Water system for truck

[Carl2500]

I'm working on a water system for my truck. It'll be driving through Canada and Alaska.

I'd like to have a setup similar to RV's, with a fresh, grey, and black water tank. I'd like to carry 15 gallons of fresh water. What size grey and black water tanks would be about right?

Also if possible, I'd like to be able to pump water from a lake or river while camping, maybe into a separate holding tank, before it's filtered into the fresh water tank. That way I don't have to carry as much, and would always have good water around.

Another option I was thinking, would be to just pump in the water to the grey water tank, and use a filter between that and the fresh water tank.

Though I haven't heard of people filtering the grey water tank back into the fresh water tank, so I'm not sure if it'd be recommended.


For filters, I was thinking of making my own, using a .25 micron and .10 micron filter, with a few plastic pipe fittings. I've read that should take care of just about everything, and shouldn't cost too much.

As far as other accessories, I was looking at a small tankless water heater. Again I may be able to make this myself. It's basically just an electric element placed in water. If not they're only about a 120 bucks anyway.

It'll have a faucet on the sink, and water running to the back, where I can wrap a vinyle curtain around and take a shower if need be. It'll also have a hose on the outside of the truck.

I'll need a system to monitor the level of each tank. Maybe something as simple as a single LED when it's full.

And finally I'll need a strong enough water pump, to push the water to everywhere it needs to go. I'm up for any suggestions on how much PSI, and which brands are good.

So that's my thoughts on a water system for my truck. I welcome any questions or feedback, as it'll help me with my project

 

[RobinP]

Carl, sounds like you've got a big project!

Here are my first thoughts on this:

1) Treatment is expensive, in one form or another, and therefore should be done only on the water that needs it. The most expensive part of treatment is the power req'd. Whether you have a full blown de-sal system on a sail boat, or whether you are pushing water through a simple filter, it takes effort. If it's a pump, it's pressure and electricity. If you're pumping a small hiking filter, eat your wheaties. The point here is, treat the water on the discharge end of your fresh water tank, not everything you put into it.

2) Don't mix waste water with fresh water. The type of treatment you will need to ensure you don't get sick, even from grey water will be far more expensive than just keeping them separate.

3) For all of those systems, 15 gallons seems pretty light.

I'd like to get into this in more detail, maybe later if someone else doesn't pick it up before me.

For sizing the pressure requirement on a transfer pump from a river/lake to your tanks here is a rule of thumb (this assumes a 5 gal/min pump, and 1" hose):

- Take the static vertical lift in feet, i.e. the elevation of the tank minus the lake water level - allow yourself 15 feet at least.
- Take the total length of hose (say 50 feet)
- Multiply hose length by 5%
- Add static vertical lift to hose length * 5%

This example would be 5 gal/min @ 17.5 ft head.

Everything changes with the hose length and diameter, and the design flow.

I hope this helps.

 

[Carl2500]

I hope this helps.

Greatly... Thanks for the reply.

I'd love to hear some more input, I'll add a little more.

Alright so filtering the grey water is out.. Maybe I could have a separate tank for the hose on the outside of the truck, and if I need to, I could filter that water.

15 gallons is light, I figured I could get away with a smaller tank if I could get water more frequently by filtering it. Also it'll most likely just be me and a dog. Maybe a 20 gallon tank.

 

[Lynn]

One way you can conserve water is to use your grey water to flush the toilet.

Here's a pretty good resource for all things RV, with an emphasis on 'boondocking,' which is what the RV world calls roughing it. Lotsa things there for you to spend some time reading.

 

[mcgovski]

Tell us more about this water heater. I have been looking to replace the water heater in my camper because it sucks! I was going to tinker with possibly putting a bosch aqua star intended for household use, like 2-3 gpm unit instead of the small 6 gallon tank water heater I have now. Its a pain! Anyway, tell me more about your water heating system.
My camper has a 34 gallon fresh water tank and lasts around 4 days with my wife and I + 2 dogs.

 

[Carl2500]

Well first I'll admit, I really haven't done my homework on this part yet, so this is just the first thing that comes to mind.

Make a box out of sheetmetal, 1"X4"X6".

Put a threaded hose fitting on one corner, and then the opposite corner, for your inlet and outlet.

Put in a heating element, snaked up and down 3-4 times.

Then you'd need a water pressure switch to activate the heating element.

You could use a rheostat to adjust the temperature

 

[Lynn]

Make sure you test that design well. For instance, when I lived in Spain we had an older flash heater that was dangerous. If you happened to run the hot water for a while, turn the water off, then turn it back on again within a few minutes, the water would come out scalding-hot.

This was a commercial design that was in common use.

I'm not saying that you can't build a safe one, but you will need to do a lot of testing, in all conceivable operating situations, to ensure it's safe. It may not be so simple.

 

[Carl2500]

Thanks Lynn, I agree with you it'll need alot of testing before I'd trust something like that in my camper. I will definitely try to do more research on this tonight, and come up with some more information.

 

[RobinP]

Carl,

Water takes a lot of energy to heat. There is an electric solution out there, I think Scott had one in the back of his Tacoma. But that aside, you're going to need a good reserve of battery to heat water up, even if only for a quick and slightly more than luke-warm shower. The efficiency of a home-grown solution is probably not as good as a tested product, though don't let that stop you!

Consider going with a heat exchanger style that uses the hot water from your cooling system (yes the engine needs to run to heat the water), but at least the energy requirements are solved. I've seen these done home-made, and there are a number of products out there as well.

Another option would be an inline propane water heater.

 

[IH8RDS]

For you black water I would use one of these:

It makes it allot eaiser to remove the waste and dump it at the dump station.

 

[njtaco]

Water Heater

Check out this thread on water heater solutions...courtesy of Captain Coors.

 

[Desertdude]

A bit of info; I set up a system with these components:

Water Heater runs off 110 Inverter or 5/8" heater hose from the engine.

12v pump

Poly Tank

Deck shower faucets

1800 Watt inverter

All the water is filtered into the tank - Also carry a small pump if I want to fill and filter from a water source.

Two years running with no issues... (basic tank and fill line cleaning once a year)

I have a similar set up in the Tacoma with the Helton heat exchanger instead of the isotherm water heater/inverter.

Much simpler and can use an outside source for water in a collapsible bucket.

:::

 

[egn]

I'd like to have a setup similar to RV's, with a fresh, grey, and black water tank. I'd like to carry 15 gallons of fresh water. What size grey and black water tanks would be about right?

This really depends on how many persons you are and how long you want to be self-sufficient. 15 gal are a lot if you use it for drinking only. But if you use it for cooking, washing up, toilet, shower, ... it is not much.

You should check your daily use and then decide. Please keep in mind that most of the water is used for flush toilets and shower. Especially the normal flush toilets use up to about half a gal per use. This may add up to 2-3 gal/d and per person.

There are several alternatives to reduce this:

• grey water for flush
• vacuum toilet ( http://www.conrad-anderson.co.uk/sanitation/vacuumtoilet-conveniencefeature.htm )
• Envirolet VF ( http://www.envirolet.com/vf.html )
• use "external" toilet

Grey water for flushing is a possibility, but has the disadvantage that it may also smell very bad.

A vacuum toilet is much more expensive and also needs room.

Going "external" is the cheapest but also the most inconvinient.

Also if possible, I'd like to be able to pump water from a lake or river while camping, maybe into a separate holding tank, before it's filtered into the fresh water tank. That way I don't have to carry as much, and would always have good water around.

I use a similar system. I have two large raw water tanks with about 66 gal each. This tanks can be filled up with a pressured hose or by the use of a electrical water pump. One of those tanks can be selected to pump the water through a micron filter system into a smaller fresh water tank with about 25 gal. The fresh water tank is additionally treated by UV radiation.

Another option I was thinking, would be to just pump in the water to the grey water tank, and use a filter between that and the fresh water tank.

Though I haven't heard of people filtering the grey water tank back into the fresh water tank, so I'm not sure if it'd be recommended.

This is very bad idea. You may use grey water if it isn't contaminated by food for flushing the toilet. But you should never drink it, otherwise your blackwater holding tank will not be large enough.

For filters, I was thinking of making my own, using a .25 micron and .10 micron filter, with a few plastic pipe fittings. I've read that should take care of just about everything, and shouldn't cost too much.

Use a ready system otherwise you will run into problems. The system I use is good for about 15,000 gal of water if it isn't to much contaminated. I change the filter once a year and it doesn't cost much.

As far as other accessories, I was looking at a small tankless water heater. Again I may be able to make this myself. It's basically just an electric element placed in water. If not they're only about a 120 bucks anyway.

You should forget this. A domestic water heater that can deliver 2-3 l per minute with a raise of temperature of about 35 K needs a power of about 6 kW.

Were can you get that much power?

I use a Isotherm boiler with enough capacity for about two days. Normally you would connect it to your engine and get the heat for free when you drive. As I have an air cooled engine it is connected to diesel furnace. Sometimes I heat it electrically during driving because I have a 150 A/24 alternator.

If you have LPG than think about a compination of LPG furnace and boiler.

I'll need a system to monitor the level of each tank. Maybe something as simple as a single LED when it's full.

There are plenty of systems in the market available.

And finally I'll need a strong enough water pump, to push the water to everywhere it needs to go. I'm up for any suggestions on how much PSI, and which brands are good.

If you have no special requirements than a normal RV water pump will do. Remember, you have not a lot of water. The lower the water pressure, the less water will flow unused through the sink. We also don't use much pressure and when taking a shower we normally use not much more than about 3 gal per person.

Look what the commercial RV builders are doing. It is not necessary to reinvent the wheel.

 

[Desertdude]

Good point... In the desert where finding a water source out in the wilds is scarce, if your not careful, 20 gallons for two goes quite fast.

I also spent time testing how little water we could use per shower. By adding a water saver washer and cranking the pressure down on the pump - one person could shower with less than 3/4 gal if you were careful with usage.

Interesting toilet options here

 

[egn]

Interesting toilet options here

I used that system in my old motorhome. It is very popular in Europe.

The great advantage is that you don't much need additional water. One cassette with about 6 gal was good for about 2 days with 4 persons. BTW, we didn't use any chemicals to fight the odor. We used a special system that starts sucking air with a fan out of the cassette when the toilette is opened. This way you never have any odor inside the motorhome. This is a great system. And the oxygen provided helps good bacteria to break down the black water.

The disadvantage is that the one that discharges the cassettes has to live with the bad smell if the discharge station is not designed appropriately.

But beside that I find it is the best system for small motorhomes. We had two cassettes and with the tight net of service stations here in western europe it was never a problem.