>> yes it is zigzagged like that for now until I put a T splitter in so I can vent 2 dryers.
You might be better off just running separate ducts. I researched the "2 dryers / 1 vent" option for my own machines, and quickly decided it would be easier, safer, and cheaper to just run a second vent through the wall.
With two machines on a Tee (or better at least, a Wye), some amount of air is always going to be blowing backward through your other machine(s) instead of out the vent. This means you are pushing lint and humidity into the exhaust and blower assemblies of your machines, which is obviously not good for safety or longevity. (It's especially bad for gas dryers, as you create a path for combustion gasses to be blown back into the living space.)
The obvious solution to this is to install check valves... but the typical "draft stopper" style are prone to collecting lint, and may be a code violation to install in this way. There is a different style for multi-unit apartment buildings and the like, but they become more costly. You also would need to cut a larger hole in the wall and use a larger exhaust vent and pipework after the join, as a 4" vent is only suitable for a single dryer. And there's no way any of us would only use just one dryer at a time if you had multiples hooked up!
To me, cutting another hole for a second dedicated 4" vent made the most sense, and it's much easier to stay safe and compliant with the codes that way.
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