Fresh Water Tank Venting

[Biscuitsjam]

This is probably a silly question, but I have spent a lot of hours reading and haven't found a satisfactory answer yet.

I have two 30-gallon fresh water tanks, not plumbed yet. They are sitting over the engine compartment, one on each side of the bus, just under the bed in the back.

I want to install a city water inlet on the side of the bus. It will be about the height of the bottom of the fresh water tanks.

Tank vents are usually integrated into the gravity fill cap. However, the tanks are too high to put a gravity fill on the outside of the bus... I want a gravity fill option, and it would make more sense to do it inside.

So, here are my questions:
1. If I put the gravity fill (with vent) inside the bus, do I need to worry about water sloshing out while driving? Or if I overfill with city water?

2. If I use a vent not integrated with the gravity fill, what should I use? Should I try to vent to the roof, wall, or floor? Do I need to worry about bugs, bacteria, or particulates getting through my vent line?

[Danjo]

I found myself not able to do a gravity feed. At first I was bummed, but then I thought, what, you gonna fill with buckets? So I looked for a diverter valve so I could plumb house and tank water to the same connection. After not finding one, I used two municipal water connectors and a couple ball valves to make it work. The overflow is the vent. It’ is PEX aNd exits through the floor

[Danjo]

Get a faucet screen and jam it into the end of the pipe to keep bugs out

[TheArgobus]

The vent at the fill port also has a dual purpose of letting you know when the tank is full (when water starts coming out, you know it's full). You could also just fill until water starts coming out of the fill port... but that would get messy real fast, especially inside. How will you know the tanks are full? (shameless self promotion plug: you can use a liquid level sensor, arduino, and an LED bulb (https://www.skoolie.net/forums/f27/t...tml#post383445)





If I were in your shoes, I'd figure out a way to put the fill port/vent combo on the outside, even if it meant getting a step ladder (or installing rungs on the outside). I'd really dislike bringing a fresh water hose inside the bus because I'm too messy.


If I absolutely had to put the fill port inside, I'd install it in such a way that it faces downward, not sideways, and the water would go straight down into the tank. Maybe underneath the cushions? I'd install the vent elsewhere on the tank, and have that vent simply go out the wall. This would have the benefit of letting you know the tanks are full (you could hear the water gushing out the vent and hitting the ground before it rises up to the fill port and spills inside).


You don't have to worry about bugs and insects crawling their way in, so long as you have a fine mesh screen over the vent opening. I'm new to skoolies, but not new with sailboats, and in the 9 years I owned my 35 footer (including living on it full time), I never once noticed an issue with bugs or algea or anything making their way into the tank. If it's just fresh water, it's fine.

[Stngllhm]

I would second if at all possible have your fill port out side. Dragging a hose inside will open a hole host of issues. If only option it could be manageable but a pain.

[Biscuitsjam]

My thoughts right now...

1. I install a city water inlet (no vent) on the outside of the bus with a check valve on the line.

2. I put a 3-way valve on the city water so that it can either fill the tanks or can bypass the tanks and pump.

3. I install a ventless gravity fill inlet near the tanks in the bedroom inside the bus.

4. I install a vent from the top of the water tanks that runs to the side or rear of the bus, with a screen over the end of it.

[Danjo]

Why do you feel like you need gravity fill?

[Biscuitsjam]

I'm not too concerned with whether or not I have a gravity fill - I'm more concerned with where to put the vent for the fresh water tank. The vent is typically integrated into the gravity fill inlet on the outer wall of the bus, but I don't feel that it makes sense to put a gravity fill outside since I would have to make it too high to reasonably use.

[TheArgobus]

If it’s just a vent, run a 1/4” line to anywhere outside the bus—wherever is most convenient—so long as it’s at least a few feet above the top of the tank. The simplest solution would be to just run the line straight out of the wall, wrap the end in mesh, and secure it facing downward/backward so rain water doesn’t get in.

[Oscar1]

Originally Posted by Biscuitsjam

This is probably a silly question, but I have spent a lot of hours reading and haven't found a satisfactory answer yet.

I have two 30-gallon fresh water tanks, not plumbed yet. They are sitting over the engine compartment, one on each side of the bus, just under the bed in the back.

I want to install a city water inlet on the side of the bus. It will be about the height of the bottom of the fresh water tanks.

Tank vents are usually integrated into the gravity fill cap. However, the tanks are too high to put a gravity fill on the outside of the bus... I want a gravity fill option, and it would make more sense to do it inside.

So, here are my questions:
1. If I put the gravity fill (with vent) inside the bus, do I need to worry about water sloshing out while driving? Or if I overfill with city water?

2. If I use a vent not integrated with the gravity fill, what should I use? Should I try to vent to the roof, wall, or floor? Do I need to worry about bugs, bacteria, or particulates getting through my vent line?

Yes you could have a chance of some spillage inside with the vent there with the filler. The filler cap well secured should prevent any splashing from the filler hose. On my boat all the integrated vents on the fillers were sealed at the factory and independant vents were added. Maybe look at some nice marine thru hull vents and just go out the sidewall. They have very fine bug screens in them as well. Be aware that they can become clogged with spider nesting, I have had that happen but was able to clear them out with compressed air.

[Danjo]

My vent is a 1/2” FPT port on the top of the tank, plumbed with 1/2” PEX routed through a hole In the floor.

[Oscar1]

Originally Posted by Oscar1

Yes you could have a chance of some spillage inside with the vent there with the filler. The filler cap well secured should prevent any splashing from the filler hose. On my boat all the integrated vents on the fillers were sealed at the factory and independant vents were added. Maybe look at some nice marine thru hull vents and just go out the sidewall. They have very fine bug screens in them as well. Be aware that they can become clogged with spider nesting, I have had that happen but was able to clear them out with compressed air.

A few styles to look at

[Doktari]

I was thinking of running my freshwater tank overflow/vent into my graywater bucket ( there’s no space for a graywater tank in a Microbird). But I could drill a 3/8” hole and run it out the side wall of the bus?
Who uses a pressure regulator when hooking up to a water supply? I’m so used to setting up for boondocking I almost forgot to think about what would happen if I hook up to a faucet. I dont want to pressurize my water tank with much pressure. It doesn’t look very strong. My overflow would need a plug if I hook up to a pressurized water line.

[ol trunt]

Valve city water past the water tank and do use a pressure limiter. Gravity fill your water tank with a vent/overflow going outside. Put a screen in the vent to keep critters out.
Jack

[JackE]

One of these may work for you as an outside vent cover. I plan on using one for my grey/black vent cover up high on the wall. I don't want to drill a hole in my perfectly non leaking roof!

https://www.amazon.com/dp/B006R5LND0...v_ov_lig_dp_it

https://www.amazon.com/dp/B073ZCHCCS...v_ov_lig_dp_it