View Full Version : Indian guy needs some advice
10-20-2010, 03:18 AM
We are on the metrics system so I'll do my best to convert everything to SI system. I have zero plumbing knowledge so guys please go a bit easy :)
I'm trying to upgrade two bathrooms in our house to high pressure showers and health faucets and would like to know what specs pump I would require.
The idea is to have about 70 psi pressure which I assume is good enough(read on the web) for optimal usage of shower, health faucet and wash basin. I do not know what the current pressure is but it takes about a painstaking 120 secs to fill a 5 gallon bucket of water.
What pump will I need? Plus what pipe sizes would I need? The bathrooms are in the top floor of the house and we have a overhead tank which is about 1000 gallons in size. The piping distance from the tank to the bathoom is around 50-75 ft.
Also what are some good shower head brands in the US? Will I be able to use them in India? Can anyone provide an online webstore link of a reputed company?
10-20-2010, 06:24 AM
We can estimate your current pressure if you know the vertical distance from your bathroom to the bottom of the water tank (you can use meters). Since the bathroom is on the top floor, the pressure is lower than if the bathroom was on the bottom floor.
For instance, say it is 2m from the bathroom sink to the roof and then say the tank bottom is 3m above the roof. When the tank is close to empty, the pressure is 5m of head (about 16ft). You get ~0.5psi per ft of head (little bit less, actually), so your current pressure would be ~16ft*0.5 = 8psi (quite low)
You can use actual distances to see what you get, but you probably won't be more than 8-10psi unless the tank is on a very tall tower.
Let's assume that 8psi is correct and let's say the new pressure is 70psi.
(70/8) = 8.75
sqrt(8.75) = 2.96
This means that the water will now flow about 3x faster, so you'll fill that bucket in 40 secs. This works out to 7.5 GPM.
Does this tank only feed these bathrooms or are there other houses/apartments that it connects to?
Typical plumbing size in the US is 3/4" (~1.9cm) as the main feed line. Then you might run 1/2" (~1.27cm) to each bathroom (1/2" hot line, 1/2" cold line).
For the pump, there are probably several options, but you would be best getting a pump in India or Europe. India and Europe use 240v, 50Hz electricity. USA is all 60Hz with most house voltages at 110v and some larger items (water heater, stove, etc.) use 220v. The US pumps often come in both 110v and 220v, but they are designed for 60Hz power and not 50Hz.
For the shower head, you'll also want to go with something from India or Europe as the US head might not fit the threads on your plumbing. The shower head design won't matter that much once you get the pressure up.
The only issue that I see is how the tank is filled. Is it rain water collection or is it pumped from someplace? Since you'll have better flow with the new system, you will go through the water a little bit faster unless you take shorter showers.
10-20-2010, 10:48 AM
You need to know the pipe size. Pressure will help, but if the pipe size is too small, the velocity of the water through the pipes can actually damage them when asked to provide a big flow. Here, anything over 40psi is generally okay. 50-60 is okay. Over 80psi is too much, and should be regulated down. Most fixtures are rated at a minimum of around 40psi.
10-21-2010, 07:13 AM
The vertical distance must be around 2 meters at the most. But heres the deal. We can't use the inwall piping because the pipes are 25 years old and then everyone around have been saying for years that the pipes will burst because of the pressure.The tank is above the bathroom roof (not directly above but a adjacently above) and it linked to the structure. We have a ventilator which is quite big and plan to lay a connection from there. It will be external piping and will look ugly but right now function wins over aesthetics. Although we will have only shower heads we would like the pressure to be good enough if we choose to install shower panels. Been reading all over the web and 60-70 psi seems to be a safe range for future proofing it. Do you guys agree? My questions are :
1. What size pump would I need?
2. What size pipe would I need for the feed line?
3. Planning to get a 50 gallon horizontal heater as well. What size piping would I need for the hot water line and cold water line?
4. Do heaters get damaged if you leave them to atmospheric conditions and weather? I doubt we will have space in the bathroom to install one so was wondering if I could put it on the top. Weather averages between 90 and 110f. We have a two months rain season as well.
5. If 60psi is what one should shoot for does will it be a problem for the health faucet(the anal cleansing one)? Will it be too much for the faucet to handle? Right now the pressure is so low that water trickles from the faucet.
10-21-2010, 08:17 AM
I agree that 60-70 psi (~4.5 bar) would be good. Do you know what material your pipes are made out of? In the US, the popular ones are copper, PEX (plastic tubing), CPVC, and galvanized (older houses). Running pipes on the outside of the building is not an issue unless you are in an area where it can freeze in the winter. For the water heater, most would not last long exposed to the weather (rust). If you have to keep it outside, build a small building for it with a roof that will keep the water off of it.
1. For pump, there are probably a few options. I would probably make a setup like you would for a well (pump, pressure tank, pressure switch). This way, the pump will only run when needed. If you run the pump with no flow, it can damage the pump. You could maybe put a submersible style pump in the tank and pump it out that way or maybe a jet pump with the pump inlet connected to the outlet of the tank. Might also be a good idea to add a level switch in the tank so that the pump will not run if the tank is empty. Since the water is coming from above, the pump won't need to be very large. See, flow drops when having to pump up, so you need a larger pump in a deeper well. Since water is coming from above, it is easier for the pump and it will flow better. I haven't checked any pumps for you, but something that could do 12-15 GPM would be plenty for your two bathrooms. Probably a 1/2 or 3/4 HP pump.
2. The outlet of the pump would use 3/4" or 1" pipe/tubing. Either of those should be plenty for your situation.
3. Same as above. U.S. water heaters use a 3/4" line for the in/out on the water heater. For the cold, you might run 3/4" from the roof and then maybe 1/2" into each bath (you could run everything in 3/4" if you wanted to).
4. See the start of my message. Without freezing weather, you just need something to keep it out of the rain. It would still be better inside, though. Water and high humidity will cause it to rust.
5. 60-70 psi should be fine. Everything in the US is typically designed for 80 psi or more. We call what you are talking about a 'bidet'.
Since you are saying only 2m from the bathroom to the bottom of the tank (I guess the tank is not elevated above the roof), your current pressure is about 3 psi or so when the tank becomes close to empty. With pressure that low, you would love any improvement.