I have ordered a new trailer (or float as we call them here in Australia) and the manufacturer has said that if I can get the vents I want in from the USA in time, then they will install them for me.

In Australia the only vents they seem to put in trailers are pop-up vents facing forwards (not two way) which to me brings in a large gust of air, bugs and rain.  I've been looking at what is available in the USA and you have a great variety.  The ones I think I want are the two-way pop up vents ... a couple of examples of what I mean:

http://www.austinhardware.com/product.asp?dept%5Fid=210&pf%5Fid=1678

http://www.horsetraileraccessorystore.com/trailervents.htm

The concern I have (since I've never seen them "in the flesh") is the handle to swap the vent sides over and how much it hangs down into the horse stall?  We usually situate vents over the horses' shoulder area but if the handle hangs down 1 1/4" then is it going to be a problem with a difficult horse and head clearance?

I'd love any opinions and thoughts on this.  I've looked at as many web sites as I can to see how you have them situated in the USA and it seems for slant loads (mine is a straight load) you have them over the stall area, but not near where their heads are.  I have a horse that gets very hot in his current trailer and I'm trying to make sure I get as much ventilation as possible around his head without causing gale force winds when travelling at high speeds for the new one!

Thanks!

I had 4 pop-up 2 way vents installed in my trailer when I ordered it and they don't bother the horses at all.  My trailer is very tall at 7'9", but I've had drafts and warmbloods in it many times.   I had  4 installed in my 2H since I live in South Fla.

http://www.horsetraileraccessorystore.com/trailervents.htm

The concern I have (since I've never seen them "in the flesh") is the handle to swap the vent sides over and how much it hangs down into the horse stall?  We usually situate vents over the horses' shoulder area but if the handle hangs down 1 1/4" then is it going to be a problem with a difficult horse and head clearance?

This unit is similar to what is in my trailer.  The 1 1/4  is about the same as the ribs supporting the roof metal.  If you have the roof insulated flush with the ribs, then the protrusion is less than 1/4 inch.

Not a significant factor in my experiance.  If you place the vents over the horse's head while standing, I would think that if he reared, his head would hit the ceiling towards his rear.  Not directly over his head, where the vent handle is.

Thanks for your prompt replies!

It sounds like if I have the vent open on "exhaust" most of the time then the handle wont be in the way, even if I do have it over their heads.  Good point hosspuller about the ribs supporting the roof, I hadn't thought about that (one of the problems of not being able to see them installed it is hard to get the concept of how they work!).

My current trailer is 7'1" ... new trailer is going to be 7'3" ... I do travel large warmbloods most of the time, but I've never had a rearer in the float (only ever seen a horse hit the roof on loading, not once in there) ... I just want to be safe for the future if I do have a difficult horse ... then again ... if they are going to hurt themselves they'll do it on the safest thing anyway!

Maybe Australian trailer manufacturers might catch on to the idea of two-way vents!