Gravity Fed Water Pressure

[kittysmitty]

I'm looking at using one of those portable camping  hot water shower unit at my off grid camp. The unit needs min. of 20lbs water pressure. At the moment all I have is a gravity fed water system. Can  I get 20lbs pressure, if my water tank is high enough? How high? I want to avoid using any type of pump. Thanks

[bj]

   IF memory serves, a little over .4 pounds per foot of elevation.  So, 40 to 50 feet high.

[madlabs]

Those camping showers need water pressure? The ones I have used didn't. Or at least I just opened the valve and drained it on my head. Worked for me!

Jonathan

[ghurd]

What kind is it?
Never heard of one that needed a minimum pressure.

Most of the cabin water systems I have used have the storage tank up maybe 12~16'.  Not fire hose pressure, but more than plenty for shower, toilet, kitchen faucet.
You can certainly tell the difference between 10' and 14'.  I'd say 10' up is marginaly functional at best, but it worked.
G-

[kittysmitty]

Here is the one I was looking at.

http://cgi.ebay.com/Eccotemp-L5-Portable-Tankless-intstant-Water-Heater-lp-/220790505963?_trksid=p5197.m7&_trkparms=algo%3DLVI%26itu%3DUCI%26otn%3D5%26po%3DLVI%26ps%3D63%26clkid%3D637676181187850787

I do have one of these that work very well.

http://cgi.ebay.com/Zodi-Outback-Hot-Shower-Water-Heater-w-Stove-FREE-SHIP-/230581961996?pt=LH_DefaultDomain_0&hash=item35afc1850c

I don't think I'll raise the storage tank 50 feet in the air.

Thanks for the replys

[Boss]

From the description:   The portable tankless unit is an ideal unit for portable uses. It uses a standard garden hose adapter and fits right to a standard BBQ grill style tank. Perfect for portable and cabin applications. It also works great with a water pump in the event that water pressure is not available.
From http://www.campingworld.com/category/pumps-tanks/137

SHURflo Whisper King Demand Fresh Water Pump
I don't know anything about that site it just came up when I googled "RV water pump"  I'm pretty sure that Shurflo has a built in switch so it comes on only when the water is used.

[zap]

That Zodi model is pretty slick.  I love the hand pump... that seems like a great idea for a small solar setup.
I have an old "water only" stainless steel fire extinguisher that I might have to mess around with.

[ghurd]

I still can not understand why 20 PSI is 'required'.
Only guess I have is so people don't return them for being too low flow?

Sounds like it will not overheat itself. (temp adjustable thermostat, and shower head has On/Off control)

Owners Manual says "Ideal operating use with water pressure between 20-80 PSI."  Less than ideal should still function?

Later it says (trouble shooting section) "Water is flowing, but there is no hot water coming out:  b- Ensure that you have adequate water pressure of at least 20PSI, sustained."
Possibly there is a safety switch?

They have an 800 number.  I'd call them and ask!
G-

[hydrosun]

I can only assume this is an on demand water heater that turns on when water is being used. A sensor internally switches from pilot light to full when the water pressure drop across the sensor shows that water is flowing. I have a small paloma instant water heater that needed at least 15 psi to work. And if the shower head was plugged the flow slowed and the pressure drop wasn't enough to turn on the higher flame. What was really annoying was when it was partially plugged and it would work when the pressure pump kicked on and then it would shut off the flame when the pressure dropped before the pump kicked back on. My wife was not amused when her shower went from hot to cold to hot again. We no longer use it, but rely on solar hot water and a wood stove water coil to make sure the water is consistently hot.
So you may get your unit to work on less pressure if your shower head has less restriction so the flow is faster. That will increase the pressure drop across the sensor. It will also decrease the temperature.
Chris