Propane System Design Guide for DIY Van Conversion

Propane-System-DIY-Van-Conversion-Heading-1920

Propane System Design Guide for DIY Van Conversion

Welcome to our Propane System Design Guide! We personally decided to go with propane in our van because propane packs WAY more energy than a battery: for example, our BBQ tank gives us two months of cooking and hot showers before we have to refill it, while a battery would have to be recharged after only a few hours and would require costly upgrades just to make it work… For full time vanlife like we’re doing, it’s a no brainer. In the following guide, we will build our knowledge so we can design and build a safe propane system. Keep reading!

LAST UPDATE: APRIL 2020

Disclosure: This post contains affiliate links, which means that if you click a product link and buy anything from the merchant (Amazon, eBay, etc.) we will receive a commission fee. The price you pay remains the same, affiliate link or not.

Portrait

1- Campervan Propane System In A Nutshell

The Atwood range, hot shower and Propex heater are appliances that run on propane in our van:

1.1- Propane System Diagram

Hover your mouse on components to learn more and click to follow the link!
Tap on components to learn more!

1.2- Items List

ComponentDescriptionQuantityBuy Link
MAIN
Propane TankSee “Propane Tank” section1Amazon
Hose: Acme x 1/4″ Male NPT (1 feet)Propane tank to regulator1Amazon
Regulator: Two Stage, 11 W.C.It’s an horizontal regulator, so it should be horizontal!1Amazon
Elbow: 3/8″ Flare Male x 3/8″ MPTWe used an elbow so the regulator fits into the vented locker.1Amazon
Hose: 3/8″ Flare Female (both sides)Regulator to Bulkhead Union1Amazon
Bulkhead Union Fitting: 3/8″ Flare Male (both sides)This is to go through the vented locker while keeping a tight seal.1Amazon
Swivel: 3/8″ Female Flare (both sides)This is to connect the bulkhead fitting to a cross (or a tee).1Amazon
Cross: 3/8″ Male Flare (all sides)Use this if you have 3 appliances to connect.As RequiredAmazon
Tee: 3/8″ Male Flare (all sides)Use this if you have 2 appliances to connect.Amazon
NoneUse none if you only have 1 appliance to connect. (and delete the Swivel 3/8″ Female Flare as well).N/A
Solenoid Shut Off Valve 12V
Solenoid, 12VTo open/close the propane remotely1eBay
Push-Button SwitchTo energize the solenoid1Amazon
PigtailTo wire the push-button switch1Amazon
90 Degrees FittingSo the regulator / solenoid assembly fit in the locker1Amazon
MISC: wire, terminal rings, closed end terminals, quick disconnects, silicone…
Low Pressure Gauge
Low Pressure Gauge 15″ WCOur system nominal pressure is 11″ WC, so we chose a gauge that goes up to 15″ WC.1Amazon
Tee, 1/4″ x 1/4″ x 1/4″ NPT FemaleTo add a new port for the gauge…1Amazon
3/8″ Flare Female to 1/4″ MPTTo connect to the 3/8″ flared cross and bulkhead fitting2Amazon
1 lb Bottle Adapter (High-Pressure) -Optional-
Tee: 1/4″ FPT x 1/4″ FPT x 1/4″ MPTThis is to split the line coming from the tank into two lines: one going to the regulator (low pressure), one going to the 1 lb bottle adapter (high-pressure).1Amazon
Adapter: 1/4 MPT x 1″-20 Male 1Amazon
Extension Hose: 1″-20 Female to 1″-20 Male 1Amazon
Eccotemp Hot shower (Buy on Amazon)
Gas Valve: 1/2 NPT to 3/8 Flare MaleThis valve connects directly to the Eccotemp.1Amazon
Flexible Copper Tubing: 3/8″ O.D. Length As RequiredAmazon
Flare Nut: 3/8″ O.D.1 side connected to the gas valve, 1 side to the cross.2Amazon
Propex HS2000 Heater (dealer locator)
Flexible Copper Tubing: 1/4″ O.D.The Propex requires 1/4″ O.D. per manual!Length As RequiredAmazon
Flare Nut: 1/4″ O.D. 1Amazon
Reducer: 3/8″ Female Flare to 1/4″ Male FlareThis is to connect the 1/4″ copper tubing the to cross.1Amazon
 Note that the Propex HS2000 includes a compression nut to connect the 1/4″ line to it.  
Atwood Range (Buy on Amazon)
Flexible Copper Tubing: 3/8″ O.D. Length As RequiredAmazon
Flare Nut: 3/8″ O.D. 4Amazon
Gas Valve: 3/8″ Flare Male (both sides) 1Amazon

2- The cost of going all electric (no propane)

2.1- Propane Pros & Cons

Working on it. Coming soon!
Sketchy Clock

2.2- All electric VS propane cost comparison

Working on it. Coming soon!
Sketchy Clock

3.1- What size?

Choosing the right propane tank size totally depends on what appliances you run and what autonomy you want (days/months with no refill). As a rough guideline and to help you make a decision, here is our usage living full-time in the van:

  • We don’t know the exact consumption of each appliance, but we know that using our Atwood Range every day (oven & stove) and using our  Eccotemp shower every other day or so, our 20 pound propane tank last roughly 2 months.
  • We don’t use our Propex heater much (we prefer to use our Webasto Air Top 2000), but the consumption is 1 pound of propane every 3 hours (remember it cycles though, it’s not running full-time). Our autonomy definitely shrink a lot if we use the Propex.

3.2- Tank Types

3.2.1- Disposable bottle

The 1 pound disposable bottles are OK for occasional camping trips, but expensive and not environmentally friendly in the long run…

Here’s a tip: Any appliance that normally requires small camping propane bottle (camp stove, Mr Heater Buddy, etc.) can be used with a larger tank (5, 11, 20 pound), thanks to the following adapter. One side connects directly to the propane tank, the other side connects directly to the appliance. No regulator needed. It’s much more economical!

3.2.2- Steel Propane Tank

Also known as “BBQ Tank”… no explanation needed! OK, here’s a picture just in case…

Propane Tank 20 Pound Steel

They’re easy to find in 5, 11 or 20 pound (or more). Here are some common specifications:

* Note that tanks are not filled to their max capacity; this is to leave room for vapor expansion. For example, a 20 pound tank will generally be filled to approx 18 pound.

** Vertical tanks must not be installed horizontally. If the orientation is not correct liquid propane will be collected instead of vapor (LP gas).

DescriptionCapacity (lb)Capacity (gal)Diameter (in)Height (in)Empty Weight (lb)Full Weight (lb)Buy Link
5 Pound Vertical**5*1.29121015Amazon
11 Pound Vertical11*2.612.212.41425Amazon
11 Pound Vertical11*2.69.25171425Amazon
20 Pound Vertical20*4.612.2517.751838Amazon
DescriptionDiameter (in)Height (in)Buy Link
5 Pound Vertical**912Amazon
11 Pound Vertical12.212.4Amazon
11 Pound Vertical9.2517Amazon
20 Pound Vertical12.2517.75Amazon

3.2.3- Aluminum Propane Tank

“BBQ Tanks” are also available in aluminum with the following characteristics:

  • Lighter than steel (approximately 3 pounds lighter for 2.6 gallon capacity, 5 pounds lighter for 4.6 gallon capacity)
  • Does not rust
  • Does not sparks if ruptured
  • Does not have to be painted
  • More expensive

They’re easy to find in 10 or 20 pound. Here are some common specifications:

* Vertical tanks must not be installed horizontally. If the orientation is not correct liquid propane will be collected instead of vapor (LP gas).

DescriptionCapacity (lb)Capacity (gal)Diameter (in)Height (in)Empty Weight (lb)Full Weight (lb)Buy Link
10 Pound Vertical102.310.516.49.519Amazon
20 Pound Vertical204.612.320.71332eBay
DescriptionDiameter (in)Height (in)Buy Link
10 Pound Vertical10.516.4Amazon
20 Pound Vertical12.320.7eBay

3.2.4- Composite (Fiberglass) Propane Tank

Here’s a fancy option to impress your neighbors:

  • Lighter than steel and aluminum
  • See-through (no guesswork to know when to refill)
  • Does not rust
  • DOT approved for US and Canada
  • Must be re-certified every 5 years (from the date of manufacture, not from the purchase date)
  • Because it’s not common, some people reported that it makes it harder to re-fill or re-certify.

They’re easy to find in 11, 17 or 22 pound. Here are some common specifications:

* Vertical tanks must not be installed horizontally. If the orientation is not correct liquid propane will be collected instead of vapor (LP gas).

DescriptionCapacity (lb)Capacity (gal)Diameter (in)Height (in)Empty Weight (lb)Full Weight (lb)Buy Link
11 Pound Vertical1112.61215.18.619eBay
17 Pound Vertical1741218.310.227eBay
22 Pound Vertical225.241222.51233Amazon
DescriptionDiameter (in)Height (in)Buy Link
11 Pound Vertical1215.1eBay
17 Pound Vertical1218.3eBay
22 Pound Vertical1222.5Amazon

3.2.5- Underbody Propane Tank

  • Underbody tanks are either built to ASME or DOT standard. Tanks built to ASME specification don’t required to be re-certified, as opposed to DOT that must be re-certified after 10 years initially then every 5 years. Therefore, if we were to install an underbody tank, we would choose a tank built to ASME standard…
  • On a side note: portable tanks (such as BBQ tanks) are all built to DOT standard, because the ASME tanks are designed to be stationary and cannot be transported when full.
  • Make sure to choose a size that will fit into an underbody cavity. Sorry we can’t help with that because we haven’t installed one ourselves, but here is a legit installation write-up on a Ford Transit:  www.fordtransitusaforum.com/170338-post42.html

* ASME tanks don’t require to be re-certified (permanent).

DescriptionCapacity (gal)Diameter (in)Length (in)Empty Weight (lb)Buy Link
7.9 gallon ASME7.9103252Campervan-HQ
11.2 gallon ASME11.28123272Campervan-HQ
16.3 gallon ASME16.36144081Campervan-HQ
DescriptionDiameter (in)Length (in)Buy Link
7.9 gallon ASME1032Campervan-HQ
11.2 gallon ASME1232Campervan-HQ
16.3 gallon ASME1440Campervan-HQ

4- Vented Tank Locker

The pressure inside a tank increases with higher temperature and/or elevation. Too much pressure can also be the result of overfilling the tank. If the pressure becomes too high for the tank’s capacity, excessive pressure will be released through the pressure relief valve. Note that even if the tank’s main valve is completely shut, the pressure relief valve can still release pressure.

Because of the greenhouse effect and because of the change in elevation (when driving), a tank located inside a van is subject to large pressure variation. That’s why we built a vented propane locker to store our propane tank in our van. If the tank was to release pressure, it would be evacuated outside the van!

What about the laws? When transporting a propane tank inside a vehicle, Canadian laws mention that it must be vented (cracked windows or partially opened trunk). We couldn’t find such mention in the USA laws, but there are rumors California laws mention it too (please tell us if you know where to find such a mention). Law or not, for us it just made sense to build a vented propane locker!

5- Regulator

A tank delivers the propane at high pressure (from 100 up to 315 psi depending on temperature and elevation). However most appliances require low pressure (a.k.a “LP”): 11 Water Column (or 11 W.C.) pressure is the norm in RV systems (11 W.C. = 0.4 PSI). The role of the regulator is to deliver a stable 11 W.C. pressure to the appliances.

5.1- Single Stage Regulator

A single stage regulator reduces the pressure to 11 W.C. in one step. They’re more compact than two stage regulator.

5.2- Two Stage Regulator

A two stage regulator reduces the pressure in two steps. Compared to one stage regulators, they are better at delivering constant 11 W.C. pressure with temperature changes and as the tank pressure declines. A single stage regulator is probably fine in most case, except our Propex HS2000 heater requires a two stage regulator so this is what we went with. Two stage regulators are not significantly more expensive than one stage, so it’s not a bad idea to choose a two stage regulator…

5.3- High Pressure (No Regulator)

Appliances that use small 1 pound bottles have their own built-in regulator. Camping stove, Mr Buddy heater, Mr Buddy BOSS shower, among others work with high pressure. They can be hooked to a full-size propane tank (5#, 11#, 20#, etc.) with an adapter:

6.1- Tubing Material

It is not recommended to use flexible (rubber) hoses as they are not approved for interior permanent installation (they are approved for marine applications, but that’s a different story). Don’t use them outside too, as critters like to chew on them!

Use flexible copper tubing with flared fittings. It’s resistant to vibration, sharp edges and don’t deteriorate with time (as opposed to rubber hose).

6.2- Tubing Size

It’s important to select the correct tubing diameter to prevent pressure drop. The correct diameter depends on:

  • Max Pressure Drop Acceptable (1/2 W.C. drop is the norm)
  • System Pressure (hint: it’s 11 W.C. for most RV appliances such as the Atwood Range, Propex Heater, Eccotemp Hot Shower, etc)
  • Length of tubing (varies according to your installation)
  • Capacity (BTU/hours)

 

Capacity (BTU/hrs) in function of Tubing Length and Outside Diameter for Flexible Copper Tubing at a pressure of 11 W.C:

Copper Tubing O.D. (in)Length of tubing between the regulator and the appliance (feet)
102030
3/849,000 BTU/hrs34,000 BTU/hrs27,000 BTU/hrs
1/2110,000 BTU/hrs76,000 BTU/hrs61,000 BTU/hrs

 

  • The Atwood Range is max 32,000 BTU/hrs (all 3 burners and over working simultaneously), so we’re allowed 20 feet of 3/8″ O.D. copper tubing.
  • The Eccotemp shower is rated 37,000 BTU/hrs, so we’re allowed about 15 feet of 3/8″ O.D. copper tubing.
  • Bottom word: we will use 3/8″ O.D. copper tubing all over! It should be alright for most van installation…

6.3- Tubing Bending

Bending the tubing by hand is “OK” (but not ideal) for light bends, but it will most likely create “kinks” for anything more than 45 degrees (kinks are bad because it restricts the flow of gas). It can be prevented, you guessed it, by using the proper tool for the job:

7.1- Flared connections

Flared connection is the preferred type and it’s standard in North-America. Flared fittings have a 45 degrees chamfer (male or female) that seal the deal. They do not requires thread sealant or tape.

Flare-vs-Non-Flare-Fittings

To make a flared connection with copper tubing:

1- Cut the copper tubing with a Tubing Cutter:
Tubing Cutter
2- Insert the Flare Nut into the tubing:

Note: Select the appropriate flare nut according to the tubing O.D.; for example use 3/8" O.D. flare nut with 3/8" O.D. copper tubing.

3- Form the flange using a Flaring Tool:
Flaring Tool

Note: First make sure the cut it deburred; any burrs that become compressed will leak.

4- Voilà!
Flared Tubing

It should look like this!

7.2- Pipe (NPT) connetions

Some appliances or regulators comes with NPT connection. NPT fittings don’t have a 45 degrees chamfer (see “Not Flared” picture). They require thread sealant (a.k.a. “DOPE”, Buy on Amazon) or yellow tape (Buy on Amazon). Do NOT use white teflon tape! It’s made for water system, so it will leak gas as it’s not thick enough.

Flare-vs-Non-Flare-Fittings

7.3- Compression fittings with olive

These are NOT common in North-America and should be avoided! They’re mostly designed for liquid or compressed air (not gas). Note that the Propex HS2000 comes with this type of connection; that’s the only place we have one in our system…

1920px-Compression_fitting_isolating_valve_15mm_screwdriver_turn

8.1- Manual valve

For safety sake, it is recommended to install a valve (easily accessible) every time a propane line split to connect to an appliance.

8.2- Solenoid valve

A solenoid shut off valve can be added to propane system, near the tank, to easily shut the propane OFF when not using it. The solenoid valve is OFF at all times (“normally closed”), but turns ON (open) when it’s energized with 12V. As soon as the 12V is removed, the valve shuts OFF. When energized (ON), a solenoid draw a current of about 1 amp (depending on brand/model). It’s the main inconvenience of the solenoid valve: you need constant electrical power to get propane. But it’s actually meant to be like that; in case of an accident the electrical power would probably go OFF. It’s a safety feature.

Most solenoid valve are meant to be installed on the low pressure side of the propane system; that is after the regulator. We like the Century Fuel’s AFC-151R solenoid shut off valve because it can take up to 312 PSI, so it can be installed on the high pressure side (before the regulator) as well and its 1/4 MPT port fits directly into the inlet of our propane regulator:

READ THIS: Solenoids needs constant power to remain ON (open) and therefore they get really hot to the touch. They relie on propane flow to cool down, so leaving it ON without using propane will make them even hotter. We get a lot of emails about that… So yeah, it is normal for the solenoid to get very hot!

9- Pressure Gauge

It’s not mandatory by any means, but a pressure gauge installed in the low pressure side (after the regulator) of the system can be a useful thing: you can quickly tell if your regulator is delivering the correct pressure. Indeed, we had a regulator that failed one day (Camco brand) and we spent hours and hours troubleshooting our Propex heater thinking it was faulty… we installed that gauge since then:

Note: Always take a reading when at least one appliance is running (dynamic pressure)! Static pressure (no appliance running) will always reads higher than 11 WC…

 

10.1- Checking for leaks

Propane manufacturers add a distinctive skunk or rotten egg smell to propane so you are able to detect right away if there is a major leak. That being said, after installing your propane system, you MUST validate that there are no leaks. To do so, pressurize your system (turn all the valves / solenoid ON) and apply soapy water to each fitting; in other words, on every connections in your system. If there is a leak, you will see bubbles forming.

Propane System Installation Camper Van Conversion (22)

10.2- Gas Detector

Because we turn ON propane only temporarily for short period of time (using our solenoid), we personally don’t have a gas detector. However here’s an option if it makes you feel better:

  • This is to detect un-burned gas/propane; in other words, to detect leaks in your system.
  • Mount it near the floor (because gas/propane is heavier than air, it will collect near the floor).

10.3- Carbon monoxide alarm

We initially had a carbon monoxide alarm without digital reading, so nothing was telling us that it actually worked… We upgraded for this one for peace of mind:

  • This is to detect carbon monoxide (CO), resulting from propane combustion. 
  • Mount it near the ceiling or floor (because carbon monoxide is almost the same density as air, it will disperse evenly throughout the air in a room.)

10.4- Smoke Detector

The first Alert P1010 smoke detector is tiny and blend perfectly with the decor in our van:

  • Mount it near the ceiling.

11.1- Wireless sensor for smartphone

Our propane tank being located into the locker, it’s not exactly convenient to check the propane level. Fortunately we stumble upon the Mopeka TankCheck Sensor (Buy on Amazon): this neat device allows to monitor the level of propane from our smartphone. Nice!

11.2- Tank monitoring for Simarine Pico

We personally use the Simarine Pico to monitor the battery bank (%, solar input, etc), tank level (fresh, grey, Nature’s Head) & temperatures (in, out, fridge, battery, etc). It is possible to add propane tank level with the appropriate sensors.

Sensor for vertical tank

Vertical tanks don't have provision to add a sensor, but this sensor attaches magnetically to the bottom of a steel tank and makes it possible to read the level of the tank. Note that you must purchase the sensor AND the pre-processor:

Sensor for underbody tank

The ASME Manchester tanks that we recommend have provision for a level sensor. The sensor output is resistance (not voltage), which can be read by a Simarine module:

12.1- Vented Propane Locker Build

We mentioned earlier that propane might escape from the propane tank from the safety relief valve. This propane has to go somewhere: outside the van sounds about right. To achieve that, we built a sealed box that is vented through the floor with the lid on top (propane is heavier than air). We did not come up with this, this is what marine regulation asks for (some info here). Here is how it goes:

First of all, here are the dimensions for a few common propane tanks:

Propane Tank Dimensions

DESCRIPTIONSIZEDIAMETERHEIGHT
WORTHINGTON TANK
Steel, Vertical20 lbs12.25in17.75in
Aluminum, Vertical20 lbs12.25in20.6in
MANCHESTER TANK
Steel, Vertical20 lbs12.16in17.56in
Aluminum, Vertical20 lbs12.28in20.7in

And here are the interior dimensions of our propane locker:

Propane-locker-3D-interior-dimensions

We won’t go into the box fabrication details, but let’s just say that the cuts should be perfectly straight to have a good seal! All the edges of the box are glued together; this should seal the deal, but just to make sure, we also applied silicone on all edges inside the box:

Propane-System-Installation-Camper-Van-Conversion-(19)

We first checked that the propane locker would fit. To clear the aluminum nose stair, we raised the locker with 1/8″ thick MLV leftover we had handy:

Propane-System-Installation-Camper-Van-Conversion-(3)

We now have to make a hole in the floor. We want that hole to be sealed; if we ever have a water spill we don’t want water to ingress in between the layers of our floor.

We drilled it using a 1″-5/8 diameter hole saw (Buy on Amazon):

Propane System Installation Camper Van Conversion (8)
It's a drill.
Propane System Installation Camper Van Conversion (9)
It's a hole.

As usual, we must now sand the bare metal edges and apply primer + paint + clearcoat; this is to prevent rust (we went to an auto parts shop and they prepared paint that matches the color of our van). No picture sorry, so here is a dancing banana instead:

dancing banana

We then inserted a 1″ (inside diameter) PVC pipe in the hole:

locker-build-van-conversion

And we applied Silicone II (Buy on Amazon) around the pipe inside and outside the van to ensure that no water can ingress in between the floor layers (do not use Silicone I on metal because it’s acidic and might promote rust, while Silicone II on the other hand is neutral and safe for metal)!

Propane locker build van conversion
Inside.
Propane-System-Installation-Camper-Van-Conversion-(20)
Outside.

Marine regulations ask for a minimum of ¾” (inside diameter) pipe to ensure a proper venting, so we will use that. The ¾” PVC pipe fit very tightly into the locker; we had to use a hammer to put it in place so it’s not moving from there.

Propane System Installation Camper Van Conversion (18)

Inside the locker, the ¾” PVC pipe protrude from above the surface (about ¼”) and Silicone was applied to ensure a proper sealing:

Propane-System-Installation-Camper-Van-Conversion-(Inside-PVC-Pipe)

Here is the oddly satisfying part: the ¾” PVC Pipe (fixed to the locker) fit nicely inside the 1″ PVC pipe (fixed to the floor), so the propane locker can be removed / re-installed as needed!

Propane-System-Installation-Camper-Van-Conversion-(pipes)

We added a ¾” PVC elbow to prevent crap from entering the locker. It is simply press-fitted into the ¾” PVC pipe:

Elbow
PVC Elbow

We’re not done with that box yet. We now have to add the bulkhead union fitting. As extra safety, the fitting should be installed near the TOP of the locker! Propane is heavier than air and will “sink” at the bottom…

propane locker bulkhead fitting

Oups… we installed the fitting towards the center and it’s in the way when we remove the tank! We relocated the bulkhead fitting towards the outside shortly after (not shown on the picture).

vented propane locker van build conversion

A rubber washer was installed outside & inside to ensure a good seal:

Propane-System-Installation-Camper-Van-Conversion-(16)

A self-adhesive neoprene seal (Buy on Amazon) was added on the cover to ensure sealing:

Vented-Propane-Locker-DIY-Cover

And finally, we added latches (Buy on Amazon) so the cover can be easily taken off:

Be aware that screwing parallel through the plywood’s layers is not ideal (the layers could separate under tension); but with the adjustable latches, we can fine-tune the tension to the minimum required. We also pre-drilled the screw holes to minimize the tension in the hole.

DIY-Propane-Locker-Campervan-Vented-Sealed

This is the assembly that’s inside the propane locker:

Camper-Van-Propane-System-Regulator-Solenoid (300px)
Propane Locker Regulator Solenoid Campervan

12.2- Solenoid Valve Installation

There are some propane and electrical work to do. It’s quite simple, let’s do it!

Solenoid Valve Installation Propane Van

Propane.

The solenoid is installed directly into the regulator outlet; we installed a 90° fitting so our assembly fits into the propane locker. (Don’t forget to use yellow tape on the threads!)

Camper-Van-Propane-System-Regulator-Solenoid (300px)
Propane Locker Regulator Solenoid Campervan

Electrical.

We went for a push-button that illuminate when ON; this way, we can’t forget to turn the propane OFF when we’re not using it:

Push-Button-Switch-On-OFF

We located the push-button switch at a visible place and where it’s easy to turn it ON:

propane solenoid switch location

This is how to wire the switch in a way that the LED illuminate only when it’s ON:

Solenoid Propane Switch Wiring

We wish we could find a nice bulkhead fitting to go through the 1/2″ plywood, but we couldn’t so we just routed the wire and added silicone to seal it…

Propane Solenoid Wiring Installation

We used quick-disconnects (Buy on Amazon) for when we need to refill the tank:

Solenoid-Propane-Quick-Disconnects

When the propane is OPEN, it draws 1.2A (solenoid and switch’s LED combined). For cooking or showering, the electrical power consumption is pretty negligible (around 1-2 Ah per day we’re guessing). When using the Propex heater, it’s a different story: if one would run the Propex all day, it would draw 29Ah daily (1.2A x 24h). That’s not negligible anymore, especially in winter when power is more scarce. In our case, we don’t use the Propex much as it is our backup plan (we prefer to use the gasoline Webasto).

propane solenoid and switch current consumption

13- On Second Thought...

  • Overall: The design we came up with works as intended, awesome!
  • Tank size: Our 20lb tank last 2 months on average (without using the Propex), that’s plenty! 
  • Regulator: We went through 2 Camco regulators and after some research, others are having the same issue. This thing doesn’t last more than a year… So we switched to the Marshall regulator and it’s all good now 🙂
  • That’s it for now.

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about us

Nice To Meet You.

Hello! We’re Isabelle and Antoine 🙂 In 2017 we sold our house (and everything in it), quit our engineering careers and moved into our self built campervan. We’ve been on the road since then and every day is an opportunity for a new adventure; we’re chasing our dreams and hopefully it inspires others to do the same!

117 thoughts on “Propane System Design Guide for DIY Van Conversion”

  1. I purchased the same solenoid. Does your solenoid get extremely warm/hot to the touch? I installed mine today and turned it on and within a minute it was really warm/hot. I’ve never done this before and just curious is this is normal. Thanks.

    Reply
  2. I’ve been using a camping stove instead of an atwood range or similar. If I want to add the optional hose to replace disposable 1lb tanks, how would I get the hose out of the gas locker? Is there a second bulkhead missing from the diagram for this?

    Reply
    • Because we used the high-pressure hose only for our showers (Mr. Heater aquacube at first, we then changed for the Eccotemp which is low-pressure), we just removed the locker cover when using it. Your situation is a bit different, I guess you need high-pressure at all time so removing the cover is not an option; I don’t know if there’s a bulkhead fitting that you can install… or maybe use copper tubing similar to the low-pressure?

      Reply
  3. I almost went with a propane tank mounted under my transit. (and may still have to). Reading your build of the propane locker with good venting and a well sealed box gave me pause to consider the same. The tank is definitely cheaper and the area where the undermount tank would have gone is still itching to have a grey water tank installed there instead. I am sold on its safety and it does make things a lot simpler. When you refill your tank do you have to remove it from the box each time? If so what do you think of those tank exchanges that stores like LOWES has? I am inclined to keep my own tank but was curious what you thought of those. ( Its quick, easy, and convenient but you keep getting a stranger’s tank…). Here is my special problem and I would value your opinion. I imagine you have to remove your tank for each refill. Although my garage is large enough to fit the propane locker, its not tall enough to lift out the tank. Where you have 40″ from floor to bed beam, I have 20″. My van is the medium high one. Obviously our bikes are not stored in the garage. Our garage height was determined by comfort in bed, ability to slip a kayak under the bed and what space we needed for battery bank, water tanks, ec. etc. So here is the dilemma. Instead of the propane locker having a removable top, mine would have to have a removable side. I would be able to slide the tank out for refilling. I would still have the adhesive neoprene seal, and four or six pull tight latches. So my question is: since propane is heavier than air, with your TOP being removable, were you confident with the neoprene seal because the propane would not build up there but would gather on the floor and out the vent? In my situation, (removable side piece) the neoprene seal would go down to the floor level. Is that seal good enough ? what do you think? My other options are back to the undermount propane tank, or fashioning a hatch cover under the mattress. Of course this means a not so convenient refilling situation (move bedding, mattress((we use a heavy futon)), hatch removal, all the disconnections etc etc.). So Antoine, Isabel, do have time to venture an opinion? Would love to hear it. Rich and Charlotte.

    Reply
    • Hi Richard,
      – Yes, we have to remove the tank each time (once every two month). We don’t mind it since is not frequent.
      – Exchanging a bottle is generally much more expensive than a refill but it would work.
      – I wouldn’t recommend a propane locker with a side-door, since it relies on a perfect seal. There’s a reason why all the marine propane locker have the door on top (propane is heavier than air and sink at the bottom)…

      Good luck!
      Antoine

      Reply
  4. Greetings! Thanks for the extensive write-up. I’m buying the propane diagram for sure?

    I’m heavily modifying a Sprinter based motorhome (2006 Itaska Navion 23J) for international travel. Since I’ve eliminated some propane hogs (refrigerator, generator & furnace), I want to remove the existing LP system and install a simple, 20# bottle and system like you did. This mod will save weight and greatly facilitate LP procurement, since my current ACME 1 3/4″ fill valve isn’t common abroad. I still have a water heater, cooktop and outside grill quick connect hookup. I also have an LP conversion dual fuel kit on my Honda 2000 gas generator, but won’t be using that much.

    Question: After being on the road 2 years, what would you do differently on propane design? Or, have you incorporated these thoughts into the diagram currently on the site? Thanks so much.

    John

    Reply
    • Hi John,
      The solenoid is something we added later on and, as you know, we incorporated it to our diagram. So yeah, the diagram is how we would build our propane system if we had to start over.

      The downside with our system is that the propane tank uses a considerable amount of space inside the van… there’s no perfect solution, it’s all about finding the best compromise 🙂

      Hope that helps,
      Antoine

      Reply
      • Thanks Antoine,

        Your comment does help. I’m a cold weather traveler. Locating the gas bottle/regulator inside the heated envelope is a benefit that partially offsets the downside of reduced storage. More and more and especially in South America, propane comes mixed with butane. Butane is no friend of cold temperatures, so I like the bottle and regulator inside.

        Thanks and good luck.

        John

        Reply
  5. Hi there! Just want to say thanks for all the awesome tutorials, I have learned so much from your posts! Quick question about the hose adapter. I am going to use a “bbq” propane tank for my camp stove and tankless water heater (similar to your water heater). Is it as simple as tank > hose > valve > water heater? Do I need a regulator? Thanks so much!

    Robyn

    Reply
    • You most likely need a regulator. Check the owner manual to find out what’s the pressure required for your water heater; if it’s 11WC, you need a regulator.
      So it should look like: tank > regulator > hose > valve > water heater.

      Good luck!

      Reply
  6. Wow. Awesome website and I visit it often. I’m currently working on my propane systems so, here I am tonight reading it for ideas. I also read some of the comments and wanted to share an article from the marine application regarding the solenoid placed inside the propane locker, https://www.westmarine.com/WestAdvisor/Safe-Propane-Installations. I hope this helps others too who have valid concerns of where to place the solenoid and the issue of an electrical item inside the propane locker. Thanks for sharing your amazing website and content.

    Reply
  7. Hey guys,

    I was wondering how you are liking your Atwood stovetop/oven combo. The amazon reviews are kind of spotty when it comes to build quality so I wanted to hear first hand. Also did you build a heat insulated box for it or no?

    Reply
  8. Hi. This may be a really stupid question but please could u explain to me the advantage of having the solenoid and regulator inside the box? If the propane vents from the tank itself and so can make that box a gas rich environment is adding a 12v appliance to that box not a potential igniter?

    Reply
    • A good quality solenoid + proper connections won’t spark. Putting the regulator inside the propane locker is mandatory per ABYC regulations (marine).

      Cheers!

      Reply
  9. I came across your site looking for reviews on the Propex HS2000 heater and was instantly intrigued being that your build components are exactly like what I am building (propane tank, air heater, water heater, stove, etc). That said I am debating on the Propex HS2000 or the higher output HS2800 and was wondering if your 2000 was your only source of forced air heat would it provide sufficient heat or would you step it up to the 2800? Also, if you were to build your propane system again would you consider an “underbody” tank setup instead or has your tank locker system proven to be a safe & convenient solution? Thanks for your time and your insightful efforts!

    Reply
  10. I am getting ready to install propane in my van and your website has been instrumental in my learning. I bought my products through your links–thanks. I have a question. It appears that you used copper tubing from your locker to the front of the van where your appliances are. Why would you not just use a long length of propane hose from the locker to the cabinet and split there? Seems much easier. Thanks in advance for your response.

    Reply
    • I’m pretty sure rubber hose is illegal inside a RV (as oppose to marine regulation); copper must be used per regulations. Because of vibrations, sharp edges and because critters like to chew on them.

      cheers!

      Reply
  11. Hi Antoine,

    As always thank you for the detailed write up. If it werent for your information im not sure I would be only a few days away from finishing our build!

    Have a question however. So we have opted to go with the echo temp hot water heater out back and a camp stove in the kitchen. So where I have my question is how to you properly get the 12ft “Throwaway Threaded Hose” out of the box? If you are using a bulkhead fitting to get the LP gas line out of the box for the water heater, is there a similar idea for the “Throwaway Threaded Hose”?

    Reply
    • Hi Peter,
      Our initial intention was to use the high-pressure hose occasionally only: during showers (Mr Heater BOSS), heater backup, outside cooking. Therefore we just removed the cover when we needed the hose. We didn’t have any bulkhead fitting for that, but you could probably install one.

      Good luck!

      Reply
  12. Hi Isabelle & Antoine, nice job on the web site. I am using so much of your info. The “High Pressure Hose” has a 1″ connector that is connected to the system inside the box while the hose itself is substantially smaller. I cannot see on any of your picture how you ran it through the 1/2″ plywood. You must have drilled a 1+” hole and then filled the slack in the hole with something. How did you do it?

    Reply
    • Our use of the high pressure hose was only occasional, so we didn’t drill any hole; when needed, we simply removed the cover of the propane locker.

      cheers!

      Reply
    • I have the same thought. I’m going to use the extra hose to connect to a heater, which means I’d be running it while we slept. I’m not sure what the best way to run the hose through the wall of the box is. I certainly don’t want to leave the lid off the box all night and I can’t find any sort of bulkhead union for fittings of that size. I hope that if the hole is close enough to the top of the box and I fill the extra space with silicone, the hose will be able to move back and forth and there will be enough of a seal to hold back any potential leaks.

      Reply
  13. I’m using this guide as my bible and I’ve got more questions. The two appliances I need to connect are a Mr. Heater Buddy and a fridge. Can I split the line coming from the tank, but before the regulator, and then install two bulkhead unions on the box? If so, would I need to keep the Mr. Heater connected at all times, or could I just install a valve on the outside (I don’t anticipate using the heater all that much).

    Thanks for the info!

    Reply
  14. This might be the dumbest of all comments, but how did you attach the propane box to the van? I don’t see any obvious anchors or straps. Also, is there any fear of sparks into the solenoid? Any point in putting that connection from the DC wire to the solenoid on the outside of that box?

    Reply
    • Hey, the tank is not attached since it fits tightly in the box; it’s not going anywhere 🙂
      Not worrying about sparks; it’s a typical installation in the marine world.

      And remember there is no dumb question!! Have a good one!

      Reply
      • I get that the propane tank fits snugly in the box, but I think the original question (at least, I have the same one) is: how is the box secured to the van?

        Also, how thick is the plywood you made the box out of? Do you have any more specs on the box itself?

        Reply
      • Anunta & previous commenter Simeon,

        I shared your hesitation to put an electrical component in a box that may contain flammable vapor; however, as Antoine mentioned it’s a typical installation in the marine world. Perhaps this will help put others at ease.

        https://www.westmarine.com/WestAdvisor/Safe-Propane-Installations
        “Propane Lockers
        All connections between the propane tank, regulator, and solenoid valve need to be made in a vapor-tight compartment separated from the interior of the boat, or outside of the boat in a location where leaking gas will not drain to the interior of the boat. If your boat does not have a built-in propane locker that vents directly overboard, we offer ready-made propane lockers. A vent line, as shown in the diagrams from the lowest point of the locker, must drain overboard above the waterline. The tanks must be well secured so that they cannot tip over and leak or become damaged.”

        Reply
  15. You have the wrong adapter in your optional 1lb tank replacement line. As described, you end up with the 1″-20 female end of the hose at your stove which also has a female fitting! Should be using [Mr. Heater 1″-20 Male Throwaway Cylinder thread x 1/4″ Female Pipe Thread Fitting] and this tee [1/4″ FPT x 1/4″ MPT x 1/4″ MPT].

    Overall this page was extremely useful. Thank you!

    Reply
  16. Hey Guys! Im in the middle of installing my propane and can not for the life of me figure out how a male flare interacts with a female flare when there is no copper tubing used. This comes into question with the 3/8 male flare T to the 3/8 female flare to 1/4 inch male flare? Does a brass flare to brass flare connection create a seal? You guys have been so helpful in this process. Thanks yet again!

    Reply
    • Flare connections don’t need anything for sealing; they are installed DRY as-it. That holds true as long as you use both male + female flare (flare to npt won’t be sealed). That’s the case for the adapter: https://amzn.to/2CSEVSE, since the female part (and male) are flared.

      Hope it makes more sense!! 🙂

      Reply
  17. I am building my propane system at the moment. I have bought 3/8 general purpose copper flexible copper tubing as well. It does not say on the tubing that it is rated for propane (just like the one in your amazon link). When reading online I have discovered there are different thicknesses (l,m,k) for copper tubing that make it appropriate for gas but the general purpose tubing we have does not seem to specify thickness. My question is, how do you know your tubing is safe for propane? Thanks.

    Reply
  18. Hello,

    Im installing an lpg tank myself, also with a sealed box. I have a question regarding your hole in the floor to let the gas leak outside in case of a gasleak. My question: is your tank sitting over/on top of the hole ? or made you the total box wider so total dimensions of the tank + some clearance for the width of the hole in the floor? my LPG tank has openings near the buttom but don’t know if that would be enough to let the gas leak out ?

    Many thanks and I hope you guys understand my question 🙂

    Reply
    • The sealed box is only .25″ more than the cylinder (on each side, so it’s pretty much the same size of the tank), but if you add your hole in one of the corner, the tank won’t be sitting on top of the hole.

      Hope that makes sense!

      Reply
  19. Great article, diagrams, lists, links, warnings, disclaimers and everything. It’s all useful!

    Question: I’m just about to install my propane system for a Propex heater, camping stove, and possibly an H2O heater like yours. I’ll be using it in the winter a lot for skiing and will be running the heat most of that time. So I very much appreciate your comment on power usage using the solenoid and probably won’t use one, but was wondering what might be the next best thing. Might a manual shut off valve inside the van, after the regulator, but before the manifold to the various appliances work almost as well? Just brainstorming here, and wondered if you might have some suggestions? Thanks!

    Reply

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