It's going to be functional rather than pretty (pretty just costs too much!), roughly 3mx2.5mx2m (L,H,W) which will give me space for 1000+ bottles. Got a local builder friend sorted who understands the need for insulation + mositure barriers etc. The space will come from partioning off the dining room (thanks to my very understanding wife), so no external walls which will help. Racking is sorted, I've ordered some powder coated stainless steel jobbies.
So onto the vexed question of temperature control, I've discounted a proper refrigeration unit, just too pricey, so am looking at a small standard split system. I'll try the wick / bucket thing to try and keep humidity up, and may look at getting a cheap evap cooler if this doesn't do the job. I'm hoping to to get a reasonably stable 16 degrees, it would be great to get some opinions on;
Is anyone aware of any split systems that actually go down to 16,
Any thoughts on running 24x7 as opposed to using a timer switch,
Has anyone used a sparky to modify the thermostat to get a lower temp (and then used a timer swtich to stop it freezing up)?
Any recommednations as to which units suck the least ammount of moisture (best I have found so far is the small fuji at 1l per hour)
I've heard that non inverters are better, these are getting hard to find - is there a big difference?
Lastly - I've had some recommend getting the waste water pipe from the aircon to be routed into a container in the cellar to help with humidity, but been told by other engineers this will fill over a bucket a day and I'll be forever emptying it - anyone done this?
Appreciate that this has been covered before, but it's been a few months since the last discussion so it would be great to hear if any views have changed, any personal experiences etc.
Cheers - Nick
PS - There will be a couple of large Vintec unuts up for sale in 6 weeks or so if any Brissy forumites are keen
I have asked a few cellar specialists' about cooling gear both new and second hand but nothing that reasonable has popped up yet. 
to get purpose built wooden racking from cellarwine and had them installed.
I am also fortunate (again) that my father in law is a builder and cabinet maker and he has promised to help with the fitout - once he finishes the rest of the house! I also have a large felled Red Gum tree on our property that I can mill for the shelving and lining if I go timber.
). The biggest risk is uplift (tank floating) and if there is any chance of the water table being near the bottom of the cellar or higher or water infiltration around the cellar then there could be significant issues in the cellar "popping" and severely damaging your house slab. I could not see much of a risk in this case, but beefed up the slab over the cellar significantly anyway, just in case. If you have a higher risk situation than mine, it is solvable, but as your engineer has suggested would involve either sumps or drains to prevent water build up around the tank. 
