Its better to suck or to blow ?

All boats remove the bilge air with blowers, assuming the engine room is semi tight, fresh air will come in from the engine room vents. Thats the way the USCG wants it. But your in Germany so ...

 

If you ask mega maid, you can go from suck to blow. Sucking is always more effective at removing something as something else has to fill in the void.

 

If you’re trying to remove harmful vapors like fuel vapors, it’s much better to suck them out. You have more control over where they go, and any leaks in the engine compartment will simply allow more air in, rather than letting vapors migrate into other parts of the boat.

 

What's better? The way that all manufacturers currently do it. Suck out the air. Sucking it out is better. It HAS to be sucked out to get the (possible) fumes that would settle low. Suggest you read up on air vs gas fumes and how a bilge is setup with fresh air intake and exhaust fans rather than trying to reinvent what has already been determined to work best by people smarter than me.

 

Suck the air out. If you suck the air in you run the risk of filling the ER with fumes.

 

Our 370 seems to have one pulling in outside air and one sucking out from bilge floor.

 

No, it does NOT create better ventilation by blowing air in. See the reason I posted above.

The exhaust hose HAS to sit low. See the reason I posted above.

You could ADD a blower... but the primary means still needs to be by sucking.

Regarding blowing in, though... THERE a good conversation could be had whether the finite amount of air being blown in by a blower is greater than what is drawn in by a running engine or two. I suspect the engine is more efficient.

Oh... yeah, got the Space Balls reference