Thermos Aquariums

[Richies^Ghost]

So here's an idea - why not build an aquarium like a thermos?

A thermos works by insulating air between two walls, preferrably walls that don't transfer heat well - this slows down the transfer process of heat/cold between the vessel and the external environment.

Heating or chilling aquariums is an important and expensive process - this process could be improved by using this technique. Doing so would be very practical with a plywood build, such as by placing styrofoam sheets between plywood sheets. The viewing window would be as normal, with considerations of glass thickness for the inner glass/acrylic piece, with an external piece placed a centermeter or so away from it - this peice wouldn't need to be thick, as it wouldn't be under pressure.

The important part seems to be sealing the two pieces to ensure air is trapped, and also that glass used is clear enough to prevent distortions. An interesting idea with this is the possibility of a magnifying effect, giving a more impressive viewing experience.

 

[kallmond]

The gas between the pieces of double paned insulated glass is not actually air, its usually argon, krypton, or xenon gas. DIY Argon injection seems pretty complex, not to mention finding a tank of argon gas. Look at how many home-builds leak water. Imagine trying to seal pressurized argon gas between to plates of glass. Air itself between the panes is only an R value of 2. If you double the glass costs, it would take about a bajillion years before you saved the investment.

Alternatly, the ideal insulator would be a perfect vaccuum between the panes, although that would already strain the glass inward, and then adding water pressure behind that may effect required thickness.

 

[knifegill]

Still, a plain unpressurized layer of air between the panes would insulate. I doubt it would need to be perfectly sealed, either, since there wouldn't be much circulation. I don't think you'd want to magnify the tank, though. It would be painful to look at. Simple way to test it is to make two setups side by side. In one, a tank is set up normally. The other, a small tank inside a slightly larger tank that is about the same size as the other setup. Close up the top of the gap with something like plastic/acrylic pieces as well as you can, and see which tank heater works harder.

For the plywood idea, you could just make a standard DIY plywood tank, wrap it with styrofoam, and add more panels. That way the inner tank is doing all the structural work and the foam isn't under any pressure.

 

[Conner]

The gas between the pieces of double paned insulated glass is not actually air, its usually argon, krypton, or xenon gas. DIY Argon injection seems pretty complex, not to mention finding a tank of argon gas. Look at how many home-builds leak water. Imagine trying to seal pressurized argon gas between to plates of glass. Air itself between the panes is only an R value of 2. If you double the glass costs, it would take about a bajillion years before you saved the investment.

Alternatly, the ideal insulator would be a perfect vaccuum between the panes, although that would already strain the glass inward, and then adding water pressure behind that may effect required thickness.

Actually argon isn't that hard to find. Most welding supply companies carry it in various sizes, as well as nitrogen and hydrogen.

Making the void between the glass panes gas tight could be difficult to do in a cost effective manner, as well as requiring the glass to be sturdier due to putting it under pressure.

It is possible to do this, maybe using a fiberglassed frame around the two pieces of glass, silicone them in place, and install some kind of metal check valve through the wood that you could add gas through. Even if it isn't complete pressurized, even adding gas up to just above normal pressure would probably add some kind of insulating value, although the costs incurred probably wouldn't be worth it.