Dehumidifiers

[capnahabParticipant @capnahab]

i need one for aDouble garage. It's been pretty damp generally recently but the lathe is getting some bright orange strain of rust in the odd place. i have read all the suggestions for avoiding rust. I reckon a small duhidifier could do. Can anyone recommend one ?.

[capnahabParticipant @capnahab]

[BrevaParticipant @breva]

I have a Dimplex model 2000 MKOC for quite a few years and it has given great service. Much more efficient than flashier looking models. Mine is dark brown, about 14" square and about 18" high. Don't know if they still produce these but they work well if you can find one.

John

[BazyleParticipant @bazyle]

Scewfix, about £135. I have recently got a dimplex. make sure you get one with a humidistat but a 2 speed fan is not necessary. Work on sealing the doors as best you can or you will be trying to dry out the world.

[David Clark 13Participant @davidclark13]

The larger one wil be best. Also you can use chemical tray that you can put on window ledges around the house on each machine.

[RobboParticipant @robbo]

I'm still using a Curry's own brand Matsui, bought over 20 years ago to help dry out plastering.

Its ugly and noisy but works a treat.

Obviously nowadays Currys has changed name, but any simple machine will do. As David says, restrict incoming damp air as much as is feasible

[Richard MarksParticipant @richardmarks80868]

Can recommend Meaco 20lt, bit noisy when on high but sucks up moisture like its going out of fashion, In my workshop I covered the walls in wood cladding and then varnished it this allows me to put up shelves etc and keeps the walls from condensing moisture also fitted old double glazed windows and a home made electric blind system that keeps anybody from looking in.

[MikeParticipant @mike89748]

Just out of curiosity, what's your garage roof made of? Mine was rust-proofed steel, and I had terrible condensation and rust problems. A couple of years ago I had it replaced with timber topped with a rubber-like compound. The chap who fitted it also cut a couple of holes in the concrete walls for ventilators. The result has been no condensation or rust, despite the fact that the garage is within 100 yards of the Moray Firth in the North of Scotland. It was an expensive operation (over £2,000), but the tools in the garage are worth much more than that.

[VicParticipant @vic]

There are different types of dehumifiers, have a read up on them as some don't work very well in cold conditions.

[Bill StarlingParticipant @billstarling10428]

If you are running any sort of small boiler, don't forget to collect all the condensate for use as feed water. No lime or other unwanted ingredients.

Bill.

[egaParticipant @ega]

Plus one for the Meaco. Mine, DD8L Junior Desiccant £150, also provides a modest increase in room temperature.

[Steve PaveyParticipant @stevepavey65865]

Baz and Mike have made the two important points – running a dehumidifier is pointless if there is any ventilation (designed or accidental), and similarly pointless if there is no adequate barrier to moisture penetrating the floor, walls or roof.

My first step would be to put a couple of low wattage tunsten filament lamps under the lathe, as a temporary but extremely effective measure. Next I'd look at insulation and the all-important vapour barrier on walls, floor and ceiling/roof.

[JAParticipant @ja]

Model Engineer's Workshop of November 2003 had an article on stopping rust on a lathe, Keeping Rust at Bay. It used three 50W resistors bolted to the back of the lathe. These were switched on by a temperature sensing circuit when the air temperature fell below the dew point.

I thought it a neat idea and would consider it if I had a rust problem.

JA

[John ShepherdParticipant @johnshepherd38883]

I help out in a small local museum and we have several portable dehumidifiers of different makes and age and all seem to work well enough. We take daily readings and aim for a relative humidity of about 45 to 55% which we achieve most of the time.

The latest two we bought were rated at 12 Litre (with 4 Litre tank) from Screwfix, when they were on offer at a about £100.00 each, they are now £130.00 I think.

I see Aldi have some on offer at £118.00 but I have no experience of them.

Hope that helps.

Regards John

[michael coleParticipant @michaelcole91146]

I have a cemet sheet and wood workshop, lined and insulation everywhere i could get it. There is a small gap at the bottom of the door which provides a draft. I do not have any rust problems but recently bought a very cheap Aldi dehumidifer around £20. My humidity hit a peak of 95%on a very wet day but normally around 70 %. But as I said no rust on any tools/matrials left out.

[john fletcher 1Participant @johnfletcher1]

Before spending a £100 or so on a dehumidifier, have a look in your local sale room, here they are all PAT tested and they give your a 24 hour guarantee. I've seen a lots for sale and they haven't made much. I've had one for at least 20 years and its worked wonders, as some one said they don't work at low temperature or mine doesn't. Insulation is the answer keep the workshop nice and warm, not forgetting the doors.John

[Chris Evans 6Participant @chrisevans6]

I bought one after suffering a water leak in the house, in a big area it did not seem to work that well. In my workshop I use a fan to move the air around and no rust issues. Worst thing for rust is a bottled gas heater, worse than a hose pipe in there.

[Steve WithnellParticipant @stevewithnell34426]

I did try a Humidifier a few years back. It was about £80 from B&Q. Lessons learned.

1. It didn't work when cold (say below 10C) but was ruthless at pulling out moisture in the house in the 18C+ range

2. It was expensive to run in the workshop, too much ventilation and the cold meant it was ineffective

Cheaper to throw a blanket over the machines and pop chucks and RT in zip lock bags. The use of resistors / low power lamps would be cheaper and more effective I think, I will get round to trying that one day.

 

Steve

Edited By Steve Withnell on 21/11/2015 20:14:58

[EmgeeParticipant @emgee]

As has been suggested cover the machines and run a low wattage lamp in the tent formed by the cover.

A dehumidifier in an uninsulated and unheated workshop is just throwing money to the supply company.

Emgee

[BazyleParticipant @bazyle]

In the UK it is not often below 4c on average so some thermal mass inside an insulated building will work most of the time, Once the humidity is reduced it will turn off so the average consumption is no more than the heaters suggested and protects all the loose stock material etc.

[DMBParticipant @dmb]

I have 4 old style bulbs in brass batten holders connected in series to reduce wattage to about 15. They are mounted in a box laid in drip tray of lathe. Switched on 24/7 for about 3/4 of year. Tent of plastic sheet over mill to trap low level heat. Just enough to ward off rust but inexpensive to run. Let’s say 15 Watts x 168 hours/week x 3/4 x 52weeks = 98280 Watts,just under 100 KWH./annually. I am currently paying 10.25p/unit so this costs about ?10.25 a year.

Edited By DMB on 21/11/2015 23:02:59

[DMBParticipant @dmb]

Lathe and large bench drill also covered with plastic sheet no heat. Insulated wooden shed.

[Johnboy25Participant @johnboy25]

I bought a Delongi dehumidifier after an auction that no one wanted for £3.45 to take it away! After checking the electrics out as a safety precaution, I plugged it in to find I needed to sort out the float switch. Then found it was the icing thermostat inhibit circuit not working. To check the unit I bridged out the icing inhibit – hey presto I had a working dehumidifier! Now to repair the icing inhibit stat.

The only potential problem is that it's got R22 refrigerant so when the units compressor finally gives up it will have to be disposed of correctly but they do this at the household waste recycling facility run by the council.

John

Edited By Johnboy25 on 22/11/2015 09:10:11

[Johnboy25Participant @johnboy25]

It's while now since I repaired the dehumidifier now looking at the last post. I've been using it intermittently during this wet period that we've been having. To my amazement, the unit has been extremely successful considering the state of my garage/workshop roof! For example, I wandered out into the workshop to find my cherished lathe and milling machine covered with condensatation droplets. Switching on the dehumidifier – after a couple of hours it dried the condensation up! I know I'm using more electricity when the unit is working, 0.4kWhr but the overal effect is extremely effective. (I'll just have to shorten to period my central heating is on to compensate for my carbon footprint!) 😳

Conclusion – if you are offered or can find one at a good price I recommend get it.

John

[peak4Participant @peak4]

Screwfix have a couple on offer at the moment, but I've no idea how good they are.

Just had a spot of bother with my workshop/shed, which it seems has been leaking with all the heavy rain we've just had. I put a new roof on over the weekend and am running a dehumidifier I got cheap from a neighbour when he was having a house moving sale.

It pulled out quite a bit the first night, then very little. I then went down yesterday and ran a fan heater for a couple of hours. This seemed to work and the gizmo pulled a load more water out last night. It's fairly well insulated and reasonably draft proof, barring the single glazing, so with the dehumidifier generating a bit of it's own heat and the residual heat from the fan heater, it seems to work well enough.

I'm not sure I'd want to leave it running full bore all the time though for cost reasons – it seems to be rated @ 250W

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