Update:
Today I finally got around to adding a fan to my radiation shield. The temperatures were not too far off a local Met Office site, however during the peak sunshine hours of the day, the temperature can really shoot up. So a fan was needed to assist with airflow within the shield.
I popped my designing head on and decided to fit a PC fan that was powered via solar. Not only to ease with access to the mains, but to provide a little more energy conservancy (even though the consumption would of been minimal!)
I bought a Solar powered pond pump off Amazon for around £7, with the intentions to use the solar power for the fan (45p from eBay) during peak sunlight. The output of the solar panel is 7v, meaning the fan has plenty of speed for purpose.
Have been testing it this afternoon and the results have been instant, temperatures have been around 1-1.5°C lower than before, which made me realise how important this feature really is! Today was a partly cloudy day, however the fan was constantly running, and finally powered down around 6.30pm this evening as the sun turned to the west.
This is one of my favourite editions thus far and relatively cheap!