Horazontal runs for vented water heater.

Did an inspection with 2 draft induced water heaters, both with pvc vnet pipe. One was pretty standard. The other was ran around the basement with a main run going up then sideways out of the basement to the outside.
The entire horizontal run was around 20 to 30 ft with a couple of 90 bends.
Is there a limit to horizontal runs? It was really no differnent then some of the furnace installs I have seen but this was a first for a water heater. If seemed to be working just fine.

The manufacture of the water heater specifies the maximum length and number of 90s for the pipe size used.

Looks like the specific model allows runs up to 100 feet. Also allows up to 3 90 degree
Ruud Power vent
Should be good. First one I saw with this application.