Why?
I see nothing but problems.
Slows down all the other customer going into the bay. They have to wait longer just to wash the car.
When I'm busy and I see customers vacuuming in front of the bays at my washes and no one in the bays washing I wonder how much money I lose out on when customer leave without being able to wash their cars.
Last wash I built I put all the vacs on the perimeter of the lot leaving a clean shot into the bays.
Do I lose vac income, probably somewhat but having the bays open more than makes up for it.
Also having your old vacs in a wet enviroment that some punk can spray the wand into just doesn't seem smart.
Tripping hazard having the vac hose on the wet floor.
I would think it would be quite easy. The vac probably has a mercury relay. If it is 24V, just run a wire to the selection switch. If it is 120V, swap out to a 24V. That being said, I wouldn't do it. The main reason being that the hose would almost always be wet and also could have pretty much anything under the sun on it, to be dragged into the vehicle. All of this will be your fault as well.
I would think it would be quite easy. The vac probably has a mercury relay. If it is 24V, just run a wire to the selection switch. If it is 120V, swap out to a 24V. That being said, I wouldn't do it. The main reason being that the hose would almost always be wet and also could have pretty much anything under the sun on it, to be dragged into the vehicle. All of this will be your fault as well.
I thought about this to, then quickly dismissed it for a reason stated earlier. Dragging the hose across a wet, and more than likely dirty/muddy bay floor will drag the dirt/mud into the vehicle. I think customers would get quite upset and your vac use would decline.