How do you fight workshop/shed condensation

[ronan walshParticipant @ronanwalsh98054]

The dreaded condesation has returned to my shed for the first time this winter. Went into the shed today and was shocked at the amount of water condensed on my old mill, i could have sponged it off there was so much. Time to insulate the building me thinks and find some way of heating it that doesn't cost a bomb.

How do you fight this destructive pest ?

[ronan walshParticipant @ronanwalsh98054]

[Thor 🇳🇴Participant @thor]

Hi Ronan,

this topic has been discussed before:

***LINK***

Have you read it?

Thor

[michael coleParticipant @michaelcole91146]

If you only do one thing then that has to be insulate.

[john fletcher 1Participant @johnfletcher1]

Insulate as Thor says and then get a dehumidifier, they don't use a lot of electrical energy as they cycle on and off as necessary. Look out at sale rooms for cheap buys or buy new.I can recommend them, I've had one for the past 20 years pre owned. Alternatively get some bags of selica gel and dangle them around, they will change colour as they absorbe the moisture, but they will need drying out as and when necessary.Ted

[Bob YouldonParticipant @bobyouldon45599]

Condensation can be managed but the elimination of the problem may involve some drastic action. You don’t say what method of construction your workshop is, the worst cases are the concrete garage shared with the car. The type of construction does determine the type of action required, to combat the condensation problem. Insulation is imperative and needs to be installed with a vapour barrier if it is to be effective. You need to determine where the condensate laden air enters the space and seal off any voids and gaps around ill fitting doors etc. a concrete floor can be a problem if no insulation was incorporated in the original build, there are specialist products able to deal with this type of problem although a vapour barrier and an industrial grade floor covering will much reduce any condensation from this source.

Ventilation is important and modern heat recovery units are the way forward, particularly effective with today’s spiralling energy costs, see **LINK**

The provision of some background heat is also necessary in lifting the dew point; this may be done with a simple electric tubular type heater, although I find a wall mounted fan heater far more effective as air circulation around machinery, benches etc is so important, see, Dimplex PFH30 3kw Commercial Fan Heater (DIMPFH30)

There is little doubt good insulation to all surfaces, with correct ventilation will deal with the condensation problem once and for all.

Bob Youldon

[Michael GilliganParticipant @michaelgilligan61133]

My workshop is well insulated, but: For extra confidence, I have a 150 Watt "heating cable" that I just drape over the machines. The element is about 10ft long and was intended for horticultural use. It provides a warm micro-climate just where it's needed.

Thinks: You could probably strip the cable out of an old electric blanket

MichaelG.

[David Clark 13Participant @davidclark13]

Large dehumidifier and empty it daily.

Tubular greenhouse heater behind the lathe cabinet if possible, available on Ebay.

Little trays of chemicals sold for putting on radiators.

I used a blanket over the lathe for two years with no rust but others may not recomend this as theoretically it attracts water.

[Jerry WrayParticipant @jerrywray14030]

David,

What do you mean by a large dehumidifier? My garagve workshop is about 20'x10'

JerryNotts

[BazyleParticipant @bazyle]

A natural fibre blanket or sheet is a good idea David as the fibres actually absorb moisture whereas synthetic just has little droplets on its surface which can then contact the metal. A few bamboo sticks can help reduce contact with the machine.

Humans breath out and sweat up to 6 pints of water per day. That's to give you an idea of the problem you yourself create. So those little chemical packs haven't a hope except inside small toolboxes.
The first thing should be draught control to stop wet air coming in . Then some of the mositure can either condense on the inside of the roof or the window in preferance to the tools. A dehumidifier positively removes it. I don't have to empty mine every week once it had sucked the damp out of the structure.

Ventilation is essential once you are in there to remove the fumes and oil vapour but not moisture. The air should be dry enough from your dehumidifier to take a pint or two from you.

If possible heat the tool not the room, that way the tool is hotest and won't attract damp.

[Ady1Participant @ady1]

I used a blanket over the lathe for two years with no rust but others may not recomend this as theoretically it attracts water.

That's the cheapest simplest approach

I presume it stops moist air circulating around the object, but unlike with plastic etc, evaporation is possible

[jason udallParticipant @jasonudall57142]

Condensation comes from water vapour in air . This happens when the ability of air to hold moisture drops below the amount in the air..

This is why they talk about RELATIVE humidity. .
So air comes into contact with cold mc..condensation happens..
OK insulate is the cry..
Well it helps in part ..1 seal up drafts..2 makes temp changes within workshop slower..3 allows a little heating to keep all in workshop above the dew point..

Frankly short of anti condensation heating ( cheaper than dehumidifiers..unless workshop is air tight) .. all insulation does is slow down the temp drop…
As to anti condensation heating ..well the dehumidifier works as a heat source..as would the same wattage of lighting…added bonus there makes ws look occupied…

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by jason udall on 12/11/2013 15:05:46:
So air comes into contact with cold mc..condensation happens..
OK insulate is the cry..

. . . or raise the temperature of the machine slightly above ambient. When I lived in the UK I just threw a dustsheet over the lathe and put a 50 W bulb in the stand. Never had any problem with condensation.

Of course you could always move to a warmer, dryer climate

Russell.

[NJHParticipant @njh]

Jason U says " .…all insulation does is slow down the temp drop…" and this slowing down is really the key.

I have , as John (Bogs) advocates, a small thermostatically controlled oil filled radiator which I run in the months November to April. I took a deal of trouble to insulate my workshop and have monitored internal and external temperature, dew point and heating used on a daily basis for some years. As an example the total cost of heating for 2012 was £15.57. It works BUT you must have good insulation – without it there will be rapid swings in temperature with consequent condensation as the dew point is crossed. A dehumidifier may well be useful to remove some of the moisture from the air – if the air is dry then there IS no moisture to condense. I don't know the relative costs of heating against dehumidifying but a warmer workshop is nicer to work in and the heating helps with that!

Norman

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Jerry Wray on 12/11/2013 13:34:53:

David,

What do you mean by a large dehumidifier? My garagve workshop is about 20'x10'

JerryNotts

.

Jerry,

Unless the room is almost sealed [unlikely, if it's a garage] you would be trying to dehumidify the Planet … in which case "Large" = "Unimaginably Large".

Much more realistic to do what I, and others, have suggested; provide some local warmth around the machines.

There will probably still be condensation somewhere in the room … but you can move it to where it does less damage.

MichaelG.

.

P.S. What is the construction of the garage, and do you still use it as such?

[Sub MandrelParticipant @submandrel]

I have a well insulated workshop, and over the past eleven winters years, heated or not, I have only suffered enough rust to cover an after eight.

I have a heater I put on anti-frost in very cold weather, or to heat it up when I go in.

Neil

[nigel jones 5Participant @nigeljones5]

I bought a b&q dehumidifier oft ebay – works brill!!

[wendy jacksonParticipant @wendyjackson]

Hi, I have insulated the workshop which helped.but last year there was signs of rust on machined surfaces. This year I added a small dehumidifier plumbed to release the water outside.at the begaining of using the dehumidifier water was pouring out most of the day.these days next to nothing.no more rust, and the newspaper always forgotten remains dry.the cost of running is very low as the machine only starts up if needed.michael

[Mark P.Participant @markp]

I tend to open a window and put a wooly on. Also I slap oil all over the place.

Mark P.

[davebParticipant @daveb17630]

Be careful with the dehumidifers, dry air can cause irritation of the nose and throat and mummification of everything else.

[David Clark 13Participant @davidclark13]

Hi Jerry

Large yellow one from Argos.

Did a three bedroom bungalow.

regards david

[wendy jacksonParticipant @wendyjackson]

Posted by daveb on 12/11/2013 19:55:37:

Be careful with the dehumidifers, dry air can cause irritation of the nose and throat and mummification of everything else.

if the room, workshop what ever is a sealed place then yes. most workshops including mine are far from it. the dehumidifier is only plugged in last thing as I leave so never in anyway harmful. michael

[ronan walshParticipant @ronanwalsh98054]

Posted by Mark P. on 12/11/2013 19:50:00:

I tend to open a window and put a wooly on. Also I slap oil all over the place.

Mark P.

I was doing that, but the oil tended to emulsify and act like a poultice on the bare metal. strangely i went out to the shed today and the machines were fine , no condensation to be seen, the uni-bond humidity absorbers did have some water in them though.

The shed itself is the usual cavity cement block construction with concrete floor. I wouldn't have built it like that personally, the father built it and its not a good job.

[Steve WithnellParticipant @stevewithnell34426]

There are two problems with de-humidifiers – quite expensive to run and the typical ones don't work at low temperatures. They work well at 20C and pretty much not at all below 5C. I found it easier to stop heating the workshop and to keep machines covered up and things like chucks etc in zip lock bags. Keeping chucks in bags aslo keeps any avoidable dirt out.

One thing that will cause condensation is the sun streaming in on a cold winter's day. Everything warms up, sun goes down, condensation forms.

[ronan walshParticipant @ronanwalsh98054]

Posted by Steve Withnell on 12/11/2013 21:09:01:

One thing that will cause condensation is the sun streaming in on a cold winter's day. Everything warms up, sun goes down, condensation forms.

I had wondered about the effect of a large window (which it has) on the condensation situation in the shed. Natural light is so much nicer to work in than artifical light though.

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