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"dry box" for drying clothes in humid weather Answered

Hi all,

I'm thinking of building something helping me to dry my laundry in the amazingly wet weather that I'm getting in the place I live now.

I searched instructables for a while, but did not find anything that really applies. This might be due to the fact that I'm both new to instructables, and not a native English speaker. I might be using the wrong keywords.

So I live in a very humid and foggy place, and it's winter now. When I hang my clothes out to dry, the process takes ages. Sometimes I think it might be working backwards: the clothes become wetter. Also, an unpleasant byproduct is that my clothes become smelly, despite they are clean.

Sometimes, as a last resort, I hang my clothes inside the house. But my house is very small, and I do not really have a place for the clothes hanger. Plus, the house gets very humid and I am afraid I'm going to get mold.

On the other hand, I have a rather large balcony, with a lot of place for the clothes hanger.

Of course I could buy a clothes dryer. I actually use a coin-operated one for large items, such as bed sheets and large towels. But I'd rather not use a tumble dryer for my clothes.

However I recently learned about heat recovery ventilation for houses, and I started wondering whether the same concept could be used to build a small-ish enclosure (a box) where air is kept warmer and dyer than outside, possibily in a controlled manner.

Also, it would be very nice to get energy from the sun. Surely the walls of this box could be transparent, or black, to create some kind of greenhouse effect. Then I need a fan, to have the air circulating. The air could go through a heat recovery unit. This could probably solar-powered.

On the other hand, I am not sure that solar panels would be helpful for heating the inside of the box by night (energy should be of course stored, but I do not think that would be enough).

I see that something similar to what I'm thinking about is already on sale e.g. on amazon. These are called "portable clothes dryers", but they do not seem really optimized. They look like a combination of a hair dryer, a clothes rack and a tent. I do not think there is a real heat exchanger, or humidity control...Plus, they do not seem really safe, especially if operated outdoors.

Can someone give me some advice, e.g. pointing me to projects that use similar ideas possibly for different purposes?

Thanks a lot




1 year ago

I love to tinker with thinks that should not be tinkered with, and I had a very similar problem.
For me it was living in a flat that had one half under ground, so limited ventilation of dry air possible.
And the weather was too bad for drying all my work clothes most of the time.

I found a clothes dryer with condenser.
Unlike the cheap standard ones that just blow out all humid and hot air these use two fans.
One blows the room air into the heated rum, the other blows fresh over one side of the evaporator plates.
The hot and humid air will then condense on the other side of the plate and can be drained off.
But you want to go at least one step further than just building something similar to add to your dryer I guess...

If you suffer from both long term wet weather and the need to dry a lot of clothes then using a portable split aircon system might be the way out.
Just to be clear: there are two types!
I don't mean those single tower ones with the axhaust pipe going out the window.
I do mean a real split system with seperate "indoor" and "outdoor" unit.
Here is how I currently use it: To cool my bedroom...
Here is how I use it the cold winter times:
The indoor part is in my laundry and the outdoor unit sits in the hallway with the door closed as much as possible.
All clothes are on a rack right in the outgoing airstream of the indoor unit.
I use the dehumidifying setting on the aircon...
Within about an hour my clothes are dry, although on a very cold day I have to assist with a little heater to speed things up.
And the produce heat from the unit is not wasted as it warms my house while drying my clothes.
Being a quite small device my aircon does not use more than 1000W under full load.
Best of all is that the humidity in the house is kept low to prevent mould building up in cold spots.
Keep in mind though that you would need to elevate the oudoor unit so you can use a bucket or so to catch the water.
No point drying your laundry if you soak your carpet as a result ;)


1 year ago

Many years ago, I converted a "drying room" in my climbing club's facility in very wet North Wales from a system that took a pound an hour to run, and not dry clothes, into one that cost less than 0.1 pounds per hour - and gave dry clothes. I bought a BIG industrial dehumidifer, capable of over 3 gallons per hour removal rates, put it one end of the room, then fitted large ceiling fans and blowers to really stir the air up. So, yes, its very feasible.


1 year ago

Drying anything requires that the water molecules are excited to make them 'jump' away from the material, a breeze then blows those molecules away.
We often add heat because this energises the water molecules to' jump' higher and makes them easier to blow away.

Something like the image attached (click for bigger view) would work.

BUT for cheapness omit the dehumidifier and just vent the moist air outside replacing it with air flow from the house.

A modest heat is all that is required, IF you put wet clothes over a heat source then you MUST put a shield between the clothes and that heat source + sensible protection against overheating.

NEVER leave such an apparatus unattended.


For removing moisture, the most important factors are airflow and exposed surface area.Commercial tumble dryers are actually terribly inefficient because they are trying to fit everything in a really small space. The more efficient way to dry clothes is hanging on a line in a strong breeze. But this does depend some on the humidity and wind speed outside.

The first thing to consider is ways that you might be able to get more of the water out before hanging them up. In the old days, they used a wringer to squeeze more of the water out before hanging them up. You can also use a press like the kind they use on a janitors mop bucket. https://www.google.com/shopping/product/1100585909...


Reply 1 year ago

Hi Jason,
and thanks for your input. The link you attached seems to be broken, but I think I know what you're referring to.
However I guess that in modern washing machine the "wringing" part is mostly done by the final centrifugal cycle.
I'm not sure I'd want to have my clothes go through more than that amount of wringing.

I was thinking of something along the lines of this object
However, as I mention, this kind of object seems to be basically a closeted clothes hanger plus a hairdrier.
I recently heard something about heat exchangers used for decreasing the humidity in houses while not giving up precious heat.
I thought that this could be applied on a smaller scale, to dry up clothes faster. I guess that this could be good also for "ironing" clothes, unlike what happens with tumble driers and wringers (I guess).
The only thing is that, as far as I understand, heat exchangers need a temperature difference of 10° C or so, and the outside temperature should not be too cold, otherwise the outgoing humidity would freeze and block the pipe.

DIY Hacks and How Tos
DIY Hacks and How Tos

Reply 1 year ago

Yeah. That product seems to be a glorified blow dryer in a closet. Have you considered using a low cost dehumidifier (maybe with a box fan to help circulate more air.)?