Insulation using Plastic Sheets to create a double pane aquarium

[alienara2]

Saw an old post talking about using acrylic sheets to create the same effect as a double glazed window on 3 sides of an aquarium. Acrylic seems really expensive so I was wondering if Plastic sheets were a viable replacement.

My thoughts were to cut up plastic sheets to match the length of the aquarium for the back glass and sides, and use heavy duty double sided tape to tape the plastic sheets to the aquarium.  Since the aquarium has plastic surrounds, there would naturally be a gap between the aquarium glass and plastic sheet.

Thoughts?

[alanmin4304]

You may have a problem with condensation between the layers which could look a bit rough.

[Devrens]

You may have a problem with condensation between the layers which could look a bit rough.

Would be impossible to clean as well. Just a completely off the wall thought: what if you found a crystal clear epoxy and managed to (miraculously) attach the pane without any air bubbles? Would that theoretically work?

[alienara2]

With the double pane, isn't the theory to use air as an insulation? If you used the epoxy that has no air bubbles, then that doesn't really work... I think. 

Thanks for the thoughts guys. Good to have some discussion here. 

Would this idea then work if I totally sealed each area up? In that way, theoretically, because there is no exchange between the air between the glass and plastic sheet, the condensation should only appear on the outer side of the plastic sheet. 

[alanmin4304]

I could be wrong but I understood that double glazed windows had a vacuum between the glass to avoid convection currents of air.

[calculator]

To the best of my understanding double/tripple paned windows are just layers of glass with air in-between them.  Air is a relatively bad conductor of heat, so as the air is trapped in the glass and can not form convection currents, or blow away it is a good form of insulation.

In the same way as a jumper is good at keeping you warm, not because the wool is a good insulator (although it is not bad) it is the air that is trapped between the fibres.

Edited November 21, 2015 by calculator

[JaSa]

@ calculator:

 

Yes - but air still transfers heat energy via convection. In a situation where there is only a small gap (for example a double galzed window) and you can't use big layers of insulation to slow down heat transfer. Your only option is to go the oposit way - take everything away that transfers heat, even the air. That's why they use vaccuum in thermos jugs and not wool

 

Cheers,
JaSa

[alanmin4304]

There is a similar problem with double glazing to cut down on noise transfer. The noise causes one pain to vibrate and the next pain picks up a sympathetic vibration. The way to make the double glazing work to avoid noise transfer is to have two pains of different thickness and have one at a slight angle to the other. There is actually a thin layer of still air next to a single pain of glass and that can act as a heat insulator if that layer is protected by the likes of a curtain close to the glass.

[David R]

IMO I suspect that unless you have a huge tank in a very cold space that you'll save enough power to justify the ugliness and the effort. Use polystyrene to insulate the back (and sides if you don't view the tank through them) and leave the front open.  And before you start use Hovmollers heatloss calculator spreadsheet to work out what your potential gains are...

[fishyNZ]

Based on the calculator, covering all tank sides minus the front with 25mm polystyrene would result to a 60% reduction in heat loss, compared to no insulation (on all sides).  This applies to any tank size.  So like David R said, the amount of effort may not be worth it.