NPS Camper Build

[LeishaShannon]

The floor to wall intersection is the same as the other edges, the floor has the rebate cut out of it (red in the diagram). Accurately placing the ~100KG floor (the floor has twice the glass thickness as the walls, its much heavier) inside the aluminium frame with the 3mm gap all the way around was interesting. We placed a couple of curtain rails from bunnings across the frame, lifted the floor onto the rails, then rolled the rails toward the rear of the truck which allowed us to accurately position the front edge of the floor into the frame.

 

[prontozuk]

Hi,

i have been researching and lurking for years and i have a question. Where did you get you Vanglass panels from and CNC cut as well.

Thanks James

 

[LeishaShannon]

We got them directly from Shaun @ Vanglass http://vanglass.homestead.com , they're practically around the corner from Peregian

 

[whatcharterboat]

Hi,

i have been researching and lurking for years and i have a question. Where did you get you Vanglass panels from and CNC cut as well.

Thanks James

Yeah, 15 minutes drive from Peregian . They're directly opposite the Ginger Factory in Yandina. Regards John.

 

[gait]

just round the corner from ATW .....

John, your PM inbox is full ......

 

[whatcharterboat]

just round the corner from ATW .....

John, your PM inbox is full ......

Hi Julian,

Sorry. had a clean out a couple of days ago. Should be right now.

Regards john

 

[ianc]

Progress report with pics? Please....

 

[LeishaShannon]

Progress has slowed again, damm work keeps getting in the way!

The electrical system installation is underway at the moment. It consists of :

360Ah @ 24v LYP Batteries
1500W of Solar (1200W of LG MonoX Neon on the roof , 300W "portable" for when we're parked in the shade)
150v / 70A Victron BlueSolar MPPT Controller (Backup controller still required, we're waiting for Victron's new 150/35)
2 x 1600VA Victron Multiplus Inverter/Chargers configured in parallel for redundancy
2 x 25A 24v to 12v DCDC converters in parallel for 12v loads configured in parallel for redundancy
Victron BMV-702 and Colour Control GX for monitoring and control of the entire power system



We're planning to have no gas/diesel appliances and doing everything using 240v appliances. So far we've got:

Samsung 255L inverter refrigerator (measured 23watts average load over a week)
2 x Single plate induction cooktops
Sheffield Convection Microwave Oven + Breadmaker + Grill Combo (We've been using this in our house for the past year and love it)
Mitsubishi Heavy Industries 2kw reverse cycle inverter AC (This unit is the most efficient we could find, draws a maximum of 350W and a 180W minimum)
24L Force10 Marine HWS (240v + hydronic, but we're not hooking up the hydronic side initially)

 

[gait]

nice to see it coming together,

good find on the aircon

 

[ianc]

Mitsubishi Heavy Industries 2kw reverse cycle inverter AC (This unit is the most efficient we could find, draws a maximum of 350W and a 180W minimum)

Dumb Question time! - How can an AirCon unit deliver 2Kw of cooling with just 350w of power?

I

 

[LeishaShannon]

Not dumb, I spent some time looking into it and still don't quite understand But I believe the air conditioners are marketed based on cooling (or heating ) capacity rather than the electrical consumption. When heating they're pumping heat from outside to inside. A simple bar/element heater requires ~1 kw of electrical power to generate 1 kw of heat but an AC is able to pump that same 1kw of heat into the camper using less electrical energy. The COP (Coefficient of Performance) is defined as the power output / power input and is a simple measure of how efficient a particular unit is. The COP for the Mitsu is ~5.7 , there is a Daikin model thats just over 6 but unfortunately its a much bigger and heavier unit which wasn't suitable for us.

 

[gait]

Dumb Question time! - How can an AirCon unit deliver 2Kw of cooling with just 350w of power?

I

air conditioners, fridges and a few other appliances are "heat pumps". The input power is used to drive a coolant circuit that transfers heat energy from a hot side to a cold side.

The Carnot Cycle is a well known mathematical representation of the circuit. Efficiency depends on temperatures of hot and cold sides.

The coefficient of performance is energy out divided by energy in. COP for this appliance is 5.7 (2000/350) which is high and approaching the theoretical maximum (from Carnot Cycle).

The Samsung fridge also looks like a good find. COP of fridges is typically lower than air con as temperature difference between hot and cold sides is higher.

Inverters in the context of air con and fridge have a subtly different meaning to inverters that give 110/240v AC from 12/24v DC. They are used to match appliance operation to demand, which can be much more efficient than on/off control, and much more pleasant.

The whole electrical setup that LeishaShannon have chosen looks like the way of the future to me. Nice to see good research. My AGM batteries died somewhere in Tibet and I'm looking for an upgrade so follow with interest.

 

[Flys Lo]

That is pretty much it. Cooling and heating capacity is determined by how much energy can be either injected (heating) or removed (cooling) by the air conditioner. With an air conditioner, this energy is just transferred to an external surface thru compressing/expanding a fluid that is driven by a pump. The 350W in this case is the power that is required to drive that pump, and the electricity required to operate the system.

This is the same as your refrigerator/freezer/home air-conditioner. It may have a heating/cooling capacity of 6500W/6000W respectively, but it may only take 1500 W of electricity to drive the pump.
This is also why they are much more efficient than radiators (for example).


On edit: got beaten to it.

 

[whatcharterboat]

Dumb Question time! - How can an AirCon unit deliver 2Kw of cooling with just 350w of power?

I

Hi Shannon,

I've fitted a few split system / inverter type AC units...... just a word of advice, pull the cover off the condenser unit and check all the bracketry and how secure all the cables are. It should be obvious where you can beef things up and provide extra support. These units were not made to do corrugations on Cape York. Also some units are available with a stainless case. From memory, you were going to fit yours up high on the front panel of the body....this should prevent a lot of dust ingress normally associated with mounting on the rear bar as many are.

Regards
John.

 

[azzad]

Inverters in the context of air con and fridge have a subtly different meaning to inverters that give 110/240v AC from 12/24v DC. They are used to match appliance operation to demand, which can be much more efficient than on/off control, and much more pleasant.

The difference being that they actually convert the 110/240v AC to DC so they can vary the speed of a DC compressor efficiently. My father in law and myself were toying with the idea of working out how to run 1 direct from DC therefore bypassing the voltage conversion and making it more efficient.

Dazza