Why is my dehumidifier not lowering the humidity

[QuebecBagnet]

I have a meaco one so good brand, admittedly only the 12litre one but it’s meant to be able to suck up 12 litres a day. However it takes about 2 days for the tank to fill. Humidity always seems to be above 60% and it’s always running so probably costing me a fortune in electricity for not much benefit.

it’s kept downstairs, we don’t open the downstairs windows. It’s a 3 bed semi and downstairs there’s an open plan kitchen dining room, very small utility, hall and a living room. It’s not a big area. It will also be pulling in air from the landing and stairs I guess.

why does it not extract 12litres a day like it says it does? I should be emptying the tank 6 times a day!

I’ve just moved it up to DD’s mouldy bedroom and shut it in there to see how it gets on. Set it up an hour ago with an empty tank and humidity is 61% so see if it manages better in a single room.

I think the open plan set up is the reason. Dehumidifiers work best in an enclosed space. We do a room at a time, and make sure the doors stay closed.

You answered your own question in your post. You don't open the windows. You need to ventilate and not rely on the dehumidifier. It cannot cope with the constant moisture being added into the air from day to day living and reduce the overall humidity.

It won't work in such a wide area the way you want it too. You'll need a beast for the set up you describing. They work best in one room with the doors and windows shut. Open plan will be hard work for one.

My house is never ever below about 65% no matter what we do. It doesn’t matter how long the dehumidifier runs, in a small room with windows closed - still over 60. We dry the minimum inside, ventilate every morning, vac the windows, run the extractor fan and still always high. Some houses are just damp I guess.

I don't know if this is any help to you but we don't have a dehumidifier, we have nuaire piv ventilation system, it has made a big our house,
www.nuaire.co.uk/product-list-page/drimaster-eco-range

We used to do that. But then I read while running the dehumidifier you should have the windows shut because otherwise you’re just trying to dehumidify the outside air?

Sadly I think may be us. We vac the windows and open bedroom windows every day. House is just damp. But I still don’t understand why it doesn’t extract 12 litres a day even if the humidity doesn’t lower?

Thanks, did you fit it yourself or have it installed? If the latter did it cost a lot to have it installed and if the former was it easy to do? Does it cost a lot to run?

dehumidifiers work on cubic meter volume of air.

check the manual for what room volume your dehumidifier is made for.

in addition - the humidifier reduces humidity in the air.
there is no gas exchange which is important for air quality, especially if you use open flames (gas cooker, candles).
you need to open the windows (or have a mechanical air exchange system) for that.

60 is within the ideal humidity range, so probably not damp enough in the air to suck up lots of water.

we have nuaire piv ventilation system,

The problem with those is that they are blowing cold air from outside into your house.

We live in an open plan house with high ceilings and always have all the different room doors open, so it's like one massive room. Also have a Meaco 12L dehumidifer and it works brilliantly. I've set it to 55 and it fills up about once a day because we have washing hanging inside pretty much every day (the joys of potty training). Have you spoken to Meaco? This dehumidifer is actually a replacement because our first one did exactly what you described - nothing. They had me do a test where I put it in the en-suite with the door closed, had the shower run hot for 10 minutes, and then let the dehumidifer run for an hour. Absolutely nothing happened, not a drop inside of it. So they sent me a replacement and that one works great.

My husband fitted it himself , which was just a matter of cutting a hole in the ceiling, then we got a electrician to wire it up. Not a expensive job. I know few people now who have them and are happy with them.

I had decided to buy a Meaco 10 or 12 but can’t find it in stock or if it is they don’t deliver to NI. Does anyone recommend any other brand?

12l is the amount it will extract in perfect conditions, not in your average house.
It will be something like 30c and 90% Rh to get that output.
The colder the room is the less you get, it's all based on the dew point of the air and how far it is above the dehumidifier element.

Your house won't be humid enough to extract 12 litres a day. It probably only has around a 2 litre water container so you'd have to empty it 6 times a day which would mean that your house is virtually underwater. 60% is fine but a single domestic humidifier won't do a whole house on more than one floor

Also worth bearing in mind that cold air can be quite stagnant and warmer air moves around more. If there’s no heating on, it might be harder for the machine to do its job.

They work better in warm environments
also I thought 60% was ok

Thanks everyone. Will persevere with the ventilation upstairs and also the window vacuum (which is new). If that doesn’t help I’ll see about turning the heat up a degree.

I just bought this one, it's great

Inventor EVA ION PRO Wi-Fi 20L Dehumidifier

The model you chose will be fine for a single room but will not cope well in open plan layout. You should ventilate for a few hours before running dehumidifier and then for a couple of hours after too.

I don't think 60% is that bad.

We have the same brand and ours sits on the landing. Its only on in the day time but averages about 75% humidity at the moment. 2 bed terrace. We empty it about 1.5-2 times a day.

I window vac as well. I bloody hate it!

It has definitely made a massive difference to our house. I was fighting a losing battle against damp before.

I know they work best above 18 degrees. Are you cleaning out the filter as well?

You dont say whereabouts you live.
There is a HUGE difference in the average humidity in the south of England compared to the north of Scotland and this will greatly affect the 'norm' you can expect in your home, whether open plan or not.