Any experience of gravity fed water systems?
Any experience of gravity fed water systems?
Similar to my previous topic in this forum. I am having a new house built and should like to avoid using an electric pump (I had no water yesterday for an hour because one of the electrcal phases had gone). The estate I am on has a water tower the platform of which is about 13 meteres above my single storey house. So what I am thinking is install my houses own tank on a smaller tower say about 1-2 meter above the house level let it fill by pressure as from the main tower and provide water to the house by gravity. Anybody any idea if 1-2 meter is right. Any knowledge of t6he pluses and minuses of this approach would be appreciated.
-
HansMartin
- Professional
- Posts: 270
- Joined: Tue Dec 27, 2005 7:50 am
- Location: Back Home in CA
Being metrically challenged, I'll respond in English (American and Yemenese) units.
13 metres is 36.62 feet which is equivalent to 17.15 pounds per square inch of pressure (1 psi = 2.37 feet of water). The minimum design pressure for most public water systems in the US is 20 psi; and a prefered minimum is 40 psi.
So 2 meters only gives you 5.6 psi. Not nearly adequate. You would need a booster pump in that case.
13 metres is 36.62 feet which is equivalent to 17.15 pounds per square inch of pressure (1 psi = 2.37 feet of water). The minimum design pressure for most public water systems in the US is 20 psi; and a prefered minimum is 40 psi.
So 2 meters only gives you 5.6 psi. Not nearly adequate. You would need a booster pump in that case.
In practical terms you need the tank to be above the level of the shower head - preferably about a metre above that - so what it really means is a storage tank in the roof space or at about that level. From what I have seen of newly built Thai houses, the roof structure and ceiling joists will not take the weight of a tank, so it would need to be located outside. If you have an area of flat roof in cast concrete (as many of the houses have for situating air-con units) then that may be structurally OK. Don't forget - water is very heavy and to make it worthwhile you are going to need a tank of around 1000 litre capacity.
-
Guess
- Deceased
- Posts: 3470
- Joined: Fri Jul 22, 2005 3:01 pm
- Location: BangSaphan. Laurasia. Sub thumb
In answer to original post. Yes I do.
But Hans has explained the details and technical requirements a lot better than I could.
The tank that you proposed is wholly inadequate.
The three main things that you need to know first are:
How far is the last output from the tank going to be.
How much pressure do you need.
What is the highest output you require. (E.g a roof garden stand pipe or something like that.)
A 1000 Litre (1 Tonne) tanks is the absolutle minimum. Smaller are available nut not adequate for a modern house.
In my place which is not modern I had to build a reeinforced concrete roof on top of the second floor bathroom. The outlet of the 1.6 tonne tank is 1 metre above ground level. but is never really been put to the test for any period of time because my Thai builders assumed that I was a jibbering idiot and ho know idea what I was ralking about and did it in there own way. Tha F*** up cost me 20,000 baht about one year later.
As has been mentioned water is heavy so any platform needs to hold the mass of the water, the mass of the tank and the mass of the troop of builders that will leap about on it when you encounter the slightest problem.
There is another solution if saving money is not the primary concern. That is to have two parallel outlets from the tank. The first one to feed the house's critical outlets in the house like the main bathroom and the kitchen which shoud be both on the ground floor by gravity. The second to supply everthying else and would be constant pressure pump driven. This BTW is theory only. I am sure HansMartin can correct me if I am wrong about this.
Another peice of advice is firstly make a plan then run it by someone here who knows about this technology, A good guy to talk to is Peter Wilson you hangs out in Top Mark's Hotel Bar.
I would be interested to know how you get on.
But Hans has explained the details and technical requirements a lot better than I could.
The tank that you proposed is wholly inadequate.
The three main things that you need to know first are:
How far is the last output from the tank going to be.
How much pressure do you need.
What is the highest output you require. (E.g a roof garden stand pipe or something like that.)
A 1000 Litre (1 Tonne) tanks is the absolutle minimum. Smaller are available nut not adequate for a modern house.
In my place which is not modern I had to build a reeinforced concrete roof on top of the second floor bathroom. The outlet of the 1.6 tonne tank is 1 metre above ground level. but is never really been put to the test for any period of time because my Thai builders assumed that I was a jibbering idiot and ho know idea what I was ralking about and did it in there own way. Tha F*** up cost me 20,000 baht about one year later.
As has been mentioned water is heavy so any platform needs to hold the mass of the water, the mass of the tank and the mass of the troop of builders that will leap about on it when you encounter the slightest problem.
There is another solution if saving money is not the primary concern. That is to have two parallel outlets from the tank. The first one to feed the house's critical outlets in the house like the main bathroom and the kitchen which shoud be both on the ground floor by gravity. The second to supply everthying else and would be constant pressure pump driven. This BTW is theory only. I am sure HansMartin can correct me if I am wrong about this.
Another peice of advice is firstly make a plan then run it by someone here who knows about this technology, A good guy to talk to is Peter Wilson you hangs out in Top Mark's Hotel Bar.
I would be interested to know how you get on.
[color=blue][size=134]Care in the community success story.[/size][/color]
I understood that the 1000 litre tank was a requirement in the Hua Hin municipality for new dwellings but to put it into perspective, new homes in the UK have traditionally had either a 227 litre cold water storage cistern (for indirect systems) or 114 litre cold water feed cistern (for direct systems only serving the hot water cylinder from the feed tank), usually in the loft space, which feeds the property by gravity. Good mains pressure would be required for the direct system but the indirect system can be used where mains pressure is not so good and the 227 litre tank is considered to provide a large reserve of water. Of course, here in Britain we only bath once a week on a Sunday evening!Guess wrote:A 1000 Litre (1 Tonne) tanks is the absolutle minimum. Smaller are available nut not adequate for a modern house.
-
HansMartin
- Professional
- Posts: 270
- Joined: Tue Dec 27, 2005 7:50 am
- Location: Back Home in CA
1000 litres is 262 gallons, and a typical person in the US uses about 70 gallons/person/day. So this is baiscially 1 days supply -- not very much if you are concerned about reliability. This also weighs about 2200 pounds, so I am not sure that I would want this in my loft space.
What I have typical seen in BKK (especially in the suburbs) is an at-grade metal storage tank with a booster pump and a pressure tank with pressure switches to operate the pump. This is the way I would go if I were concerned about pressure and volume. I would also include by-pass piping to run off the municiapl sytem when adequate, and keep this system for backup.
It shouldn't be all that expensive, but it needs to be factored in when building or purchasing a house.
It sounds like the HH municipal water system has some reliability isssues !!!
What I have typical seen in BKK (especially in the suburbs) is an at-grade metal storage tank with a booster pump and a pressure tank with pressure switches to operate the pump. This is the way I would go if I were concerned about pressure and volume. I would also include by-pass piping to run off the municiapl sytem when adequate, and keep this system for backup.
It shouldn't be all that expensive, but it needs to be factored in when building or purchasing a house.
It sounds like the HH municipal water system has some reliability isssues !!!
Interesting thread here. Maybe someone can fill me in on water tower systems.
I will be building on an estate with a water tower and have no previous experience of this.
Does it mean my house water will be gravity fed?
Are there any problems people have encountered with systems such as this? Supply, pressure etc?
Thanks to anyone who can share their experience(s).
I will be building on an estate with a water tower and have no previous experience of this.
Does it mean my house water will be gravity fed?
Are there any problems people have encountered with systems such as this? Supply, pressure etc?
Thanks to anyone who can share their experience(s).
I wish I had one. I am frequently out of water and it sucks (I've been out of water all day today). Sometimes when we do have water the pressure is so low it won't kick on the pressure switch governing the water heater.
The Thais at the hardware store talked me out of the pump and I put a big plastic trash can in bathroom instead.
This problem is only going to get worse. This area is so dry cactus is growing all over the place. Demand has surely outstripped supply. I heard the water table has salt water encroachment due to overpumping.
Another they could do is fix all the leaks in the klongs (canals) they are losing alot of water they release.
The Thais at the hardware store talked me out of the pump and I put a big plastic trash can in bathroom instead.
This problem is only going to get worse. This area is so dry cactus is growing all over the place. Demand has surely outstripped supply. I heard the water table has salt water encroachment due to overpumping.
Another they could do is fix all the leaks in the klongs (canals) they are losing alot of water they release.
If the job is big call the Pig