave the dehumidifier on 'normal' setting, we have a RH of around 40%. Certainly we get less condensation when it is around 40% (as opposed to 50%). The window frame above the dehumidifier always has the least amount of condensation.

 

'Condensation has to go somewhere' – We have never seen any inside our house (UPVC windows), it is completely dry. Also wouldn't the dehumidifier be an obvious source for condensation to form on….. but that said on a cold night, even with the dehumidifier going all night we still get condensation on the window frames.

 

The issue with condensation on the window frames is that it will damage the surrounding wood frames, and stains the plywood underneath, so we mop up every night / morning – a pain!!.

 

But we do get some condensation in the bilges, on the steel sides under the floor, below water level, which has not been spray foamed. I guess if condensation on window frames were eliminated, then the condensation in the bilges would get worse….. 'condensation has to go somewhere'. At the moment this condensation in the bilges is very small, and normally dries up itself during the day, causing no harm (from the areas I can see / get access to).

 

The washing up liquid idea seems ridiculous to me - who wants washing up liquid all over their window frames? How about clear silicone? No probably not...

But it does work, for a night or two, until it is diluted with the condensation. I wondered if there was something else that might work, something that would repel water…. I tried Vaseline, did not work, and looked unsightly as it is a mat finish. Screwfix do sell an anti-condensation paint, but what colour / finish it gives is not apparent.

Ian

[Alastair]

The important thing is the relative humidity - and a RH of 40% in the middle of the boat may be 80% at floor level, and 80% near cold windows.

 

When I said the RH in York stays higher than 80%, I was talking about the RH in the outside air. You would have to have awfully dry air in your boat to not get condensation.

 

Air circulation is the key to keeping things healthy and mould-free.