Generally, here when temps that low condensation is not a problem. Can't say my Hotpoint has ever frozen, presumably because the stat cuts it out at lower temps/moisture levels.
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It's also worth spending time considering the likely sources of moisture in the workshop air, when considering a decision on how to tackle rusting on machinery. Human activity shouldn't be ignored, since we give off a fair bit of moisture in exhaled air and sweat, then there are open flames e.g. space heaters, propane torches, forges, and there's dampness coming through floors, walls, and ceilings, then there are processes, like electroplating, which tend to produce corrosive aerosols as well as moisture. Draughts will rend to rais humidity if the air outside is humid, but will also reduce humidity, if the air outside is relatively dry.
A dehumidifier on its own, will almost certainly make a difference to an existing situation, but it's worth considering the other factors, too.
A dehumidifier on its own, will almost certainly make a difference to an existing situation, but it's worth considering the other factors, too.
My workshop was a nightmare before I sorted it out - single skin brickwork and fibre cement roofing. Put a proper pitched roof on it, and sorted out breathable membrane and vapour barrier plus insulation everywhere possible. I occasionally put some heating on, and make sure I keep the doors closed whenever it’s damp. I get very little condensation now, but this last temperature change nearly caught me out - it’s always the nice machined surfaces that catch the worst of it of course, but a bit of wd40 and oil sorts it out.
No condensation issues in mine at all. Because ive got 4 dehumidifiers running 24/7. Downside is, thats no cheap excercise over 5-6 months. But, its sitting at around 60% gefore Bert arrived and climbed to circa 65 peak.
Its a 3000sq/ft double height building though. According to the specs, there should be no chance of the 4 little ones doing it, but they do. Just need to ensure the big door isnt open for extended peroids.
Previously ive plugged all the gaps so little outside air can get in.
Its a 3000sq/ft double height building though. According to the specs, there should be no chance of the 4 little ones doing it, but they do. Just need to ensure the big door isnt open for extended peroids.
Previously ive plugged all the gaps so little outside air can get in.
Breathable construction is your friend, if you have solid stone walls. Gas diffusion through solid materials is significant. Also insulations like woodfibre, covered with dense vapour-permeable sheets such as clay boards are brilliant as they not only provide thermal mass and insulation, but act as a moisture buffer. Dampness is absorbed at periods of high humidity and released as the vapour gradient changes. It might be a long shot as the single form of protection in a draughty garage, but if you're insulating already then it'll certainly be a great help to a dehumidifier. This humidity buffering technique is a common alternative in Europe to the ceramic tiles we like over here in bathrooms, as condensation is drastically reduced.
Theblackbox
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Interested to hear which make/model you are using.
today all the condensation seemed to disappear guess the machines had warmed up a bit!
Smouser
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My double garage is not insulated and fairly 'leaky'. I can see air gaps around both garage doors.
I don't think a dehumidifier or even two will work for me. I really don't know what the solution is.
Oil and a fan is the best I can do at the moment.
I don't think a dehumidifier or even two will work for me. I really don't know what the solution is.
Oil and a fan is the best I can do at the moment.
Jelly_Sheffield
Time is an illusion. Lunchtime doubly so.
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I find insulation makes a surprising difference to stabilising the temperature against rapid swings, pushing back the time of year that you need to start putting energy in.wont make any odds unless you heat it as well
I have noticed that with the extended bursts of relatively clement weather the internal temp of the workshop has held for a pretty long time, and the dehumidifier has not had to kick in all that much this year.
The dehumidifier is on a controller with a couple of temperature sensors attached to heavy metal items, and a humidity sensor, so that it will cut in just enough to ensure that the dew-point is below the temperature of the machine tools.
I only heat the space when it's occupied, and I have had zero issues with rust since the dehumidifier went in, which is superior results to when I heated it for a tiny fraction of the energy consumption that required.
Im using these: https://www.meaco.com/products/meaco-dd8l-zambezi-dehumidifier
They do the job, but they do seem rather fault prone popping up errors on a regular basis. Switching on and off gets them going again.
In my experience all these cheap units are exactly that cheap. Not built to last.
At the moment, with a single skin roof, and hence no insulating effect to speak of, its my only option. The quote for a new roof was just shy of 50K! Wont be doing that any time soon!
Seal the gaps.
Trying to heat is just as fultile with gaps. Worse than trying to dehumidify it it, as moist air will continue to come in regardless.
This^^^^ To say you need to heat it as well is to misundertand the problem.
Jelly_Sheffield
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Exactly the bottom line is that as humidity goes up, and the temperature goes down... You will have to put energy in to either:
• increase the enthalpy to the air keep the water as vapour, or
• do work to physically remove it from the air
I think it's forgivable to make heat the default assumption though.
Most dehumidifiers are the refrigerant type which rapidly loses effectiveness in single digit temps, so you still need to add at least a bit of heat to use them.
I am quite fortunate to have stumbled on a big Munters desiccant type dehumidifier that will remove 1kg of water per hour (at 100% RH and 20°C there's about 17g of water per cubic metre).
It takes a minute to wrap your head round all the moving parts of how you use pure dessication to prevent rust, but it is the single most effective solution.
As it happens there's a guy selling off five MH300M desiccant dehumidifiers (about twice the rated capacity of mine) on eBay at the moment...
He wants £199 each, but when you consider they're £1,976 new it's a bit of a steal.
mark roberts
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I just got a military tent heater to try and prevent rust, also make it bearable to be in the shed when its cold
MattF
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That's my approach.
Looks a good deal. But all he needs to do to test them is get a 110V transformer. Then they are worth much more. Im not convinced all is as it seems.
Morrisman
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My bungalow has solid concrete floors throughout, when we first moved in, early one March, it had been empty for 6 months, no heating apart from frost stat.
It took 3 days with the central heating running constantly to get the inside temp up to a reasonable level. It was just chilled to the core.
The previous owner spent his life in a wheelchair, so the floors have a basic thin layer of carpet, no shag pile and thick underlay.
Jelly_Sheffield
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If you look at his other items, it appears he just sells random secondhand stuff... So probably just wants to shift these 5 big objects at a profit to him for minimal effort.
I do agree that if I was selling it would be worth the effort to test and then sell for market value... But I also have a transformer & cables and understand what they're worth.
The best deals always come from sellers who don't really understand what it is they have, but so does the highest risk!
not done it yet
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Can’t argue with that. It’s just that my approach is the opposite. In my situation the extra cost in running the desiccant heater saves me heating the workshop.
‘Orses fer courses’.
MattF
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It is. It was a toss-up for me as to which type I went with.
