Alan PT

Yes, it's that time of year again in Portugal

Having struggled with a couple of apartments which were very effective mould farms, we put a heat recovery ventilation system in our current place (despite being very common in France, they are almost unknown in Portugal, so it took a bit of persuasion to get our builder to cooperate!)

This keeps things in the low to mid 60% range, though kitchen and bathroom can get into the 70% range with use. Not bad for a Portuguese house, but we still discover the odd patch of mould behind a cupboard from time to time (that fibre board which Ikea use seems particularly susceptible)

So, having become bored of accidentally knocking over those little plastic supermarket dehumidifiers and creating a sticky mess, I set off on the search for a compressor type dehumidifier. The most recommended by far in the UK seems to be Meaco, but they only sell (and ship) within UK, Germany and France. They have a blank space next to Portugal in their resellers list: https://www.meaco.com/pages/international-sellers

However, it appears that you can buy direct from them (their Germany branch) via Worten Marketplace - only a couple of the low end models but still good to discover, thought I'd pass it on in case anyone else was on the lookout for one: https://www.worten.pt/grandes-eletro...es-marca-meaco

Only slight flaw is that shipping is quoted "6 to 13 days", so I'll report back on how it is working sometime in January I guess!

macliam

We bought one from Worten last year and it ahas been excellent.
I think it was about €160 - I decided to go that way because, if there's an issue, sending a lump like that back to the UK or Germany would be a real PITA.

The amount of moisture it can extract is amazing........ and the difference it makes is really noticeable.

Alan PT

Thanks, good to know it has been a success for you! Looking forward to it coming now

I'm not too worried about it coming from Germany - some other companies also ship from there when you buy from their "Portuguese" online shop - Grohe and Zooplus come to mind. But I can't imagine the hassle and paperwork that could be involved in sending something back to the UK these days, definitely best avoided

Mitzi2012

I have purchased two different Probreeze models via Amazon Spain. Very happy with them.

liveaboard

I'm afraid a dehumidifier won't work well when you also have a HRV system working; your air is constantly being changed, which is a good thing, but it also means that the dehumidified air is constantly being expelled and replaced with untreated air.

I have the same situation; the HRV system keeps the humidity in the house quite low most of the time, but cupboards against cold walls still have a mold problem.
I have insulated behind some, and that works well. even a thin layer of closed cell foam seems to so the trick.
One clothing cupboard I put a 10w light bulb underneath to add a little heat, just 5 degrees is enough to increase the saturation point of the air enough to decrease the relative humidity and stop mold growth.

Or as you had before, those chemical water absorber things inside the problem spaces where air exchange is much slower.

Anyway, you've already ordered it so give it a try and let us know how it goes.

wellinever

Need to be careful over dehumidifying the air if you are living in the property.
Very dry air can lead to worsening of Sinus issues, as well as eyes.
Better to open the doors windows for bursts to move the air

Alan PT

Interesting thoughts thanks. It's a new house, so the natural ventilation rates are very low (did you install HRV for the same reason?). We also have a timer on the HRV (our builder was worried about it costing too much to run, not sure why) so we could tweak it a bit to run at different times

Even if it just takes the level down quicker in the kitchen and bathroom that's a bonus. But I'll check back in January and let you know how it's going

Oddly enough, we don't have a problem with the stuff in the cupboards going mouldy - it's the actual cupboards! Slowly stripping that damn particle board out of items...

Alan PT

I read somewhere that 40-60% was the ideal range, chances of getting below that in Portugal surely must be quite small?

macliam

That's quite a specific circimstance and not very common in Portugal..... however, even in a "normal" environment a dehumidifier is not a magic bullet. Where you have the damp equivalent of "hot spots" (i.e. cold external walls within cupbards), you will still need to take extra measures as you would have to drop the general humidity to an unfeasible level to ensure there is no condensation at all.
This is true, but unlikely to be an issue. Most dehumidifiers measure the humitidy and/or allow you to set a maximum/minimum level - and if there are any "side-effects" the cause is easily remedied.

There is a simple test/rule of thumb for unhealthily low humidity:
a) Put 3 ice cubes into a glass of water and stir
b) Leave 5 minutes
c) If no moisture forms on the outside of the glass, the relative humidity of the air is too low

liveaboard

I think your cupboard material has absorbed some excess moisture at some point, and when it cools down a little your problem starts. Hopefully your dehumidifier will dry it up.
There are small digital moisture detectors, they have 2 prongs you push into the wood and they'll tell you the approximate moisture content. Aldi sells them sometimes, or ebay, 10-20 euros.
The reading should be under 18%.

We bought an oldish house and renovated it; I insulated the ceilings and floors but there's no insulation in the walls.
My OH is very sensitive to mold and odor, and couldn't bear being in the house at first, so I installed the heat recovery ventilation system.
I bought it from Rolear in Lagos, he had it in a catalog but he said he'd never sold one before.

It runs 24/7 for the last 12 years except when the AC is on. In summer I put it on "bypass" mode to cool the house.
The difference is very noticeable; if I enter another Portuguese house even I can almost always smell the odor our house used to have, a lingering mildew.
But the people living in there are used to it and tell me there is no smell.

For those who don't know about this device;
Commonly installed in other countries, a heat recovery ventilation system pulls air from your house and uses it to heat air from outside, which is routed into the house; effectively changing the air on a continuous basis without much heat loss. They filter the air too of course, so it helps during allergy season.

We also have underfloor heating, a big job to install but I recommend it to anyone building a new house or doing a full renovation.

Alan PT

The mouldy backs has been happening to pretty new Ikea furniture, but I did wonder whether the manufacturing process for the hardboard backs left them with excess moisture, or whether the mould liked the glue used in them. We mostly took them off now anyway, since they are mostly decorative and there is better airflow without them on

Good tip on the moisture meter though, I'll check that out if we have further problems after we get the dehumidifier. We already have a few mini air humidity sensors to monitor the general levels in rooms.

My OH has asthma and really suffered in our last apartment, she has definitely been a lot healthier in this place, even with some of the remaining problems. Our builder had never heard of HRV's before, but liked the idea so much he installed it in the other house he was building at the time

We did look at underfloor heating too but the install cost was a bit more than we could tolerate at the time!

liveaboard

It depends on the piece, but be careful; the backs are often important to prevent diagonal collapse.

coleio

What is the construction of your building? is it traditional "stones" with exposed lime render internal and external? After several years we found that having walls rendered in the traditional material allowed any moisture to distribute it's self over the wall and evaporate so we had no more damp patches/mould behind furniture - it seems to become a "dynamic equilibrium" with the wall render containing the similar humidity to the air in the room. The "damp meters" we tried were very random - the supplier explanation was - they measure moisture by passing a current tween the two spikes when pushed into something and clean water does not conduct electricity it needs dissolves salts to do that.

Alan PT

Not sure if you were asking me or liveaboard, our place is a new build so it has cavity walls with that exciting new innovation in Portuguese building, insulation Our walls are fine, it's more the general humidity level. Better ventilation helps remove the moisture we generate inside the house, but when the humidity level outside is frequently very high as well, there's a limit to what it can achieve

Meanwhile, my dehumidifier order has been randomly cancelled by the supplier, 4 days after I placed it, so I am enquiring with them what exactly they are playing at!

Alan PT

Ah yes, we did discover that the back is a rather integral piece of the structure in a Billy bookcase! Not a problem with some of the other pieces

Fortunately where we have the bookcases, the sideways wobbliness isn't an issue as they are supported by the wall at the end, otherwise I would have had to bodge some kind of cross brace