For those of you who have a large amount of equipment that you want to store in a dehumidified environment and are balking at the cost of a commercially available large dehumidifier, here is what I have just done.
I bought an unserviceable two door, upright display fridge, removed all of the refridgerative equipment and then painted it as it was looking a bit used. Its storage capacity is approximately eight hundred litres. There are plenty of these units available on the web in various sizes and condition.
I then purchased a small dehumidifying unit and placed it inside the now storage cabinet. The dehumidifyer comes with an inbuilt humidistat so the only other purchase was a hygrometer. This dehumidifier is capable of dehumidifying a much larger area than what I have got it doing.
For anyone in Australia who wants all the contact details just send me a private message and I can post them for you.