For the water system in the Sprinter, we had a few basic requirements:
For all our water tanks, I used ClassACustoms.com; they seemed to have the best selection and very reasonable prices. I wanted the water tank and all the lines to be within the insulated van, so it would be more usable in the winter. The drain lines and drain tanks are beneath the van, but we can add RV Antifreeze to those tanks and they should be functional below freezing. We ended up with a 33 gallon water tank within the van, mounted just over the rear tire on the right side. When full, this tank is around 275 pounds, not an insignificant number at all! Because the water tank is mounted reasonably high, the water fill had to be even higher. It ended up being just below the rear bunk window. This was an unfortunate consequence to the location of my water tank, but I still believe I would do it this same way again given the opportunity.
Leaving the tank, the water goes through a sediment filter, and into a SeaFlow 33 pump. The pump pushes 3.3 gallons per minute at 45 PSI, and is very quiet. After the pump, I added a SeaFlow accumulator tank to smooth out the water pressure, and then a large whole house water filter. After the filter, the water hose Tee's, with one line splitting into the cold water lines, and the other going into the water heater. Up to this point all of the water lines are 1/2" braided vinyl tubing. After the splits, I used 3/8" PEX tubing to run to the shower and sink. I wanted to use as small of lines as possible to the devices themselves, to conserve water, and allow hot water to arrive quicker. The 3/8" PEX still allows for plenty of pressue, yet holds about half as much water, resulting in hot water arriving in half the time.
I purchased a Foruee propane instant water heater for my setup. It is more or less an off-brand of the more common CampLux or Thermomate, but has great reviews, plenty of safe-guards built in, and had the spec's I was looking for. I wanted the smallest water heater I could buy, both to be more efficient (with water and propane) but also to be as safe as possible installed within the van. The unit is made to be used outside, so for now, we are opening the rear door when using it for any longer duration. I plan to install a permanent vent and fan for it in the rear door before winter (when it will get more use). I have installed a CO detector very near the unit just in case.
I do not think the propane instant water heater is the best option available, but I do think it's the best value, and worked out the best for us at this time. I love the IsoTemp Spa water heaters which have a tank, heat exchanger, and electric element. They're still not flawless but they use engine coolant to heat up the water tank, effectively giving you "free" hot water just by driving. The problem is your hot water supply is limited (unless plugged into a 120v outlet), and the unit costs about 5x more than a propane instant water heater.
I read quite a bit about different types of toilets, and ended up with the Thetford Porta Potti Curve. The unit looks and feels like a standard toilet, but is completely self contained and quick release.
...more to come...
I enjoy electrical work, so this phase of the build was something I was looking forward to. It did require some serious pre-planning, as well as some very hard decisions. I opted to use the space above the left rear wheel to house the electrical components. This cavity has room for 3 large batteries, a 2000w Inverter/Charger, a Smart Charger, and my fuse box and circuit breakers. It is also very near my switch panel, which is just above this cavity near the kitchen.
Most of my wiring was to be run through cabinetry, so I was lucky enough not to need to run too much before insulation and paneling.
1) 12V DC: Battery, charging, wiring, and devices
2) 120V AC: Powering, wiring, and devices
3) Solar Panels and Generators
12 Volt DC:
This is the standard electrical system in automobiles to power the lights, engine, etc. For my van build, I've added a second 12V system. This allows me to use the camper as much as I want, without ever risking draining the starting battery and stranding us.
Choosing a battery is one of the most difficult decisions I had to make. Lead-acid is cheap but extremely heavy, needs vented, requires maintenance and has a relatively short life span. Sealed lead (AGM) is more expensive, just as heavy, but requires less maintenance and doesn't need vented. They also last a little longer. Lithium is the future; it is far less weight, more versatile, longer lasting, and more powerful.
I had chosen the mid-range AGM battery, but while shopping brands, I was convinced to splurge on Lithium. The single Ohmmu 150AH Lithium battery I landed on has the same useable power as three 100AH AGM batteries and weighs around 30 pounds, while AGM would be well over 150 pounds. The Lithium should also last twice as long, and allows for faster charging and discharging.
For my 'phase 1' charging system, I installed a Renogy DCC50S DC-DC Smart Charger with MPPT. This unit is the interconnect between the engine (and engine battery) and my camper lithium battery. When I start the van, the charger waits approximately 15 seconds for the alternator to recharge the starter battery, and then begins to allow the alternator to charge the camper battery as well. The smart charger adjust voltage and amperage to optimize the charging for the specific type of battery, which helps with charging and battery life span. The unit pulls up to 50 amps from the alternator, but reduces the pull as the battery gets closer to full. With a built in MPPT charger, the unit also has inputs for solar panels, which it uses to charge the camper battery as well. The unit will also use the solar panels to trickle charge the starter battery if the voltage begins to drop due to not being driven. Solar panels will likely be my electrical system phase 2. For now, this smart charger is the only method I have installed to charge my battery. Our intention with the van is to drive it every day we're using it, either to travel, or even simply to hiking trail heads or lakes. With that in mind, the smart charger is ideal. If we were planning to park and live in the van without driving every day, we would need to add another charging system (Either solar or 120v AC). In testing, one afternoon and night of living in the camper uses between 10% and 15% of our battery, which is then completely recharged in under 1 hour of drive time.
Wiring for 12 volt DC gets a little tricky, and I used THIS wire gauge calculator quite a bit. Lower voltage power requires higher amperage to accomplish the same task, as higher amperage draw requires thicker wire! Not something you normally think about in automotive setups, but once you begin to think about charging batteries or power inverters, amperage draw becomes a real concern. I bought a large spool of 14 gauge In-Wall Speaker Wire for the majority of my low voltage devices. This wire is wrapped in a white sheath, providing a very clean look, as well as an extra layer of protection against rubbing through. My main charging power is run through a 4 gauge wire. When the engine is charging at the full 50 amps, this wire gets warm.This isn't necessarily an issue, but it is a sign of wasting power. In hind sight, I wish I has run 2 or 0 gauge wire for this span. My charger and battery are near the back of the van, so no question the distance (around 22 feet of wire) is playing a role in the inefficiency. I did run 0 gauge ground wire to future proof the setup, planning ahead for when I add additional charging systems.
Almost all the devices I've added in the camper are 12 volt DC. Our intention is to be able to live off the battery, without requiring an inverter, generator, or plugging in. With that in mind, there are only two devices I've installed that will currently only work if we plug in; the rooftop AC/Heater, and the Microwave. Everything else runs off the battery including the lights, MaxxAir roof fan, USB ports, and the water pump/heater.
120 Volt AC:
This is standard household power, and I've added a plug to the back bumper so I can use an extension cord and plug the van into a normal power outlet whenever I'd like. By plugging the van in, we can run the rooftop AC/Heater and microwave. The refrigerator I bought, while is extremely efficient running off the battery, will also automatically switch to household power if it senses 120V becoming available. In phase 3 of my elecrical system, I'll be adding an Inverter/Charger, which will also charge my lithium battery whenever I plug the van in to a household outlet.
I opted for 10 gauge wiring for the main power feed. This is overkill, but I had it leftover from a previous project, and don't ever want to have to redo this wiring. I ran 10-3 wire through a water-tight conduit from the back bumper 'power inlet' up to a 20 amp GFCI outlet in the kitchen area. From the protected outlet, the 10-3 wire continues up to the rooftop AC/Heater, while more standard 14 gauge wire continues to the microwave and refrigerator. I had originally considered extra outlets inside and outside the van, but eventually decided that we simply don't plan to use many 120 volt devices.
I did purchase an extremely heavy duty 10 gauge extension cord to always keep in the van. Again, this is most likely overkill, but as I had to buy a cord for the van, I wanted to buy the best I could. The cord powers the AC perfectly.
Solar Panels and Generators:
Phase 2 of the electrical system will be adding solar panels. The Renogy charger I have installed can handle up to 600 watts of solar panels, and my roof has enough square footage to fit about 550 watts. It would be far easier, and a bit less expensive to go down to 450 watts, and I'm leaning that direction. With our lights on full, the refrigerator running, and our fan on max power, we're still using less than half that amount of power. Ignoring the rooftop AC and microwave, 450 watts of solar would power us indefinitely, even considering the inefficiencies of peak times of day or shade. I plan to install 3 HQST brand 150w solar panels, with 10 gauge wiring from the roof down to the Renogy charger.
As far as a generator is concerned, the only purpose would be to run the AC or Microwave, neither of which we are considering a necessity. Our goal is to not need a generator, and we do not plan to carry one with us for most trips. That being said, I have tested a Honda EU2000i generator, and it powered our rooftop AC without issue. On the occasional trip where we know it will not cool off at night, we may bring one along just to be able to run the AC for a bit before bed. If we know we will need to run the AC all night, we will likely choose to stay at a campground with a power outlet. If I were to purchase a generator, I would look for a used Honda EU2000i, or purchase a new Predator 2000.
Pictures to come!
Prepping the shell was obviously step one. We decided on three windows, two small behind the driver and passenger seat, and one a little larger in the back next to the bed. All three came from VanWindowsDirect.com, and slide open with screens. Quality is fine, but nothing awe inspiring. I found a jigsaw with a metal blade was by far the best option for cutting the holes. We then primed all the cut metal with rust preventing paint, and installed the window with white Quad Max sealant.
On the roof, we decided on one MaxxAir fan towards the front, and the rooftop AC with heating element towards the rear. The Maxxair fans are extremely nice because they can remain open in the rain. They also can take air in or blow air out, and have 10 speeds, ranging from extremely low power and silent, up to 800CFM. We placed the fan towards the front so it sits between the kitchen and bathroom, and can act as an exhaust fan for both.
For the rooftop AC, I chose the smallest unit I could find. The Coleman Mach-8 Cub pushes around 9000 BTU of cooling at about 1250 watts of power, or 6000 BTU of heating at 1750 watts. We can run this unit off a standard 15 amp household outlet, or a small generator. In theory, a few batteries and 2000w inverter would also power this unit, but I do not know if I'll be buying an extra battery simply to run the AC. I plan to add an additional furnace for regular use, but for the minimal cost of adding the heating element, I felt it was an easy choice to add it for times we are plugged into shore power.
While the MaxxAir fan works exactly as we had hoped, the rooftop AC unit is quite a bit louder than I'd like, and the heating element seems to not be working. We will sort the heating element I'm sure, but it's difficult to test in the heat of summer. The noise is simply the larger blower fan right above our heads. The unit actually seems quieter outside than inside. Luckily the noise stays consistent, rather than older AC units which would abruptly turn on and off to control temperature.
Finally, insulation! Their are endless debates about the best options, but I used my own past experiences to know exactly what I wanted to use. Mineral Wool insulation is moisture, mold, and mildew resistant, as well as fire resistant to over 2000 degrees. It's also readily available, reasonably affordable, and a little more efficient than regular fiberglass insulation. It's not particularly healthy, but all of ours will be encapsulated so I went with it. I filled as many cavities and spaces as I possibly could with the mineral wool, then I went through with expanding foam insulation to fill all the smaller cavities. I use the "window and door" type so it can't expand too much and flex the metal. After that, I wrapped the entire sides with an automotive "Sound Deadener and Heat Barrier Mat". This 1/4" thick foil faced foam provides extra insulation, a solid moisture barrier, and a cushion so I can screw my paneling to the metal of the van, and not worry about any squeaking.
I insulated the ceiling with 1" thick rigid foam board, again sealed with a layer of the "Sound Deadener and Heat Barrier Mat". The flooring was a little more challenging. I wanted the absolute miminum thickness, while still being an effective insulator. I ended up cutting strips of the 1/4" insulating mat to fill the gaps between the 'ribs' in the flooring, then laying a piece of 1/2" rigid foam board over it. The flooring we used also has a cork backing, which has a little additional insulating value.
Roughly speaking, our floor is insulated to around R-6, our ceiling is around R-9, and our walls are around R-12.