The AC110 intake is 3/4", so you will need to use 3/4" PVC and 3/4"ID vinyl tubing.
Check out the link in my sig for more info.
That write up was done with an AC50, but its the same thing with the AC110. Just swap out the 1/2" PVC for 3/4" PVC.
Also, the braided vinyl tuning does not stretch the same.
I just used a 3/4" to 3/4" PVC coupler to connect from the "U" tube to the PVC pipe. But you could use vinyl tubing and hose clamps.