This post is not specifically about the Airstream itself but rather the system I use for getting water while off the grid. This is probably the thing I get asked about most often so I will detail my setup below.
To get a fully functioning, safe, off grid water supply to fulfill the needs of 2 people living in a tiny home or trailer will cost at least 3 thousand dollars. Depending on the size you want, it can be significantly more than that too, for example a house will need a much larger system than the Airstream does.
Here are the supplies I used:
- A 250 gallon fresh water cistern (approx $500.00. Note: after using this size for a season, I would recommend larger. Additional units can be added on later too)
- ABS pipe and glue, teflon tape, various fixtures, angles, etc… (this can vary depending on how your setup goes. (Budget a couple hundred for this, small parts can add up)
- Pex pipe (cheap, you wont need much)
- Particle water filters (I used 20 micron, 10 micron, 5 micron and 1 micron) ($200.00-$300.00)
- A jet pump with reserve tank ($500.00)
- Foot valve ($20.00)
- Some type of purification system, ie. UV, reverse osmosis, etc…($800.00)
- Eves trough and ABS/PVC pipe and angles to connect to cistern ($100.00)
Below is an image of the cistern with the rain water input coming out the top. This cistern is 250 gallons, however I am thinking of adding an additional 500 gallon next year. 250 gallons will do 2 people approximately one week worth of dishes, showers, etc. If you plan on doing laundry or if you have a flush toilet as opposed to composting, it will take significantly more water. Fortunately, the system is easy to expand on and you can add additional storage at any time.
I have heard people advise that potable water storage should not be placed directly on concrete as there could be issues with some components of the concrete seeping into the water supply somehow, I’m not sure if there is any truth to this, however I placed mine on some pallets just to be safe.
The second photo shows the foot valve, this is submerged and the pump draws water from here.
In the third photo you can see all three connections: 1. The rainwater tube coming in. 2. The foot valve line out to the pump. 3. An overflow outlet just in case it rains too much before the water is used.
Below are a few photos of the pump and the 6 gallon reserve tank. This pump provides excellent water pressure, just like you would find in a regular home. From the pump, there is pex line leading to the first of several filters. I placed the 20 micron and 10 micron filters in where the pump is and used my remaining filters and the water purification unit directly installed onboard the Airstream so that they will always be in use regardless of the water supply. Any clear hoses that must be used should be kept out of direct sunlight to discourage bacteria growth.
These pumps often require installing your own electrical cord. It can be done with little electrical experience. Here is the wiring job that I did, its basically just a matter of matching up the coloured wires.
Below is one of the most important components to this entire system – the UV filter. Without this your water will be useable but should not be consumed. This is a 12V Sterilight UV water filtration system so even in the worst case scenarios, if I cannot run my inverter or there is no shore power, I will still be able to get fresh water since its a 12V system. Fairly easy to maintain – the lamp should be replaced annually and the filters changed regularly too. Its a decent sized unit so fitting it in the space allotted by a tiny home or trailer can be a challenge, especially considering you need about twice that room in clearance for doing lamp replacements. We had to angle it under the kitchen counter and will need to remove a shelf to do the replacement.
Lastly, here are some photos of the eaves trough which leads to the cistern. Right now I have a 15ft section but that will be doubled next spring. We placed a mesh screen over the hole to prevent larger debris from getting into the cistern and clogging up the pump. Then we had to fit a few adapters to get it hooked into the hose that connects to the cistern. Ideally, we should have used a solid material like ABS/PVC and the diameter should be twice what it is, however due to a few issues we needed something flexible and thin so this is a reasonable solution.