Dehumidifier and humidistats question.

[T i m]

Hi All,

I'm doing some experiments re clothes drying [1] (as read about here a while back) using one of these:

already had it and when used in our little bathroom (wheeled out when someone actually using the room) it seems to be able to fill up it's tank in about a day of constant running (5l I think).

However, the rotary stat has a 'normal' position but when set there the thing seems to run 24/7? So does this suggest this room is taking a lot of drying out (fabric of the building and room contents etc) or that this stat isn't very accurate and it's trying to de-humidify the world (my current thought).

So, are there any external humidistats out there that would switch this sort of appliance (300W but probably pretty inductive) that are accurate whilst being reasonably priced please? I don't really want to spend £150 on a stat when I might be able to pick up a better unit with one already fitted etc?

Manrose do a little retro-fit stat (0950) but it only supports loads of up to 200W and I have no idea if it would be any better / more accurate / responsive than the built in jobby? You can turn the stat down to a point where it seems it could actually be doing something but it's probably then on 2 of a range of 10 (where 7 is marked 'Normal').

I also need a decent (as in accuracy) hygrometer so I can actually see what is really going on in there (advice on that also welcomed).

Cheers, T i m

[1] Stuff like daughters chainsaw protection trousers and motorcycle gear etc.

[John Stumbles]

Couldn't you just re-label it so it goes up to 11? ;-)

There are loads of cheap Chinese hygrometers and so on if you Google - I just bought a combined pH meter, thermometer and hygrometer for about £25. (They said it would take a few weeks to arrive but it came within about one week.)

I think it claims reasonable accuracy, though I don't know how one would tell.

[T i m]

Hehe.

A nice surprise.

Difficult isn't it (without some means of calibration). Noting so rewarding as putting 2+ meters side_by_side and seeing them read the same thing (even if they are both off!). ;-)

For my purposes something that actually showed with some level of repeatability an approximate level of humidity would be good enough, before (de-humidifier) and after etc. It would be nice to know the real / absolute reading of course but not at 'any" price. I'm not sure what I would do with the info in any case?

Cheers, T i m

p.s. I now have a couple of those IBT-Gold battery capacity meters I mentioned a while back and unfortunately both had broken leads. I have replaced one with a pair of new similar looking / size / spec leads and it's now *way* out. I've even gone from ~40cm to the full length of wire supplied (about 75cm x 2) and it still reads way high. At least the one with just a repaired / shortened lead gives a semi-realistic reading! ;-)

[John Stumbles]

Or not, as the case may be: I have 2 'Laser' DMM-with-thermocouple meters ... :-(

You could probably DIY a wet-bulb hygrometer. AIUI it comprises 2 mercury-bulb thermometers, a bit of muslin (praise be to Allah the most merciful! oh sorry not that one :-)) and some distilled water. And some maffs.

[newshound]

I bought a digital combined hygrometer and thermometer (for my snake vivarium) off eBay for about £12 and it seems to be pretty sensitive

[Andrew Gabriel]

Go to a garden centre and buy a small greenhouse hygrometer. I think I picked one up for less than a quid some years back.

[T i m]

Thanks. I had a look in Homebase and Wickes and neither had anything but I was going to look in a garden centre or pet shop the next time I was passing.

Would you say the one you bought reflects the general humidity ok? Have you had chance to compare it with another? I ask because I have an electronic multifunction gauge with humidity readout and whilst it did show some variation between the lounge and my test room it returned to displaying the same value after a minute or two (which I wasn't sure was what I expected)?

Cheers, T i m

[T i m]

Hmm, I was ok till the last bit! ;-)

T i m

[T i m]

I had seen those combined units and was happy to get one or two, so I can compare their readouts. Then I could keep one in the test room and one elsewhere to see how different the test room can go.

Cheers, T i m