Dehumidifier for the storage container at Puusepäntie

Suomeksi

Moisture accumulates in the Puusepäntie storage container, which has been made from a shipping container. Especially in cold weather, condensing water collects on the container's ceiling and drips down. This situation is unfavorable for the items stored inside the container. We decided to install an indoor air dehumidifier in the storage container. We acquired a Recusorb DST DS 010B dehumidifier, which draws indoor air in through a single intake, blows warm and humid air outdoors, and returns dry air into the container. To install the dehumidifier, a hole had to be made in the container wall for the dryer’s 75 mm exhaust pipe.

We determined the location of the dehumidifier in the rear section of the storage container, about four meters from the back wall. This way, the exhaust pipe hole would not be positioned facing the wall of the welding container adjacent to the storage container. The dehumidifier itself is installed on top of a platform, so the bottom edge of the exhaust pipe opening is 75 cm above the container floor level. We marked the spot for the opening on the wall, drilled a pilot hole there, and drew a 75x75 mm square around the spot on the outside of the container wall. Using an angle grinder, we cut a 75x75 mm opening in the wall. The opening was temporarily protected with duct tape.

A 75 mm diameter steel pipe will be fitted into this square opening, onto which a 150 x 150 mm square-shaped adaptor, or collar, will be welded to secure the pipe to the opening. The collar is attached at a slight angle, so the end of the pipe points downward. The end of the pipe is cut at an angle to form a lip, preventing rainwater from entering the container through the pipe. Before welding the collar, it is shaped to match the profile of the container wall.

Photo: Ari Aho

To make the exhaust air pipe, a 76 mm diameter, 500 mm long steel pipe was purchased from Motonet. A 150 x 150 mm sheet was cut from 2 mm thick steel plate to serve as the exhaust pipe collar. A circle matching the diameter of the steel pipe was drawn in the centre of the sheet for the pipe opening. Four adjacent holes were drilled along the curve of the circle, which were then joined to form a single opening. The round hole was then cut out of the sheet with a jigsaw. The hole was made slightly larger so the steel pipe could be inserted through it at an angle relative to the sheet. The edge of the hole was filed smooth.

Photo: Erkki Rossi

We visited the Finnish Aviation Museum to use the bending machine to shape the collar of the dehumidifier’s exhaust pipe to match the container wall’s corrugated profile. At the same time, holes were made in the corners of the collar plate for the fastening screws. Corresponding holes for the collar’s fastening screws were drilled into the container wall, and threads were cut into them. Now the collar was ready to be welded at a slight angle onto the exhaust pipe of the dehumidifier. Once the collar was welded, the pipe was fitted into the container opening. It was found that the collar needed a bit of adjustment to ensure it pressed tightly enough against the container wall profile.

With the exhaust pipe provisionally in place, the cut points for the pipe’s inner and outer sides were determined. Marks were drawn at the cut points, and the pipe was then cut to its final length according to these markings. The external end of the pipe was cut at an angle to form a lip that protects against rain.

To prevent small birds or mammals from entering the pipe, a protective mesh made from plastic-coated metal was fastened to the outside end of the pipe. The mesh was fixed to the outer edge of the pipe with two-component Plastik-Padding compound. Once the compound had dried, the attachment area of the mesh was sanded smooth.

The surface of the finished pipe was lightly sanded, after which it was treated with Isotrol lacquer to protect it from rust. The intention was to paint the pipe with the same blue paint which we had used on the container's surface. However, the paint had run out, so the exhaust pipe was painted with yellow Isoquard Pansar paint. The colours of Ukraine are now visible in our yard.

The dehumidifier’s exhaust air pipe was finally attached to the wall of the storage container by its collar using four screws. Repair compound, normally used for patching metal roofs, was placed between the collar and the wall. This ensured the contact surface between the collar and the container wall was watertight.

Now, the dehumidifier inside the storage container could be connected to the end of the exhaust pipe passing through the container wall and put into operation. Time will tell whether the existing dehumidifier is effective enough to remove moisture from the indoor air of our storage container and thus protect the stored items from spoilage.

Photos: Lassi karivalo, unless otherwise mentioned

Translation to English: Erja Reinikainen