97 Tropical Holding Tank Roof Vents

[sunnysouth]

Hi fellow RV'rs

My 97 Tropical (model 236L) has what appears to be two holding tank roof vents. I'm assuming one for each of the holding tanks (black & gray).
I'm curious however as to why one of the roof vents seems to run underneath the floor somewhere and crosses to the opposite side of the motorhome in the area of the wardrobe - then up through the roof.

I'm mostly curious as to why they wouldn't simply run both vents straight up from the holding tanks and through the roof rather than routing one of them clear across the motorhome to the opposite side which would seem to me to cause possible venting problems (horizontal slope rather than straight vertical).

I know some manufactures tie the black and gray water holding tanks into one vent.

Hope someone out there has knowledge of how National sets up their holding tank vents so I can get a clearer idea of my venting.
My reason is that I want to add Camco Cyclone Vent Caps to my vents and I need to know if I need one or two.

Thanks all.

[Theberrys]

Your Grey Water Tank is probably run under the floor to the passenger’s side for pre plumed washer hookup on that side. You can pull the drawers out of the wardrobe and may find the plumbing behind them.

Dick

[sunnysouth]

Thanks Dick
Actually I did in fact find the plumbing this spring for the washer where you indicated (the previous owner didn't winterize properly and one of the water pipes was cracked and sprang a leak the first time I added water to the system).
I didn't however see any signs of a washer drain pipe stand or connection to the vent system for the grey water tank, but I'll have to take another look - it could be in the wardrobe itself instead of behind the drawers which is where I found the water pipes.

[Vegasdan]

I will be there.