From what I can see all of the nozzles presented have a round opening. Can someone explain why there is no long flat option. Seems like if the round nozzle was flattened out (more like a vac nozzle) it would have a more squeegee-like effect?? Maybe i'm wrong here but we're looking at installing one this spring so thought it worthy of discussion. I'm sure there must be an explaination. Can someone help me understand?
I can’t explain the science/physics behind it, but I have seen and used both kinds (not at my own wash) and the cone shape moves water off the car much better and faster.
You have to move in slow, straight and steady rows to get the best effect from the flat nozzles - not to mention they have to be held much closer to the car, and you haven to lean over the hood to moand bend over to get down to the bottom of the sides. It’s just awkward.
With the cone shape, you can oscillate your hand and create a sweeping effect to push the water off the car and it is more efficient and effective. You can also hold the nozzle much further away since there is a more concentrated force of air coming out of the smaller round opening. You can move the air right across the hoods and roofs, and straight down the sides without having to hold the nozzle in a position or getting in a awkward position.
Might not be the best comparison, but most tunnel and IBA blower shapes have moved away from the long and narrow shape to cone shapes - with a few exceptions like the elephant ear and stripper type designs.
That is just my opinion from trying both types.