Camper van water system

[TonyM]

I'm plumbing the water system for my campervan and made the following schematic to show the different modes it can operate. Although I'm an experienced DIYer, I've never tackled a plumbing job this complicated and I'd appreciate any advice before I actually do this.

Producing a large tank of hot water as needed is (perhaps) a unique feature, and using the pump to draw in water from streams, etc... might also be uncommon.

Normal operation using Tank 1 – B, F open
Normal operation using Tank 2 – C, F open
Filling Tank 1 from a water source – A, E open
Filling Tank 2 from a water source – A, D open
Heating Tank 1 by recycling water through heater – B, F, G open
Emptying all tanks – B, C, F, H open

All valves closed unless specified as open

Additional details: Vents, etc... are not included in the diagram. Tanks 1 & 2 are each 100L fresh water tanks located within the van, and the gray water tank is another 100L tank mounted below the van. The heater is a Truma Diesel heater which heats air in the van, but it also heats a 10L water tank within it. Water sources to fill campers typically are pressurized so there's no need to use a pump to fill them. However, I want to be able to draw water from sources like streams as well. By the way, I don't plan to drink any of this water -- it's just for washing and showering -- but instead plan on bottled water for drinking.

 

[Pudsey Bear]

That (to me) looks massively over complicated.

I had a fresh tank, outlet to a Shurflo pump, which fed the boiler and all the taps hot and cold, unless you have a special requirement I don't see why the extra complexity

 

[TonyM]

Thanks for your comment @Pudsey Bear -- if you have a way to provide the features I want in a simpler way, I'd be very interested. Those features are implied in my original post, but here's another way of listing them:

1) ability to use, fill 2 tanks (including from streams)
2) ability to fill one of those tanks with hot water
3) ability to empty all tanks

 

[Pudsey Bear]

Sorry I misread the OP, but I'm not sure how you would do all of that, it's never cropped up before that I know, I won't ask why as you have made a decision to go that way, as from streams We used to do that, but used a simple watering can, I expect you could utilise a secondary Shurflo pump to do it as well, but seriously good filtration would be needed as I didn't like the taste of dead sheep and cow crap in my water.

 

[wildebus]

Looking at the diagram, it is absolutely a solution. But a solution for a problem that doesn't exist.

BTW ... "Producing a tank of hot water as needed is (perhaps) a unique feature".... why is that unique? seems pretty normal to me or am I missing something?

 

[TonyM]

@wildebus I said "unique" because I am unaware of anyone recirculating water through a small campervan type water heater to heat a large (100L) tank of water. So I added the word "large" to my original post to hopefully help clear up that confusion.

The Truma combi does a good job of producing 10L of water as it also produces warm air to heat a motorhome — and this is fine for most situations. But if you want to produce larger amounts of hot water it becomes more difficult and introduces a lot of problems in terms of cost, weight, expense,… The Truma diesel heaters have a lot more capacity than is needed for a campervan so I woud think it could handle the recycling approach I mentioned. If you’re aware of someone else who had done that, I’d be very interested.

Thanks for your feedback on the diagram, it encourages me to move forward. I know that I can miss simple things, especially when doing something for the first time.

As far as it being a solution for a problem that doesn’t exist, well, all I can say is that it exists for me… unless you have a simpler solution that meets the features I listed in my response to Pudsey Bear

Thanks again

 

[Squiffy]

I'm plumbing the water system for my campervan and made the following schematic to show the different modes it can operate. Although I'm an experienced DIYer, I've never tackled a plumbing job this complicated and I'd appreciate any advice before I actually do this.

Producing a tank of hot water as needed is (perhaps) a unique feature, and using the pump to draw in water from streams, etc... might also be uncommon.

View attachment 5663

Normal operation using Tank 1 – B, F open
Normal operation using Tank 2 – C, F open
Filling Tank 1 from a water source – A, E open
Filling Tank 2 from a water source – A, D open
Heating Tank 1 by recycling water through heater – B, F, G open
Emptying all tanks – B, C, F, H open

All valves closed unless specified as open

Additional details: Vents, etc... are not included in the diagram. Tanks 1 & 2 are each 100L fresh water tanks located within the van, and the gray water tank is another 100L tank mounted below the van. The heater is a Truma Diesel heater which heats air in the van, but it also heats a 10L water tank within it. Water sources to fill campers typically are pressurized so there's no need to use a pump to fill them. However, I want to be able to draw water from sources like streams as well. By the way, I don't plan to drink any of this water -- it's just for washing and showering -- but instead plan on bottled water for drinking.

Hi Tony,
I have to agree with Pudsey and say that to me at least you have greatly over thought out your pluming system. I am not aware of the vehicle you are building but calling it a Campervan suggests its similar to a VW T 5/6, if this is the case two 100L Internal tanks would be taking up one hell of the available volume. Unless you intend to wild camp in outer Mongolia or the wilds of Scotland the second tank for wild water would be superfluous and I personally never drink water from any tank including the main fresh water tank unless the water has been boiled any way plus water is readily available all over the UK and continent. Not sure if you are a seasoned traveller.
My other comment would be because of the complexity of the water system it would also be open to many joints that in turn could be prone to leaks even when the joints were produced correctly. If I would be in favour of simplifying the whole system. Phil

 

[wildebus]

@wildebus I said "unique" because I am unaware of anyone recirculating water through a small campervan type water heater to heat a large (100L) tank of water. So I added the word "large" to my original post to hopefully help clear up that confusion.

The Truma combi does a good job of producing 10L of water as it also produces warm air to heat a motorhome — and this is fine for most situations. But if you want to produce larger amounts of hot water it becomes more difficult and introduces a lot of problems in terms of cost, weight, expense,… The Truma diesel heaters have a lot more capacity than is needed for a campervan so I woud think it could handle the recycling approach I mentioned. If you’re aware of someone else who had done that, I’d be very interested.

Thanks for your feedback on the diagram, it encourages me to move forward. I know that I can miss simple things, especially when doing something for the first time.

As far as it being a solution for a problem that doesn’t exist, well, all I can say is that it exists for me… unless you have a simpler solution that meets the features I listed in my response to Pudsey Bear

Thanks again

Ref the Hot Water ... I see no need to having 100L of hot water - do you have a hot tub in your Camper?
The typical Motorhome tends to have around a 10L hot water capacity. That coincidentally is around what a nice shower (mixed with cold water) would use, so it a pretty good match.
The chances are the 10L capacity found is more than just a lucky happenstance. I cannot see why anyone (hot tubbing aside) would need 100L of heated water. What will you be using this for exactly?
Now there is an important safety aspect here .... if you maintain a tank of warmish water, you run the risk of it being a nice breeding ground for legionalla. Having a small tank of around 10L means the water tends to get heated to a level that would kill the bug and then drained down in use. That cycle is pretty safe. a 100L tank of water takes a lot of energy to heat (my 10L tank would have the 850W heater on for 1 hour (I've timed it) to get it to 60C - so 850Wh of power. Your 100L tank will need close to 10kWh of energy to heat to a safe level, and then you will need to maintain it above a certain temp (using more power) or let it go cold and start again (another 10kWh please).
Are you aware of this very real issue and how do you intend to make sure you eliminate it? where is all this energy coming from you will need to maintain the water temp?


Your diagram kind of reminded me of the Hot Water setup I did in a previous house, where I could use various manual valves and automatic thermostatic mixing valves to isolate and mix different supplies from a Gas Boiler, Mains Water and Solar Heated water to the taps to maximize the best energy use to supply hot water. Worked very well but applying that logic to any kind of Campervan or Motorhome - nah, no way. just no point whatsover.

Is it a problem that exists? Sorry, I don't think it does even though you imagine it does, but good luck with the design although I cannot see it being implemented for so many different reasons.

 

[Pudsey Bear]

I think if we knew the why it might promote the how.

 

[TonyM]

@Squiffy thanks for your comments. I too am in favor of making things as simple as possible. But as others smarter than I have said, "not simpler" So, if you can describe for me a simpler way to achieve the goals Ive listed, I'm eager for the help.

As to why I want what I want, that's another story. Regarding the space that two 100L tanks would take, I've already worked that out in great detail and it's not a problem.

 

[TonyM]

@wildebus thanks for these additional comments. I can now see that I misinterpreted you when you wrote that it was “absolutely a solution” — I now believe you are really saying that it is unworkable and you wouldn’t recommend it. Although not what I wanted to hear, that’s why I ask others for help, so thanks again.

It seems those responding so far are mostly focused on why I have the goals I’ve described rather than how to achieve those goals. As I wrote above, that’s another question and if everyone really wants we could schedule a long discussion about that in another forum. I came to this forum just to learn how to solve technical problems from those who have experience doing related things.

Maybe someone has experience that can help me do things better.

 

[Squiffy]

Tony your plan is definitely workable, I've done many a plumbing job on motorhomes and campervans and looking at your plan it is a workable solution to how you require it to work if that's what you require. The comments I've made were meant to be helpful obviously I mis understand your post. Phil

 

[TonyM]

@Squiffy thanks, this is encouraging. I've worked with a lot of valves for house and sprinkler systems, but I've never worked with a system of valves like this that have to work together in different modes, particularly with a pump. Also, the pump recycling part is intriguing to me. Of course, that's why I went to the trouble of drawing the diagram. Thanks again.

 

[wildebus]

@wildebus thanks for these additional comments. I can now see that I misinterpreted you when you wrote that it was “absolutely a solution” — I now believe you are really saying that it is unworkable and you wouldn’t recommend it. Although not what I wanted to hear, that’s why I ask others for help, so thanks again.

It seems those responding so far are mostly focused on why I have the goals I’ve described rather than how to achieve those goals. As I wrote above, that’s another question and if everyone really wants we could schedule a long discussion about that in another forum. I came to this forum just to learn how to solve technical problems from those who have experience doing related things.

Maybe someone has experience that can help me do things better.

In the confines of a campervan, "unworkable" is probably fair in what I am saying, although I would have preferred the word "unfeasible" (although they have the same meaning in a dictionary), or maybe "unpracticable" could be another approprate "un-" word? All have the same meaning end of the day.

I am still interested in the WHY regarding having a 100L Hot Water tank in a Campervan. I honestly see no reason in a hot water tank of that capacity. You clearly have a very specific need which you don't want to share for whatever reason, so any readers have to make assumptions - wrong assumptions they maybe (who knows!?), but blame the lack of information provided, not the replier.
Now that is a large amount of hot water, and without a plumbed in mains water supply (which you obviously don't have in a van) to replenish as you draw, the hot water use must surely be pretty sporadic, which takes me back to my point of the safety requirement of maintaining a large (especially in Campervan terms) body of water at sufficiently high temperature ready for future use.

To heat 1 litre of water one degree will take the same energy no matter if you are heating to use now or heating to store for later use.
Given there will be the need to expend a lot of energy in water heating, if I had a need for a large volume of hot water but with sporadic use, I would be more inclined to look at high-power instant hot water systems than a storage tank. (Going back to the 'plumbing in a house' type comments, the use of hot water cylinders for stored water is reducing all the time and Combi boilers are more the typical installation and the reasons for that would apply equally well in a campervan). Is that option suitable for your needs? Who knows as your needs are classified secret

So on that tact, why store lots of Hot Water for future use when you can heat it on demand even in a campervan? I said I had a 850W Water Heater? That heater (a Truma Ultrastor) also has a Gas heating ability and if I ran the two together, I would be close to running out of water in the 100L fresh tank before the water ran cold. In my previous camper, I had a 10L water heater again, but that was a 2kW Electric Heater, usually used (and described as) an "Instant Hot Water Heater". You could get a 3kW or larger one of those in electric, or as a 'Instant' gas water heaters (like the old 'Ascots' used to see over the kitchen sink but bigger and more powerful), to get a faster/hotter water draw.
Seeing we don't know the use of all this hot water, we don't know the temperature it needs to be used at. Is it for a Hot Tub? Do you have a Jucuzzi Bath in the back? Tropical Fish tanks? Campervan-cum-Self-contained Car Valeter? (maybe Boat Valet so you are drawing water from a river a lot?)


End of the day, if you heat on demand, or heat to store, it is the same energy (ignoring all the losses you get when you need to compensate for heat loss on a hot water tank) and the only reason why a 100L Hot Water tank may be considered "unique" in a campervan is no one blooming needs one! Fitting a ski-jump in a Morelo Gin Palace would also be unique (but I bet some owners would like to).

 

[TonyM]

As I wrote above, that’s another question and if everyone really wants we could schedule a long discussion about that in another forum.

@wildebus not sure why you'd think I'm trying to keep secrets when I offered to have a long discussion about it? But thanks for the entertaining post!

 

[wildebus]

@wildebus not sure why you'd think I'm trying to keep secrets when I offered to have a long discussion about it? But thanks for the entertaining post!

So tell us WHY you need 100L Hot Water Tank?
"that’s another question and if everyone really wants we could schedule a long discussion about that in another forum"

Who wants a long discussion about your Hot Tub Habits or whatever it is. I sure as hell don't. just say WHY you need that volume of hot water.

 

[TonyM]

@wildebus let me know when and how you want to schedule the discussion

 

[wildebus]

@wildebus let me know when and how you want to schedule the discussion

sorry, but did you not read the "I sure as hell don't".
If not, schedule a meeting with my PA at www.iwouldratherpokemyeyesoutthendiscussrandompeopleshotwaterneeds.com

 

[Squiffy]

Hmmmm, think we may have come to the end of this discussion. Phil

 

[wildebus]

Hmmmm, think we may have come to the end of this discussion. Phil

not at all.
If you want a long discussion to learn why someone wants a big watertank, go for it