Jump to content

Nominations for Tractor of the Month
Garden Tractors and Parts on eBay



Photo
- - - - -

My Quest For Off The Gridness


  • Please log in to reply
32 replies to this topic

#1 BairleaFarm OFFLINE  

BairleaFarm

    Member

  • Senior Member
  • -GTt Supporter-
  • Member No: 8328
  • 1,201 Thanks
  • 1,725 posts

Posted November 18, 2013 - 10:18 AM

There is an equation I'm sure but I've got no clue how to figure it out. If I had a 300 gallon water tank and 3/4" piping coming into my house how far in the air would the tank have to be too maintain 50psi of water pressure in the house?
  • hamman and oldedeeres have said thanks

#2 cityboy2977 OFFLINE  

cityboy2977

    ordinary average guy

  • Senior Member
  • Member No: 6650
  • 117 Thanks
  • 179 posts
  • Location: Mancelona, Michigan

Posted November 18, 2013 - 11:11 AM

i have no clue. but i have given this a lil bit of thought for my own garden irrigation.

 

would it be better to start with say 2" pipe and step it down to get a better pressure  ? not sure how long of a run or how high it would have to go.

 

i was thinkin of a shallow well pump & bladder tank hooked up to solar. stepped down from 1 1/4" to pump and 1/2" from tank.

i already own a pump(Flotec) that can be switched for 115 or 220v, so easily ran off solar.

 

im just throwin ideas out there. im sure someone more educated in this field will chime in.


  • hamman and oldedeeres have said thanks

#3 JDBrian OFFLINE  

JDBrian

    Super Moderator

  • Super Moderator
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 2507
  • 9,574 Thanks
  • 14,136 posts
  • Location: Hubley, Nova Scotia - Canada

Posted November 18, 2013 - 11:13 AM

Looks like 115.5ft The formula is 2.31 x head(feet) = pressure. If you are using a fluid other than water you need to correct for Gpecific Gravity. That 115.5 ft is just to get the 50psi. You'd need more to compensate for pressure prop in the pipe. That depends on the diameter, length of pipe and flow .

 


  • hamman, HDWildBill and oldedeeres have said thanks

#4 Texas Deere and Horse OFFLINE  

Texas Deere and Horse

    RED Wild Hogs, Horses & Deeres

  • Staff Admin
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 1435
  • 14,464 Thanks
  • 15,392 posts
  • Location: East of San Antonio Texas

Posted November 18, 2013 - 11:22 AM

Here's a place I found that has several formulas for figuring things. I can't find one that will determine Pressure, but it does tell you volume and flow.

 

http://www.calctool....azen-williams_g


  • hamman and oldedeeres have said thanks

#5 BairleaFarm OFFLINE  

BairleaFarm

    Member

  • Senior Member
  • -GTt Supporter-
  • Member No: 8328
  • 1,201 Thanks
  • 1,725 posts

Posted November 18, 2013 - 11:24 AM

I've got a well pump but I was tossing ideas to not use any power. 115' is higher than I would have ever imagined
  • hamman and oldedeeres have said thanks

#6 TAHOE OFFLINE  

TAHOE
  • Senior Member
  • -GTt Supporter-
  • Contributor
  • Member No: 24522
  • 6,504 Thanks
  • 4,955 posts
  • Location: "Hamiltucky" Ohio

Posted November 18, 2013 - 12:26 PM

Wow, that is a pretty high stand you're gonna have to make :bigrofl:

 

not sure how much pressure they put out, but I know camper pumps are 12v. If you can find one that puts out enough pressure, would be easily to run off a 12V batttery. They also have a pressure shutoff so could be an on demand type thing when you open valve. Probably some decent pressure 12V pumps out there.  

 

I have a shallow well I would like to hook up to a solared powered pump, it's only 22-23' deep I think. It had an old hand pump on there, may just try to get another one and go from there.

I got a 300 gal plastic tote, thinking about rigging it up to catch rain water from gutter to water the animals.


Edited by TAHOE, November 18, 2013 - 12:28 PM.

  • oldedeeres said thank you

#7 Team_Green OFFLINE  

Team_Green
  • Senior Member
  • Member No: 10410
  • 2,211 Thanks
  • 2,305 posts
  • Location: East of Edmonton...

Posted November 18, 2013 - 04:29 PM

aim for 30 psi (unless you really need 50 for something).. We went down to 30 a year ago and kept the shower time the same. It helped us cut back on water usage big time. Wife wasn't happy at first but she got used to it.. 


  • Alc and oldedeeres have said thanks

#8 New.Canadian.DB.Owner OFFLINE  

New.Canadian.DB.Owner
  • Senior Member
  • Contributor
  • Member No: 10178
  • 2,224 Thanks
  • 1,451 posts
  • Location: Trenton, Ontario, Canada

Posted November 18, 2013 - 04:48 PM

Looks like 115.5ft The formula is 2.31 x head(feet) = pressure. ...

I'm no math expert, and it is a while since I've been in school, but 2.31 x 115.5 feet = 266 psi.

 

I'm thinking more like 21 feet. (2.31 * 21 = ~48 psi)


  • oldedeeres said thank you

#9 JDBrian OFFLINE  

JDBrian

    Super Moderator

  • Super Moderator
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 2507
  • 9,574 Thanks
  • 14,136 posts
  • Location: Hubley, Nova Scotia - Canada

Posted November 18, 2013 - 05:04 PM

I'm no math expert, and it is a while since I've been in school, but 2.31 x 115.5 feet = 266 psi.

 

I'm thinking more like 21 feet. (2.31 * 21 = ~48 psi)

No, I got it backwards. The answer is correct but the pressure and head are reversed in the formula. should be 2.31X pressure (PSI)=head ( feet)

 It would be nice if 21ft would generate 50psi but when you think about it that's a lot of pressure to be supplied by the weight of the water alone. 

Heres a link to some more equations. With water the Specific Gravity (S) is taken as 1 so it simplifies the calculation. 

http://www.engineeri...sure-d_663.html


  • Texas Deere and Horse, HDWildBill and oldedeeres have said thanks

#10 JDBrian OFFLINE  

JDBrian

    Super Moderator

  • Super Moderator
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 2507
  • 9,574 Thanks
  • 14,136 posts
  • Location: Hubley, Nova Scotia - Canada

Posted November 18, 2013 - 05:08 PM

There is a man who lives near here who recently built a big house off the grid. He uses a DC water pump so I know they are available. The DC pumps are more efficient than a conventional 240v pump so you use as little energy as possible for pumping water. 


  • Texas Deere and Horse, HDWildBill and oldedeeres have said thanks

#11 toomanytoys84 ONLINE  

toomanytoys84

    Aaron

  • Senior Member
  • Member No: 45129
  • 8,243 Thanks
  • 5,082 posts
  • Location: Ohio

Posted November 18, 2013 - 05:52 PM

Start bigger and step down. We gravity fall water into the coal mine 8" line down to 4" And it makes crazy pressure.
  • oldedeeres said thank you

#12 David Brown OFFLINE  

David Brown

    I said I work on them. I never said I fix them!

  • Senior Member
  • Contributor
  • Member No: 8570
  • 4,219 Thanks
  • 2,316 posts

Posted November 18, 2013 - 05:59 PM

Not sure but I think we might be missing a variable here.  What about the amount of water on hand?  A full tank will produce more pressure than one that is only half full.  Another thing is, how do you plan to fill the tank?


  • oldedeeres said thank you

#13 HowardsMF155 ONLINE  

HowardsMF155

    Tractorholic

  • Senior Member
  • Member No: 4243
  • 2,699 Thanks
  • 2,916 posts
  • Location: Central NC

Posted November 18, 2013 - 06:12 PM

I lived for years with a 1000 or so gallon tank supplied by a pump.  The bottom of the tank was perhaps 10 feet high.  The hill it was on added from 10 to 20 feet more.  The supply was 3/4 pipe over perhaps 300 feet of distance.  Water was slow to start running, but once it got going there was a good flow.  No aerators, no shower, no sprinkler operation.  

 

In the US, depending on where you are, domestic water pressure is usually regulated to 50 psi or less.  That is, if supply water pressure exceeds 50 psi a pressure regulator is installed as part of the house plumbing.  Best off the grid solution I can think of is to combine a windmill with a water pump pushing water into the tank.  


  • boyscout862 and oldedeeres have said thanks

#14 LilysDad OFFLINE  

LilysDad

    Cat Lover

  • Senior Member
  • -GTt Supporter-
  • Contributor
  • Member No: 10443
  • 9,687 Thanks
  • 7,693 posts
  • Location: N. Illinois, DeKalb County

Posted November 18, 2013 - 08:25 PM

A lot of the farmsteads around here once had a raised water tank that was supplied from a well pump. It seems like they were usually around 15 - 20 feet tall.


Edited by LilysDad, November 18, 2013 - 08:26 PM.

  • oldedeeres said thank you

#15 Copperhead300 OFFLINE  

Copperhead300
  • Member
  • Member No: 49297
  • 5 Thanks
  • 9 posts
  • Location: Asheville, NC

Posted November 18, 2013 - 08:42 PM

To obtain 50 psi of water pressure, the bottom of the tank should be 78 feet above the faucet.  Fifty psi is asking for trouble on faucets, toilets and washing machine valve's and seals.

Thirty feet of head (the distance between the bottom of the tank and faucet) will produce 28 psi, but if you absolutely need higher pressure then 50 feet of head will produce 37 psi.


  • oldedeeres said thank you




Top