Automated observatory cooling

[Peje]

My obsy (using the term loosely) is basically a large shed I built last year which has a mostly perspex roof, it houses all of my equipment other than the mount as it's on a pier outside. Over the summer months it gets insanely hot and in winter it stays a touch above ambient causing the odd drip and also meaning I need to let the telescope cool down before use.

A couple of weeks ago I started adding 4" round vents to the walls to help the shed stay closer to ambient, this seemed to work pretty well but there was room for improvement. A friend mentioned adding some bathroom style extractors which seemed like a good start, just before these arrived I had the idea to utilise PoE (power over ethernet) to drive some 12v fans since this would mean I could control them remotely via the web-managed poe switch. Installed the setup last night and it all worked perfectly. Yes it's a bit crude but 2 of these fans pushing out 3 cubic metrics per minute should make a big improvement over normal convection, it's worth noting that all other (6) vents are located around 20" from the ground to aim for cooler air being drawn in.

Today on lunch I decided to have a bash at accessing the switch via telnet, this worked surprisingly well and within a few mins I knocked up a couple of scripts that let me enable & disable the PoE port from CLI on a raspberry pi. I have another raspberry pi in the shed with a usb temperature sensor connected so in theory I could automate the cooling but for now I'm just going to leave it as manual.

#!/bin/bash

echo "open 192.168.1.90"
sleep 1
echo "enable"
sleep 1
echo "configure terminal"
sleep 1
echo "poe enable fe1/10"
sleep 1

I just created a second script to pipe this to telnet and away it goes Next thing will be to replace these two open vents with the ones with flappy louvres.

Thanks for looking! Pete.

[redtail]

I have installed fans similar to yours but run them of a solar panel. 

[Peje]

22 hours ago, redtail said:

I have installed fans similar to yours but run them of a solar panel. 

Now that's a fantastic idea