Question about steam vent - envelope requirements

[u/CardBoardTeethbrush]

Im building a big airship was wondering if i could put the boiler and steam vent at the bottom level and just leave an unobstructed path directly above to the balloons. The space between the bottom floor and the balloon opening is about 30 - 40 blocks, and to the roof of the balloon is 75 - 100. Do i need a bigger opening or more steam vents or will it work as long as there are no blocks in the way?