How do we size a water pump for carpet cleaning in a high rise Bldg?

[AESMC]

A friend of mine is a carpet cleaner with a hose and pumping rig in his truck. He often gets requests to clean carpets in condo's several stories above ground. The question is: How high off the ground can he expect to be able to service his customers?

If we assume that:
1. the pump is mounted on the truck
2. the power source is limited to a 3/4 HP motor at 120 volts
3. electrical power is most convenient from a duplex receptacle within 50' of the truck
4. the water comes from a hose bib supplying city water at approximately 40 psi, within 50' of the truck, and fed to the truck with a 3/4 to 1" rubber hose
5. the output side of the pump is also a 1/2 to 3/4" rubber hose
6. Ground level is within a few feet of sea level
7. assuming a story of a building is 12-15'

What would be the maximum size pump he could use, and how many stories off the ground could he pump the water with out increasing the the hose or motor size?

 

[ChasBean1]

AESMC, missing from above is the necessary flow rate. Anyway what your man might need is a positive displacement pump such as a gear or piston style pump. He can probably find one that suits his need by doing a search for "positive displacement pump." Try, for example:

http://www.vikingpump.com

These pumps give data at 100 psig (about 18 stories) discharge pressure. With positive displacement pumps, however, he will have to think about the design of fluid delivery as well - you can't just shut off the flow by restricting it, and the discharge line should be equipped with a relief valve to discharge fluid back to the tank. A flow/no flow operation like pulling a trigger on a carpet cleaner should start and stop the pump, not open and close a valve.

In the end, it might be easier for him to make his pump a removable assembly that can come up the building with him! (Wouldn't it be logistically difficult to run that sort of length of hose up 18 floors anyway?)

 

[AESMC]

ChasBean1: Thanks for your response. Something I left out earlier is that he actually has a special rig which includes the pump and hoses for carpet cleaning, but I don't have the specs on it right now. The rig is specifically made for carpet cleaning. It is truck mounted and to large to carry. There is also a vacuum to pick up the water.

When I see him the next time, I will ask him for the specs on the pump he is using and I'll get back to you. We were curious about the number of stories that the pump would be effective. Something made me think that there was a limit on how high the water could be pumped regardless of the strength of the pump.

 

[TBP]

There's a limit on how high a pump can suck. Practically, it's about 20 feet. Discharge is limited by the drive horsepower, and what the pump casing and discharge piping can stand.

I agree with ChasBean1 about hauling hose up multiple floors. It'll take a LOT of power to get it up there, and even if you can do that, it'll have to be supported to physically take the weight of the hose itself, AND being filled with water. I think if your buddy seriously wants to get into doing anything more than 3 or 4 floors up, he'll need a rig that will fit into elevators.

 

[AESMC]

TBP: Thanks for your response. The guy was telling me something about the pump supplies additional pressure which makes the cleaning superior to the smaller machines normally rented at a retail location. It's a commercial machine. Apparently, it has more horsepower, but I understand your comment. More than four floors would be pretty high. Although, he made a comment to me about a job he considered on the seventh floor.