I know of one major manufacturer that has published testing results on this subject. The worst performance was from an air maze design. There was not sufficient in and out flow to properly activate the moisture removal function. The next worst was a standard mesh element breather. The best option was a desiccant design that incorporates check valves such that any air expelled from the housing does not pass through the desiccant media. That is now our preferred breather on most pumps.
Thank you for your input JJPellin.
I have looked into desiccant design and they are good but more expensive.
Can you think of any good manufacturer of maze or mesh element type breather from your experience. I understand they are not as good but they are not as expensive.
Thank you once again.