[Closed] Condensation and dehumidifiers

Re Hygrometer, I decided it was probs best to buy one that can be calibrated and buy a Boveda one step calibration kit at the same time. I think they say several hrs in a room for a proper reading, but IME you will see a change on the display quite quickly for an indication of roughly where things are at.
High and low are highest and lowest readings since your last reset /turned offon / took batteries out. main reading is current

We started to have a damp problem in our apartment. Buildings here cater for being cool in summer not warm in winter (we're in the Spanish Pyrenees).

Wet windows and window-ledges every morning and mound forming on some walls.

We have a couple of portable gas heaters which are apparently the worst culprits for this problem. We've found the only answer is to leave all the windows open a crack, even when it's cold outside.

Took a day to dry everything out but now it's actually less cold inside than it was when it was closed up but damp

t has a low and high humidity figure (52% to 69%) with a ‘big reading’ of 52.
what would that tell me? is it a range over 24 hrs or somethings and 52 is what it is now?

You whould be able to find a manual that tells you by googling the model.

High and low are highest and lowest readings since your last reset /turned offon / took batteries out. main reading is current

rightyo, thanks. ill go for somethings simple like that then. if i get any weird readings i believe i can check its effectiveness with the 'salt test', but it should be good enough to give readings of interest. only a tenner too.

cheers

High and low are highest and lowest readings since your last reset /turned offon / took batteries out. main reading is current

rightyo, thanks.

Er, just occurred to me, that's what mine does, what you're looking at buying might differ. as cynical says, the instruction manual for make/model you're considering will almost certainly be online

Likewise if you ever head further north and need assistance I have countless quality subbies

Cheers.

I have a very simple weather station like that and an extra probe. Right now it's 19 degrees and 53 humidity in my living room and the probe is reading 4.8 and 80% humidity in my fridge.
Bit off topic but was interested to see that thus morning all my windows were frosted up on the outside so I couldn't really see out apart from near the frames but none of my neighbours windows were like this. Is that due to my triple glazing?

if the soffit IS at fan level, preventing a straight run out, would i be better off making the hole lower and still using the flexi duct downwards instead of upwards?
was thinking of still trying to use solid pipe at an angle but not sure id be able to fix it all together in the tight space with an elbow say…..

anyone care to give advice on this please?

also, been googling making the 100mm hole. should i hire a diamond cutter (100mm?) and use it with an SDS drill? or a smaller sds bit and make lots of holes then chisel it out?

drilling everything from the inside, or inside and out meeting in the middle?

lastly (for now) will any flappy cover do for the outside, or will some not be able to cope with the amount of air moved? does the cover need to match the fan?

thanks

If it was me I would buy a decent extract fan and mount it so it was below the soffit. I would give it 10mm of fall to the outside using rigid pipe. The od of standard waste is 110mm so a 112mm diamond core is ideal. Get your measurements right and pilot a hole from inside. This pilot hole will then form a hole for the "centre guide" on the diamond core to get you started. Get up nice and high and hire a specific core drill and bit, far less painful when it grabs. Measure the depth of the core, once you are at this depth you will need to remove the inner leaf core if it hasn't already come loose to enable you to drill the outer leaf. Cut 110 pipe to length, fit fan and fit grill.

so leave the original crap one in place and drill a totally different hole then? so two fans on the wall, one in effect a dummy?

thanks

and is this one ok do you think? cant find that original fan in the 'max' version anywhere so just did a google search for centrifugal fans. the bumph is 25 cubic ft/min, how does that compare to the 123m3 of the blauberg?
manrose fan

I agree with wrightyson. Drill lower, I would be tempted to pipe out of the wall beyond the soffit. Otherwise your hot damp air might go up into the roof.
This is the fan I have coming for work to test. Mega output, works over long runs. https://www.fastlec.co.uk/ventilation-extractor-fans-vortice-extractor-fans-vortice-quadro-centrifugal-fans/

the bumph is 25 cubic ft/min, how does that compare to the 123m3 of the blauberg?

Well, the link you provided said 90m^3/hr in the description. So the other one provides ~1/3x more flow.
But flow isn't the be all and end all; you also need to see how much pressure the fan can generate and quite often as flow goes up, pressure generated goes down.
If your bathroom is 3*2*2m then that is 12m^3. So a 90m^3/hr fan will give you 7.5 air changes/hr or it takes 8 mins to change all the air in the room, theoretically of course!
Also check that the bathroom door isn't too tight. If there is nowhere for the fan to suck fresh air from, then you'll have very little flow.

If your bathroom is 3*2*2m then that is 12m^3. So a 90m^3/hr fan will give you 7.5 air changes/hr or it takes 8 mins to change all the air in the room, theoretically of course!

yep, i get you. but.....theoretically the fan i have now will officially move Xm3/hr, but it doesnt, it barely touches the air around it. i want something that really does shift that amount of air, something that sucks you into the bathroom as you walk past! 😀

Drill lower, I would be tempted to pipe out of the wall beyond the soffit. Otherwise your hot damp air might go up into the roof.

wouldnt that just result in a very unsightly 4" plastic pipe sticking 2ft or so out of my wall? i havent seen any other house with anything like that, are soffits likely to leak the moisture back into the roof?

thanks for the fan info, looks like my link wouldnt be sucking me into the bathroom any time soon then. have you got a link to anything suitable? the recommended fans so far dont seem to be for sale anywhere.....

thanks

yeah this one I linked to is in stock isn't it?
https://www.fastlec.co.uk/11989-vortice-quadro-super-hcs-surface-centrifugal-fan.html

ah yes it is, bit more expensive than id like to have paid, but as i always say, foolish to ask for advice and then not take it. unless theres a cheaper one thatd do a similar job? seems quite a large jump from the £35 of the blauberg....

right......ive been up in the loft looking to see whether i can finally put my mind to rest with the present bathroom extractor, and yep, theres no mileage in widening the current position, ill take the advice and fit a new one lower down and t'other side of the room.

im looking at doing the same in the kitchen, altho i found by accident that theres already something there, but i can see it being less use than the bathroom really.

there seems to be a small oblong hole going to the outside, got a plastic cover on the exterior wall, smaller than the bathroom tho and high up shielded by the cupboards.
would you agree thats next to useless?
any mileage in trying to cobble up something from that hood extractor to make it a bit better than charcoal filters? itd mean drilling a hole in the stainless steel tho and im not sure if thered be much benefit to it, what do you think?

and sorry, but we've just located ANOTHER damp issue........
i mentioned we're doing up our bedroom, until then we've moved our bed into our extension. looked today and theres damp plaster above the window.
im hoping this will be condensation too, but above a window? doesnt sound right.

i cant guarantee it hasnt been there all along, we've only just noticed it since moving into the room. its a west facing wall, newish extension (5 years or so) and a flat roof. no pipes or anything and no access to it. ive been up the ladder and cant see anything suspicious and it hasnt been raining lately, just the odd bit of snow.

wotcha reckon to all this, its a game innit :-/

That hole would have possiblybbeen for a previous extractor, you can rigid duct that shape which is ideal for in stud work or for on top of units as it wouldn't be visible.
As for the window I'd very much doubt that would be condensation, the thermal break in the frame would tend to prevent that from happening. Window looks very close to the reveal and it could easily be water tracking across the lintel from a poor silicone seal at the head.

You can cut a hole in the stainless with either tin snips or a drill powered nibbler.
This clarkes one works well for one off jobs.

https://www.machinemart.co.uk/p/clarke-dhc-2-double-headed-metal-nibbler/

I would defo sort the kitchen. We use either 110 soil or 100m white extraction round pipes. if you are drilling in the bathroom, drill out where that oblong is.

As regards the new damp - listen to wrightyson.
we have stripped and re siliconed around a few DG windows with lintels above like that, I think it is due to this. I'll ask the contractors on monday.

To understand the lintel issue - look at this. https://keystonelintels.com/products/steel-lintels/
see how the lintel is directly above the UPVC. If the seal between the window and the lintel is crap than the water can track across and make the inside plaster damp.

Window looks very close to the reveal and it could easily be water tracking across the lintel from a poor silicone seal at the head.

got to admit i dont know what that means..... dont windows just plop into the hole thats there, so what are you saying is different to other windows?
and where is 'the head'? how can i check water ingress? is it going to be stripping the plaster back? :-/

if you are drilling in the bathroom, drill out where that oblong is.

that oblong is in the kitchen. if i was to use that id be drilling into the stainless extractor and attaching some sort of duct. im thinking that wouldnt be enough tho, id still need a superduper extractor on the wall too wouldnt i?

thanks

EDIT as typing at same time as you....

see how the lintel is directly above the UPVC. If the seal between the window and the lintel is crap than the water can track across and make the inside plaster damp.

must admit im still a little lost, but i accept this explanation 🙂
question is tho, what water? wheres it coming from? we havent had any rain for a while....

If a flat level plate gets wet, the water will "wet" out, I spread out, if it is on top of the plate, or underneath it.
Possible the lintel might be slightly tipped back so the bottom plate goes down hill into the house.
Just clean off and re silicon.

The extract fan will probably be enough, if it doesn't work you can put in inline 100m fan along the length of tube. They are very good.
https://www.i-sells.co.uk/domus-vitalis-high-performance-mixed-flow-in-line-shower-100mm-fan-white?

Just clean off and re silicon.

you do mean after stripping plaster tho yep? no way around that? ive asked the original builder to pop round tomorrow, ill let you know what he says.

The extract fan will probably be enough, if it doesn’t work you can put in inline 100m fan along the length of tube. They are very good.

we're talking about that little oblong kitchen hole now arent we? so you think the howdens extractor fan would be good enough to remove the cooking condensation, and maybe boosted by one of those fans yep?
and if so, i assume theres no point going 100mm ducting up there as thatd be bigger than the hole, which is its weak point yep?

thanks

EDIT: just been looking again and i think you have to use 100mm ducting, so maybe reducing down with an adaptor at the end to fit the oblong hole?

Back to basics then young man 😂.
Basically your window frame isn't very far in reveal, as in set back from the face of the brickwork. This can sometimes leave them a little exposed. The silicone we are referring to is the silicone around the outside of the window which creates the seal between window and brickwork, after time it can shrink a bit and leave small cracks for water to penetrate. It was just a thought, it may not be that, have a good look at the sealing around the head of the window (the top). HTH

1) Kitchen extraction and oblong hole.
I would brick up the oblong hole inside and out.
Dismantle the stainless chimney to see what heights everything is - you will need a 90 bend outlet from the top of the fan.
Then drill a round hole at the right height in the area where the oblong hole is to take 100 or 110m round pipe.
Use the nibbler to cut into the stainless chimney.
The fan in the hood will be a centrifugal one, it will be pretty pokey. If after you have installed an exit pipe you feel there is not enough punch, then fit the in line one, you could remove the fan from the hood and run the inline one on its own. There will be a controls issue you will have to solve, so probs the light on the hood will work, and have a separate switch for the inline fan.
it is possible a decent electrician can wire them up together, but some of the fans are 12v,
I doubt it will be necessary to fit the inline fan too though.

2) Bathroom extraction - that fan I recommended is uber powerful...

3) Damp above window. as wrightson says I mean take the silicon off the outside. And reseal around the window and where the window meets the lintel.

Hood ducting concepts here.
https://www.kitchenhoods.ca/shop/how-to-install-range-hood

Back to basics then young man

thank you, every days a learning day 😀

Basically your window frame isn’t very far in reveal, as in set back from the face of the brickwork. This can sometimes leave them a little exposed.

ahhhh i see what you mean.

just been out for another look, then looked at rest of the hose and neighbours, and theyre all the same, so must be fairly normal? builder probs just wanted to make it all match. i get the exposure thing tho, its very bleak on that side of the house, overlooking fields and on top of a hill, altho..... like i said, it hasnt rained.

The silicone we are referring to is the silicone around the outside of the window which creates the seal between window and brickwork, after time it can shrink a bit and leave small cracks for water to penetrate. It was just a thought, it may not be that, have a good look at the sealing around the head of the window (the top). HTH

gotcha! again, been out to look at what you mean and er...... there isnt any silicone! i can see the steel lintel, and mortar but no silicone. and maybe more telling, i can see a gap where the windows settled?

I would brick up the oblong hole inside and out.

Then drill a round hole at the right height in the area where the oblong hole is to take 100 or 110m round pipe.

brick up to drill again? i assume this is so there can be a pilot hole for the big hole saw yep?

2) Bathroom extraction – that fan I recommended is uber powerful…

which is what i asked for, so ill order it. (you do mean the vortice quandro dont you)

thank you both.

brick up to drill again? i assume this is so there can be a pilot hole for the big hole saw yep?

Yes. The flow area of those oblongs are a bit crap, we prefer a decent round tube...

which is what i asked for, so ill order it. (you do mean the vortice quandro dont you)

Yes Vortice Quadro Super THCS Surface Centrifugal Fan
https://www.fastlec.co.uk/11989-vortice-quadro-super-hcs-surface-centrifugal-fan.htmlIt has humidistat, timer, two speeds, its bigger than the 100mm hole. check the dims here.

thank you both.

You are on a forum where everyone loves to be right and admire the sound of their own voices, thank you for providing us with the opportunity to drone on and on..

That's you guilty party! Fill that gap with clear slicone, nice thin nozzle and gun it in, if you look at your pic there is white silicone between the u/s of the lintel and frame and that looks ok.

As we're working as a team, 5plus and I will split the 500+vat, you know fairs fair and all. 😁
Hope you get sorted, good luck.

As we’re working as a team, 5plus and I will split the 500+vat, you know fairs fair and all.

😀

Yes. The flow area of those oblongs are a bit crap, we prefer a decent round tube…

and its not viable to maybe chisel the hole bigger than brick up and re-drill?

I prefer the neatness of a core drill, otherwise you have a shite making good mission around your pipe. Better to make it good first, then drill a super neat hole, making good is a piece of piss then.
Also a core drill needs to be done in a complete wall really, otherwise it makes it difficult to keep it steady.

FYI, wrightyson should get his day rate. I just do inspections beginning and end. Give him all the £500+ vat. I just need my £1500 + vat by bank transfer.

does my gratitude and respect not mean more to you than financial gain?

fan ordered 😉

Its not gain, its compensation for giving up our time.

Regarding the square hole in the kitchen and associated ducting....this is exactly what we have for our extractor fan and it works fine.
So, the top of the extractor connects into the rectangular ducting that runs along the top of the cupboards and out the wall.

It must be working ok as when i come home from work I can often work out what is for dinner as soon as i get out the car because of the extracted food smells!
Whether it's better than 100mm round ducting, i am not sure, but i would expect if the x-section area was broadly the same as a 100mm circle then it should be pretty much the same.

If you want to compare the difference between rectangular ducting to round, this mught help:

http://www.pressure-drop.com/Online-Calculator/

sorry if already covered, I can't be bothered to read through 3+ pages agan, but with the bathroom fan...the existing naff one...do you have anywhere for the air to enter the bathroom? leave the door open or a couple of goo sized vents in the door? if not, no fan will extract well

ok, update time......

builder has been round and kyboshed some of these plans.

looked at the kitchen and said nope, window lintel will be in the way of drilling a 100mm hole. yes, we could fill in the oblong hole and re-drill but he'd be happy with trying the oblong hole first for the price of a bit of ducting. ive now stripped the extractor fan down to see what we've got. this is how it looks, its a 120mm extractor, and hopefully screwfix will sell some sort of 'oblong to round adaptor'.

would you agree this is worth trying? only thing ill have to do now is get a hole cut in the stainless for some ducting.

he looked at the bathroom and said nope, not enough room for another hole. if you want one lower to miss the soffit, thered now be the window lintel in its way. go even lower and youre not sposed to drill under a lintel and itd look crap halfway down a wall anyway.
on the plus side he said hes sure that the original hole will be the right size so nothing lost trying it. happily hes right, id got me sizes wrong and hole and flexi ducting are indeed 100mm so i should be able to just swap and try.

new fan has come, the vortice quadro and wow! was not expecting one that size, its like a 'kin air conditioning unit!! thought theres no way thatll fit in that corner, but if i spin it 90 degrees itll fit as the duct is offset at the back.
unfortunately the wiring wont reach now so ill have to extend it. which brings me to next question.....
the fan ive taken down looks like it was on a ring which serves the hall/bathroom/toilet lighting, plus the security alarm. theres no chance that as this is a monster fan, that itll need to go on a socket ring main or owt is there? i should be able to use the original wiring extended with a couple of block adaptors?

also, he looked at the window and said it just needs re-pointing which hes going to do for us.

cheers

Got a battery power drill? Get this, it'll cut the stainless and is easy to use/ do neatly

https://www.amazon.co.uk/dp/B07FVY6L9J/ref=asc_df_B07FVY6L9J58373703/?tag=googshopuk-21&creative=22122&creativeASIN=B07FVY6L9J&linkCode=df0&hvadid=271972947501&hvpos=1o4&hvnetw=g&hvrand=6570847697711074395&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9045889&hvtargid=pla-540261566574

Check the power and recommended fuse for the fan, I'm pretty sure you'll be fine on a 5amp lighting circuit.

Have you got vents in the bathroom door or some way to let air in? Else the fan will still struggle.

Thanks, that looks a nifty little tool.

couldnt find much info in the bumph, its a bit minimal, ill have another look in the morning, im sure itll be in there somewhere.

no vents in door. cant believe we're going from worrying about a fan not working at all, to trying to stop the door being sucked off its hinges 😀
spose we'd just have to keep door closed whilst in the bath and then whereas we'd usually open a window and close the door, now we'd keep it open straight away....

thanks

i didn't check the specs, just googled nibbler, scrolled the answers to find the drill powered type, selected that as it was cheap and amazon. somewhere it will have the spec on max thickness of sheet in different materials...stainless probably about 1.5mm and the hood you have is likely about 0.8mm-1mm

sorry, i meant i didnt check the electric specs of the fan to see if its compatible with my existing wiring 🙂

thanks

just looking at starting to wire the fan in. looking at this link to the documents, am i right in thinking you can choose between two speeds on it?