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Bassosa

Best practices for water pump purchase

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We're about to purchase two water pumps which will supply 8 hotel rooms each. The water pumps are underground and water needs to delivered to the ground floor, as well as second and third floor. 

 

What are things to look out for when buying?

 

So far, I've noticed that it needs to be "constant pressure" pump but what do I do to prevent sudden pressure changes in the system when say someone decided to have a shower? Is that what a pressure tank is for?

Also, is getting inverter technology recommended? As our pumps serve many outlets I expect much use, so I'm leaning towards getting the more expensive inverter pumps.

Does inverter also mean less "shock loading" on the system. It is my understanding that a normal water pump is either on or off, so more shockloading as the pump cycles on. Does an inverter alleviate this?

 

Thanks for your feedback.

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Buy Grundfos pumps, very well enginered and quality manufacture, a wide range of types and models, more expensive but well worth it.

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13 minutes ago, Bassosa said:

So far, I've noticed that it needs to be "constant pressure" pump but what do I do to prevent sudden pressure changes in the system when say someone decided to have a shower? Is that what a pressure tank is for?

A lot of them come with integrated pressure tanks. This tank will dampen the pressure increase when the pump turns on. A gradual pressure increase will occur until the water pressure builds up to your high pressure limit setting. You can optionally add a big pressure tank to the system to reduce pump on/off cycling frequency. A company like grundfos will listen to your requirements and recommend a suitable pump and accessories.

 

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3 hours ago, Bassosa said:

So far, I've noticed that it needs to be "constant pressure" pump but what do I do to prevent sudden pressure changes in the system when say someone decided to have a shower? Is that what a pressure tank is for?

Also, is getting inverter technology recommended? As our pumps serve many outlets I expect much use, so I'm leaning towards getting the more expensive inverter pumps.

Does inverter also mean less "shock loading" on the system. It is my understanding that a normal water pump is either on or off, so more shockloading as the pump cycles on. Does an inverter alleviate this?

Yes inverters will avoid shock loading. I suggest the same as I have as it is probably perfect for your case, you can also increase the pressure on the pump if you find it not enough or too much.

7FFBFC71-69CA-4AC0-9587-9BF1AD073F52.thumb.jpeg.daf5726ae64c910fbafc75bf643e5e87.jpeg

the guarantee is superb, one year from installing ours developed a problem and when bringing it in (because 50km from the dealer) it was instantly replaced with a new one.

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How many rooms on each floor? Ground floor Kitchen? Bar? 

 

Are all floors connected to the same pump or have separate piping? 

 

Hot or cold water.

 

Just for example. 

 

Buy local that way any repairs etc will be easier

 

Just thinking that most commercial premises have a water tank on the roof. 

 

 

water-pump-specs.jpg

 

 

Edited by VocalNeal
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Talk to a local pump supplier or plumber with commercial experience. Avoid odd job plumbers.

 

Most businesses including ours who depend on reliable water pumping use multi centrifugal pump systems with suitably sized pressure tank. Some systems will use multiple pumps as demand changes while others will operate pumps on a duty cycle leaving redundant backup.

 

These reliable easy to repair systems are available all around Thailand in various sizes and flavours. Smaller systems (<= 1hp) are often custom built on site. 

 

The aim is to provide fail backup to the whole service and build using components that are easily sourced.


Example pump  stations. Available .5hp - xxhp

 

pumpset.jpg.be5bb3f22b980692195b387120057f5b.jpg

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21 hours ago, Fruit Trader said:

Talk to a local pump supplier or plumber with commercial experience. Avoid odd job plumbers.

 

Most businesses including ours who depend on reliable water pumping use multi centrifugal pump systems with suitably sized pressure tank. Some systems will use multiple pumps as demand changes while others will operate pumps on a duty cycle leaving redundant backup.

 

These reliable easy to repair systems are available all around Thailand in various sizes and flavours. Smaller systems (<= 1hp) are often custom built on site. 

 

The aim is to provide fail backup to the whole service and build using components that are easily sourced.


Example pump  stations. Available .5hp - xxhp

 

pumpset.jpg.be5bb3f22b980692195b387120057f5b.jpg

In the meantime, we spoke to some technicians and are indeed considering a similar system as pictured by you. It seems to be the best way to achieve guaranteed water pressure wherever you are in the building, irrespective of load. 

 

They do tell us that the pump should be very close to the water tank. Is that true? In our case that is not that convenient.

We need something proper because our building is multi-story and the builder only installed 1" water pipes even though we made it clear from the beginning that we want decent water pressure throughout the building.

None of the technicians we spoke to so far, will tell us what water pressure we can achieve up high. They just commit to water pressure "at the pump". 4 bar with probably 3 bar up high is what they think.

We're talking to Grundfos but were also offered a Espa system. Apparently made in Spain? Does anyone have any experience with this brand?

Edited by Bassosa

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2 hours ago, Bassosa said:

They do tell us that the pump should be very close to the water tank. Is that true? In our case that is not that convenient.

Stock tanks are best located close to the pumps but its not essential. To determine feed line size, your technician should first survey to find stock tank distance and location above or below pump inlet ports.

 

1" water pipes can service many rooms on a single floor. Problems start when a 1" pipe is in series through several floors. 

Each floor should have its own line from ground or off a main riser.

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@VocalNeal said a rooftop tank with a pump by it is almost certainly going to give the best pressure. The hitachi pumps shown above usually give a maximum of about 2.8 bar and that is going to be plenty if pumped down from the roof. If you want higher then the Grundfos will go up to at least 4 bar over inlet pressure 

AA9182FD-A282-46E8-860D-C5197C4C7C97.jpeg.1069520fe3bf9fe02fd7bdccf925f425.jpeg

 

 

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Just now, sometimewoodworker said:

@VocalNeal said a rooftop tank with a pump by it is almost certainly going to give the best pressure. The hitachi pumps shown above usually give a maximum of about 2.8 bar and that is going to be plenty if pumped down from the roof. If you want higher then the Grundfos will go up to at least 4 bar over inlet pressure 

AA9182FD-A282-46E8-860D-C5197C4C7C97.jpeg.1069520fe3bf9fe02fd7bdccf925f425.jpeg

 

 

 We weren't able to have a rooftop tank unf.

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You might consider installing a regulator on the ground and first floor if you want decent flow on the second floor on the cheap.


Sent from my iPhone using Thaivisa Connect

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1 hour ago, RideJocky said:

You might consider installing a regulator on the ground and first floor if you want decent flow on the second floor on the cheap.


Sent from my iPhone using Thaivisa Connect

Flow regulators are available for fitting to each tap / shower outlet, this will assist in controlling outlets on the lower level. 

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11 minutes ago, Artisi said:

Flow regulators are available for fitting to each tap / shower outlet, this will assist in controlling outlets on the lower level. 

Do you mean to control (potentially) excessively high water pressure on the lower levels?

Edited by Bassosa

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45 minutes ago, Bassosa said:

Do you mean to control (potentially) excessively high water pressure on the lower levels?

Mainly control flow which is your main concern so as to ensure there is sufficient flow at the second level and furthest point from the pump at the pressure you elect. 

 

Actually your "problem" is not a problem to someone who has the necessary detail on hand and knows how to use it. 

There is detail available to establish the necessary flowrate for your project based on the number of rooms, and the number of occupants. You know the height from the source to the highest point, you know the maximum pipe run, you know the pipe diameter and with flow restricters you can calculate the maximum flow demand at the pressure you want at the outlets. 

After sorting out the flow rate and head (pressure) required at the pump discharge you can then look at selecting the necessary pump/s.

With all the detail to hand, probably a 10 minute exercise. 

It's 20 years since undertaking a calculation like this which I would be happy to help with, but unfortunately I no longer have the detail available to do it. 

Edited by Artisi

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1 minute ago, Artisi said:

Mainly control flow which is your main concern so as to ensure there is sufficient flow at the second level and furthest point from the pump. 

 

Actually your "problem" is not a problem to someone who has the necessary detail on hand and knows how to use it. 

There is detail available to establish the necessary flowrate for your project based on the number of rooms, and the number of occupants. You know the height from the source to the highest point, you know the maximum pipe run, you know the pipe diameter and with flow restricters you can calculate the maximum flow demand at the pressure you want at the outlets. 

After sorting out the flow rate and head (pressure) required at the pump discharge you can then look at selecting the necessary pump/s.

With all the detail to hand, probably a 10 minute exercise. 

It's 20 years since undertaking a calculation like this which I would be happy to help with, but unfortunately I no longer have the detail available to do it. 

Thanks for your comment.

I will ask the people bidding for the gig to provide the calculation once we proceed a little further into the project and they have more insight into the situation. Seems like a good exercise to cut the wheat from the chaff.

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