Tuesday 28 February 2012

Air conditioning

Another winter-sensitive part is the heat exchanger of air conditioning unit on the end of the RF container. This is completely exposed to the elements and there was a large potential of ice and snow building up and causing problems.
The the heat exchanger of the air conditioning unit is located at the end of the RF-container. 
We asked around a bit, and heard of this type of a snow shield specifically designed to keep snow and ice out of air conditioners, without interfering too much with the primary function of dissipating heat.
Snow shield
Here is a picture of the snow shield installed on the RF container:
The snow shield, GPS antenna, and the already slightly weathered hawk owl's nest box. 

Monday 20 February 2012


Each HBA tile is covered with a UV-resistant polyurethane cover. This secures the white polystyrene lids and provides protection against precipitation. In order to connect the cover to the timber frames, O-rings are connected from the cover edge down to S-hooks that attach to the screws in the timber. However in order to attach the covers to the O-rings, special rods called "staafjes" (Dutch for "little staves") are inserted into the folded cover edge.

Left: The tool used to put a hole into the cover rim.
Right: detail of the tool and a freshly made hole.

Another hole is cut into the cover edge.

The rods are then inserted into the cover edge using long-nose pliers, with the O-ring locked in to the cover edge.

Normally an HBA tile has 8 of these staafjes around the edge. However, in order to secure edge tiles, ASTRON recommend that an additional set of interleaved staafjes are added. However, due to the very exposed nature of the KAIRA HBA tiles, and the horrendous Arctic conditions expected on the site, this total is doubled again.

During the build, we had already added some additional staafjes, however the work has now been completed.

Wednesday 15 February 2012

Snow fence - Part 2

Below you can see the finished snow fence under the support structure. We also used plastic snow fencing material on the other edges for the antenna groups. Luckily this material was available in other colors than bright orange.

Ready for winter

Friday 10 February 2012

Snow fence - Part 1

With winter already half through, we will go through several preparations that we did at the end of 2011 at KAIRA for the approaching winter. 

First of all, in order to prevent snow from blowing underneath the tiles, we converted the palettes used for transporting the HBA tiles into a snow fence. In the summer the snow fence will also prevent reindeer from walking under the tiles.

HBA palettes being converted into a snow fence. 

A small access door to allow