RetireJapan

Hi all, just wondering if anyone has good experience with dehumidifiers they can share?

I recently bought a place in the countryside and it's obvious to me that the ventilation fans that run 24 7 situated throughout the property haven't been sufficient to keep the humidity of the place low enough - hence some minor mold issues. Humidity has been running at around 60%.

I'd like to install some dehumidifiers to get the humidity down to around 50% and ideally have them running even when I'm in Tokyo. Unfortunately there aren't any drains in the key rooms.

Does anyone have any good ideas for setting up continuously working dehumidifiers without drilling holes to the outside? Keeping windows open isn't an option due to insects.

Also, there are no air-conditioning units - the property is in a year-round cool location, so not needed.

Size of the property is about 140sqm , 3LDK and two stories.

60% sounds pretty good to me...

We run our A/C to get down to 55-60%, but if we leave it off it goes back up to 80% or so

Dehumidifiers need to have their tanks emptied by hand, as in carry it over to the sink and dump the water out. I suppose a MacGyver type could rig one on a counter next to (or in?) a sink, but then it'd likely run 24/7 and I'd worry about overheating and possible fire.

Since the place is closed up when you're not there, an alternative might be to get the indoor air moving. Maybe a couple fans on a timer, run them a couple hours twice a day?

We do have a dehumidifier that does one room really well. I'm not sure how many units it would take for 140sq m and two stories.

Somebody in another thread recommended this one. It'll do 102m2 and there's an optional hose to dump the water into a drain.

fools_gold wrote: ↑Sun Aug 29, 2021 12:12 pm Somebody in another thread recommended this one. It'll do 102m2 and there's an optional hose to dump the water into a drain.

Thanks for linking to my original post. You saved me the trouble of trying to find it

I love this dehumidifier. I keep it running all the time and I only need to empty the tank about once per day. I don't use the hose attachment because that would only work in the laundry basin which is in a very confined area of my bathroom and probably wouldn't distribute the air as efficiently. Instead, I keep the dehumidifier in the hallway that connects the bedrooms to my living room/kitchen area.

I'm wondering why people are talking about ventilating their homes to decrease humidity? For example, when I turn on my kitchen exhaust fan it operates in a loop pushing the smoky air out and pulling fresh air in from the outside through a vent on the opposite side. I've noticed the humidity level jumps back up to 70% (or more) in my home after some time because that's actually how humid the air is outside.

Thanks for the added info.

I agree that extractor fans aren't a real effective way to remove moisture but conventional wisdom is that they help.

Personally I'd prefer to have an air source heat pump and - I have this in one of my places in London. Retrofitting would be exorbitant though.

We use these: https://lifeabroad.jp/html/blog/2019_bl ... fiers.html and put them anywhere there is poor air circulation. They need to be replaced fairly regularly but seem to work. Mold tends not to grow where the air circulates well so potentially using these in combination with leaving fans and air extractors permanently on may be your best solution short of installing a large dehumidifier that dumps the water outside.

A more eco-friendly option are these. https://item.rakuten.co.jp/nile/dem-csj-cs50m/

Can be reused to avoid throwing away plastic.

Seem to work, though I must admit my partner keeps tabs on these things.

Just hijacking the thread a little.
My aircon has a dehumidifier setting. Is this good/energy efficient? Or is it better to get a specialised dehumidifier separately? For reference my ac is a brand new 2021 Mitsubishi model.

It depends on the type of dehumidification your air conditioner uses.
『弱冷房除湿』just cools the air to remove the moisture
『再熱除湿』also cools the air, but then reheats it to the required temperature. This way uses more electricity.

I think newer units use the 『弱冷房除湿』method, but you'd have to check the manual or homepage to be sure.