Reducing humidity with a DIY moisture absorber

As you can see in this picture, the relative humidity in our place was very high during the winter monsoon. I do not know if it really was 99%, but it was high enough to give trouble drying our laundry, which makes all clothes stink. That is a small problem compared to what the high humidiy does to our digital cameras: if the fungus that makes clothes smell gets on the CCD or inside the lens, they wil be permanently damaged.

There is electrical equipment for reducing humidity, but a moisture absorber as descibed here does a decent job by using the natural properties of Silica gel.

How to make it

Parts needed

1. Plastic box with lid 80 x 120 x 50 mm (box 1)
2. Plastic box 80 x 120 x 80 mm. Box 1 should fit in the top of this box.
3. Silica gel (we used about 200 ml)
4. A mesh 80 x 120 mm, big enough to cover the bottom of the plastic box.

Step 1 - Prepare the lid

Heat up a nail and use it to melt about 16 holes in the lid.

heat up a nail

Melt holes in the lid

Step 2 - Prepare Box One

The inner box needs around 16 holes in the bottom, we also put a mesh inside to keep the silica from falling through the holes.

 Melt holes in the bottom

 Cut the mesh so it fits on the bottom of the box

Put the mesh inside the box

 Step 3 - Put a thick layer of silica gel in the box

Put silica gel in the box

 Put a thick layer of silica gel in the box

Close the box with the punctured lid

Step 4 -  Completing the moisture absorber

 Put box 1 into the higher box [1/3]

 Put box 1 into the higher box [2/3]

 Put box 1 into the higher box [3/3]

Appendix - Using the Moisture Absorber

Using it is pretty easy. Take a 15-liter box put all your gear in, together with the moisture absorber:

No photo, but: Don't forget to close the lid...

It works, look at these measurements:

 Humidity measurement in the store room

 Humidity measurement inside the box with absorber in the store room

Relative humidity went down from 84% to 45%, that's far above our expectations.

Drying the silica gel (and re-using it) is easy. I'll show that later.