I think it would be enough for your mushrooms .... not too much else. I had shrooms and ricordea's under a 13 watt PC blue/white combo and they not only survived but grew as well - not very fast but they did grow!
I have 2x13 on my eclipse with no fans. All you have to do is just drill tons of holes in the lid or just take it clean off. Mine stays at about 80-82 degrees.