Unregulated summer temps and my BCI

[chairman]

A first step for you could be to place the enclosure directly on the ground. It will be cooler down there than at any other level in the house.

Your plan with the fan will probably not work. A fan can suck hot air out of the top of the cage but the cage will still be the same temperature as the room it is in. If the cage is getting hotter than the room then the fan might help.

Likewise, piling substrate won't really help. It is cooler underground but you can't really replicate that just by piling dirt in a cage. That and a T8 won't hold all that much dirt.

You will probably need to cool things off by circulating cool water through the cage. The basic idea is that you run a coil of hose under the substrate on the cool side of your cage and have a pump move water through the hose, creating a cool spot. (I don't think this approach will lower overall cage temps.) 1/4" hose will probably fit through the vents of the T8 without adjustment. They make solar powered pumps that you could use to move the water.

There are a lot of ways to cool the water. Use a cooler as the storage tank for the water and dump ice in there every couple days. Use a 10 or 20 gallon aquarium and a fan powered aquarium cooler. Use a genuine aquarium cooler (though these are expensive and may pull more current than your system allows). Keeping the storage tank in a mini fridge could work too (also may be too much of a power hog). Burying the storage tank, or keeping it in a crawl space, could work too.