Hard to picture what you're describing, but I think you can work with that. The warmth will help you germinate the seeds. Not sure what your temps will be like. It will depend on your lighting and room temp. You can probably grow two plants in that space and you will obviously have to keep them short. Post pics of your room if you can. Good Luck :thumbsup:

Also, make sure you don't put yourself in any kind of hazard with the water heater below electricity. I hope your heater is grounded. You may want to provide more details about your room so others can give you better advice to move forward or not.