How to Make a Gravity Fed Shower

How to Make a Gravity Fed Shower

Bathing from a bucket of showering with a manually pressurized can is not fun. Nothing beats the joy of standing under a showerhead and letting the water drip over you, washing away all the dirt and tiredness.

If you don’t have a municipal water supply, you have to invest some money and effort into creating pressurized running water to enjoy a shower.

There are many ways to do this from running on-demand taps to using a gravity fed water supply. Today, we are going to look at the gravity fed shower because its installation is always flexible enough and can fit into even the most budget-constricted homeowners or if you don’t have enough backup power to pump all that shower water on demand.

How Does a Gravity Fed Shower Work?

gravity fed shower

Gravity fed water systems use a simple potential energy principle. Anything on earth will fall towards the center of the earth. The higher up it is the more it falls.

Water stored at an elevation higher than the consumption point (faucets and showerheads) will fall (flow) hence giving you running water without an active pump.

The weight of the water column above your access point forces the liquid to keep flowing.

Actually, each foot of elevation you get above your shower or access point gives you around 0.433 PSI of water pressure.

To get the amount of elevation you need for your desired pressure:

  • Get the vertical distance/elevation between the bottom of the water tank and your water outlet
  • Multiply the reading by 0.1. This will give you the pressure in Bar
  • A 10 meter elevation gives (10 x 0.1 = 1) 1 Bar. You can find more detailed hydrostatic pressure calculations here
  • 1 Bar of pressure is equal to 14.5 psi

The EPA WaterSense directives test showers for flow rate compliance starting from 20 psi to 80 psi. Since pressure directly affects how much water flows through your showerhead, we will assume the 20 psi mark since it is enough to operate most running showers and will be kinder on your water reserves.

While 20 psi might be their standard, low pressure water showers will work just fine even with pressures as low as 5 psi. The water might not have the massaging impact of a higher pressure showerhead but is sufficient for cleaning up.

Creating a Gravity Fed Shower is as easy as Elevating Your Water Source

All you have to do to get running water through your shower is elevate the water source so that it is slightly above the showerhead.

This is why something as simple as a tank in the attic or a water stand slightly taller than your house will do the trick.

We are going to look at some tricks to help you achieve this with the minimum effort possible.

Locate Your Storage Tank Uphill

Locating your water tank up the hill will automatically set water source above your consumption point. People on areas with a significant gradient change could easily get flowing water from on-ground or underground storage without building a water tower.

The money you save by foregoing constructing an elaborate tower can compensate for the plumbing you need to get the water to and from the tank.

If the vertical/gradient change between the tanks and your faucets is not steep enough, you can get away with a shorter and cheaper water tower to boost the water pressure.

Build a Water Stand (Water Tower)

People living on small lots of land or leveled ground have no option but to build a water tower. It doesn’t have to be that high. Anything higher than your taps will give you water flow. It’s up to you to decide how much pressure you need.

Water towers can be built using:

  • Timber
  • Metal framework
  • Concrete

Do some math to ensure that the structure you set up is strong enough to support the weight of a full tank.

If you are planning on investing in a well, getting a pump system with a pressure tank is a cost and space-efficient alternative to a gravity-fed system especially if your land doesn’t offer the gradient you need naturally.

Placing a Small Tank on the Roof

The simplest approach to many tiny homes or RV dwellers is placing a small tank of water on the roof of their house or RV and filling it up by hand.

That small elevation is enough to give you a nice gravity fed shower. Just ensure that you don’t go for a very big tank. RVs and houses are rarely designed to take a lot of weight on the roof. Chances are you will have to refill your water reservoir once or twice a day unless you are very frugal with your running water.

How to Get Water to Your Tank

Once you have the reservoir for the hydrostatic pressure generation, you have to figure out how you’ll work against gravity to get the water up there in the first place.

Installing a Pump (Fast, Efficient, Costly)

Pumps are the easiest way to push your water up to the elevated reservoir. The power you choose depends on how much water you need, the elevation difference, and the power at your disposal.

If you are getting your water from a well or a borehole, you will need an elaborate pumping system that can lift the water from down below before pushing it up to the tank.

People getting their water from rainwater tanks, dams or rivers might need normal pumps that are not specialized to lift water so high.

Electric pumps are the most efficient. If you are running on solar, you will be better off going for DC solar water pumps or a specialized AC water pumping system to get the best off your off-grid electric system. You also have to be frugal since your pump will be limited by how much power you generate.

Alternatives to the electric pump are:

  • A gasoline powered pump
  • A Ram Pump if you have a slow flowing water source
  • Manual pumps

Carrying the Water There in Jugs (Cheap, Slow, Tiring)

If you don’t have the funds for a water pump or it isn’t practical for your setting, you could opt for carrying the water up there manually.

Fill a couple of jugs with water and carry it to your tank, empty it and return for more. You could make the process easier by using a vehicle to ferry the water there.

If you get your water from a bowser, have it deliver the water straight to your elevated tanks to avoid the extra hassle.

Heating the Gravity Fed Water

Normally, any form of water heater added to the system will have minimum water pressure and flow rate (Gallons Per Minute) to operate efficiently. If you choose compact tankless systems, look for something that accepts under 0.5 GPM and less than 30 PSI. The lower, the better.

Tanked systems might be more forgiving since heating the water makes it expand and boosts the pressure within the tank. You can get some good water pressure from a tanked system even with a meager input pressure.

Some off grid dwellings like pushing things further and using a solar water heater to warm up their water. Most of these systems come with preinstalled pumps hence water flow shouldn’t be a problem.

Check this too: What Size Generator Do I Need for My RV?

If you have a small tank on your roof that you fill up for each shower, you can always use your stove or fire to heat up some water, dilute it to an ideal showering temperature and lug it to your rooftop shower tank.

Bottom Line

Creating a reliable running shower is one of the biggest milestones when going off grid. We might take it for granted when the grid takes care of pressurizing out water but you wouldn’t know how good a shower feels when you miss it for long.

Remember to settle for a robust system that is good enough for you, your family, guests  and most importantly your lifestyle.