A studio apartment on wheels
This is a very comfortable tiny house. Rent a driveway or part of a backyard and be fully self contained in your own place! Or hit the road for an extended camping trip.
Length 11.7 m
Weight 11990 kg (MR license required)
Seats 6, sleeps 3 (full queen sized bed, plus sofa / single bed)
Reverse cycle 2kW Daikin air conditioner
5kW diesel heater
Double glazed windows
200L water tank
250L grey water
7 kWh lithium iron phosphate (LFP) house battery (24V, 272Ah)
550W solar panels, victron MPPT solar charge controller
3000W tortech pure sine wave inverter
250W victron pure sine wave inverter (for the fridge)
LG fridge
Alcohol fuelled cooktop
Nature's Head composting toilet
New wheels and tyres (as of about 2 years / few '000 kilometers ago)
Nerdy details
When I bought the vehicle in 2016 it had been converted to a motorhome already but was more or less an empty shell. The design philosophy I followed in fitting it out was simplicity and frugality - allowing for extended periods "off grid" away from power, water and waste facilities.
The electrical system
The electrical system is standalone / solar only - it doesn't connect to the electrical grid. Power comes from three 24V, 185W solar panels mounted on the roof. These are wired in parallel to minimise power loss from partial shading and stay within the voltage limit for the solar charge controller.
The panels are hinged and have gas struts so that they can be angled towards the sun in winter (if you're facing east!)
The charge controller is a Victron 100/30 MPPT unit with bluetooth dongle so you can check what it's doing from your smart phone.
The charge controller charges the house battery, which is a custom built 7 kWh lithium ion battery using LiFePO4 cells (the safe type) and a 150A Daly smart BMS. This has a bluetooth connection too, so you can check all the cell voltages / battery temperature etc. from your phone. The battery has a 200A fuse and is mounted in an insulated box with a ventilation fan controlled by a temperature controller. If the enclosure temperature goes over setpoint, the fan starts and draws cool air from under the bus. This all keeps the battery pack pretty close to an optimal temperature range at all times of the year.
The house battery and all vehicle DC systems are 24V.
The house battery is connected to a fuse box / DC distribution wiring which powers lights, water pump, ventilation fans and the smaller inverter (which powers the fridge). There is also a double fused (one at each end) interconnector between the house battery and the vehicle battery with a switch and a diode. When the switch is off, the two batteries are isolated. When the switch is on, the house battery keeps the vehicle battery fully charged but the diode means that power can't come back the other way. This stops the house systems from flattening the vehicle battery. The charge controller and BMS are tuned so that everything works properly, with "fully charged" on the lithium house battery being pretty much the ideal float voltage for the lead-acid vehicle batteries. The house battery is programmed to stop charging at 3.45 V per cell (a bit below the recommended maximum of 3.65 V in order to maximise battery lifetime).
The house battery is also directly connected to the larger tortech 3000W inverter (internally fused) which powers the 240V system for the house. The 240V from the inverter goes to an earth leakage safety switch and then to the 240V wiring which has a pair of outlets under the table, another pair by the kitchen bench, and a third pair at the rear of the vehicle. I only ever switch on the inverter if I want run the vacuum cleaner or the toaster, the air conditioner or electric blankets :-)
The solar system can harvest 3 kWh per day on a good sunny day and for perspective the fridge uses about 0.5 kWh per day.
The water system
A 200L fresh water tank, mounted underneath. Fill from a garden hose via the filler cap. The water pump is a 24V pump that operates off a pressure switch. It has its own isolation switch and fuse.
When the pump switch is on, the pump starts if you open the tap.
The pump feeds water to a standard domestic under sink water filter, to the single tap at the kitchen sink. This is the only water outlet on board, to discourage profligate water use. You can have a hot shower, but you'll need to heat water in a kettle, pour it into the camp shower bag, and hang that in the bathroom. Short showers! Saves water!
The kitchen sink and the shower pan both drain to the 250L grey water tank, mounted underneath.
Toilet
One of the best features is the composting toilet - no messy black water tank! No need to find a dump point!
Urine is diverted at a tank at the front of the toilet, which you carry out and can empty into any caravan park or public toilet. Everything else goes to a soil box at the rear, where it's mixed with coconut coir or sawdust. You only need to change this out after a few weeks of full time use, at which time you can just bag it and drop it in a rubbish bin, or you can age it and use it as a soil ammendment. I had some of this stuff in a closed bucket for a year and it had literally turned into soil. Even the toilet paper was completely broken down.
The toilet has a tiny 12V fan that keeps it under negative pressure, exhausting the very slight odour to the underneath of the bus. You can only smell it if you go underneath and go right up to the exhaust. It has a slight musty smell, like soil or wet leaves. It's completely odourless on the inside of the bus.
Cooking
LPG is not fitted. There's an Origo 2000 alcohol burning stove top, mainly for compliance. I usually use a portable butane cooktop, plus an electric toaster. I have used an electric slow cooker without issue, and a microwave oven would work (not installed).
The fridge is an LG 194L one-door fridge (internal freezer compartment). I picked this one because it fits in the custom made kitchen cabinet and has one of the lowest energy consumptions.
Ventilation
A small 12V fan runs all the time, sucking air from the bathroom and exhausting it under the bus. This actually turned out to be a genius idea because you can hang wet towels or clothes in the bathroom and they won't make the bus interior humid. Dry air from the living space goes into the bathroom where it dries things out and then goes out of the bus.
A FanTastic vent fan (also 12V) is mounted in the roof where the rear roof hatch of the bus used to be. This is used to suck hot air out of the bus. It has a rain detector that closes the lid and keeps the rain out if it gets wet (dew will also do this).
Apart from the sliding bus windows, the front bus roof hatch is hinged and opens with a gas strut to provide extra ventilation and access to the roof for cleaning solar panels or tipping them up or down to catch the sun.
Heating and cooling
2kW Daikin reverse cycle air conditioner in the rear bedroom area helps keep things cool, works most effectively if you hang a blanket to cool just the bedroom.
5kW diesel heater keeps things toasty in winter. This sips diesel from the fuel tank at a tiny rate, heating the air inside the bus. No smell - all the combustion gases stay outside.
The windows are double glazed with transparent polycarbonate sheet, which helps keep things cool / warm and also stops condensation forming inside the windows. The windows are coated on the outside with perforated film (like many commercial buses) so you can see out but can't see in during the day. It also helps minimise solar load coming in through the windows.
Lighting
LED strip lights throughout, LED downlights for the front door. Separately switchable lighting for the dining area, kitchen, bathroom and rear bedroom.
On the road
This is not a fast vehicle. 0-100 km/h in a couple of minutes :-)
It's very comfortable to drive on the open road, like driving an armchair at about 90-95 km/h. It'll wind out to 120 on a flat straight road if you really want to push things, but I don't recommend that - it uses about 50% more fuel than it does at 90. No turbocharger, so it is slow up hills.
Speaking of fuel (diesel), about 25L / 100km on the highway, a bit lower than that if you keep the speed down to 80.
It's a naturally aspirated PE6 engine - 12L, 6 cylinders. Rear mounted. It was resleeved before I bought it, have had no trouble. 5 speed manual transmission, with synchromesh. Just the same as driving a car - only bigger and slower.
It has an exhaust brake, like a truck and unlike most buses.
That's it!
I think that's all? If you have any questions please ask them by leaving a comment and I'll reply or edit the text to make it clear.
