I have been building an extra-dimensional space which I can connect to with portals. With these portals, I can cut down on the shipping rates and times. So I have made a global trading company of "zombies" that move every good imaginable all over the globe. Now that my trade company is set up and running,I find myself with some free time. But I fear that my extra-dimensional space may be taken over by someone else if I leave. So I want to make a temperate rain-forest inside my extra-dimensional space to dwell in. For this, I have made 8 teardrop shaped halls. They are connected to each other at the points and each to its neighbour forming kind of a wheel. There is normal earth gravity in the halls pointing perpendicular to the wheel. since it is extra-dimensional space that means that there is no outside.
Each hall is 5km from tip to bulb. The bulb is 1.2km high and 3.6km wide. And has a volume of 6km3. The lower half i have filled with fertile sediment and channels/ponds of water. I have placed lighting in the roof providing 9GW of power/light for 12 hours a day(24h). The ceiling is highly textured and a perfectly diffuse reflector. It has a set surface temperature of 1°C that dous not change in temperature.
Will these settings allow for a temperate rain-forest biome?
If they don't, then what do I need to change?
Will most "rain" come from clouds or condensation upon the ceiling falling down?
Alaback's definition of a temperate rain-forest. Annual precipitation over 140 cm (55 in) (KJ) Mean annual temperature is between 4 and 12 °C (39 and 54 °F).