Diesel heater for your caravan.

[condor22]

Remembered I posted a thread back in 2015 re heater install. The first 20 posts were re an install of a Planar (knockoff) Heater I bought to put in my current van. However as I won some cash, I sold it and got the Dometic I now run.

There's some info on what I was going to do with the Planar re install, similar heater, different fuel tank and the rest of the thread is on the actual install of the Dometic.

Might give some ideas for others when installing a heater. Here's the link

https://www.prospectingaustralia.com/forum/viewtopic.php?id=11793

 

[Nightjar]

Thank you all for the information to get me and hopefully others on the right track, heater installation will be happening through the warmer months in readiness for 2022.
Special thanks to Tathradj for explaining the ideal fuel tank set up, ours also be fitted in the front boot. As we all know one drip of diesel in your air space is not pleasant.
That is number #1 concern out of the way.
My second concern was diesel exhaust fumes and now that has been put to bed. The cool air inlet and the warm air discharge all happens within the confines of the van interior, not forgetting air vents into heater position.
Thanks Doug, had blinkers on, all of the models I looked at had the intake and exhaust poking outdoors and was a little confused.
The penny dropped and realised this was for combustion only, the clean air is circulating around the units separate heating chamber.

 

[Nightjar]

While trolling around have just found a recommendation to upgrade the supplied wiring to the unit if there is a likelihood of any voltage drop from battery to unit.

Who can give a vote for the most reliable unit they have purchased in 2021?

 

[Jaros]

The reason is that distance is resistance in smaller gauge wiring that's where the problem is. Try and keep it as short as possible-if not use some thicker stranded wire.

 

[condor22]

NJ - Here's some links to calculators/conversion

Voltage Drop
https://www.rapidtables.com/calc/wire/voltage-drop-calculator.html

AWG to mm sq
https://www.multicable.com/resources/reference-data/cross-reference-awg-to-mm2/

Using 10 amps as the load (temporary) 10 or 12 AWG will be fine in most scenarios so calculate the drop for both. Keep in mind that voltage drop in a DC battery system is 2 fold.

1. The wire gauge will have a drop due to wire resistance over length, with a constant voltage source i.e. power supply. An AGM deep cycle battery is not a constant source, (next point).

2. Be aware you will see a bigger drop on battery volts depending on battery type, size and condition. My AGM dropped around 0.5 volts when the Glo Pin was on, then when the load dropped as it turned off the fan 1-2 amps only caused a 0.1/0.2 drop and the battery volts recovered. (Battery full and in good condition.) The more combined load, i.e. TV, lights and heater etc, the more an AGM voltage will drop. Lithium does drop, but not as much as an AGM, only around 0.2 volts at 10 amps, now I have a LiFePo4.

 

[Tathradj]

10 or 12ag is more than ample for a 1 to 2 meter run.
I am sure the safety cut of voltage is 10.9 volts.

Oh, Wire it directly to your battary(s) as they need
to have a cool down cycle.
Use the supplied fuse.
If you a have an isolation switch, You could accidentally
switch it off half way through a cool down.

Also no voltage drop either.

In a Caravan, Earth to Battery earth. Best to keep your 12v
circuits floating. Not to use the chassis.
Could get tangled up with the 240 system plus, Not cause any
feed back issues with a computerized tug.

The end result could be a bit of a disaster. Handy for thieves though. :bomb:

 

[Tathradj]

About the last few tips I picked up in research and practice.

Don't extend the exhaust pipe longer than 1. 5 meters.
Other wise, Your heater will choke up.
symptom of this is lots of white smoke on startup then not running.
Solution is if it gets that bad, Pull it out and service it.

The fuel pump,
Take close note about the angle it has to be mounted on.
Then,
In the middle of the night,
Thunk,,,Thunk,,,Thunk,,,Thunk,,, ]

Worse than a dripping tap. ]
Thunk,,,Thunk,,,Thunk,,,Thunk,,,

I have not done it yet but there is a silent run fuel pump.
Going to get one then toss the original in a drawer
some where to roll around until it may not be used.

Did I mention,
Thunk,,,Thunk,,,Thunk,,,Thunk,,, :skull: :skull: :skull:
Oh this is only when the heater is running.

 

[Tathradj]

This is the same as mine,
https://www.ebay.com.au/itm/2230589...7p1dvQRGl3dl%2BcPzwI|ampid:PL_CLK|clp:2334524

Must also point out,
Go get some better quality hose clamps for the inlet/outlet and fuel hose.

They not to good.

 

[Nightjar]

Will definitely not be running it once we a tucked up in bed. So no problems with " thunk, thunk, thunk."

 

[Nightjar]

Have been looking at several deals including what Doug posted. (negative feedback on several of the models)
https://www.ebay.com.au/itm/223058984391

Another question for those who have a heater installed;
The diagrams show different pumps on an angle, some have the suction lowest others highest, which is correct?

 

[Tathradj]

Suction lowest,
Discharge Highest.
There is generally an arrow stamped on the pump.
I bench tested my heater for a few days before installing it.
They can run on one side but it must be the glowplug side up.
There is a small metering hole near the glowplug.

The pump creates cavitation. This allows
for the air bubbles to be dispersed from the fuel.

 

[Nightjar]

Many thanks Doug, suction lower makes sense.
Lifted off the padded seats around table in the van today and there is an ideal spot in vacant area above/between the twin axles. Will be able to direct heated air in two directions, will check of course before pulling out the hole saw and drilling a hole in the floor.
Will also do what you did and bench test it before final installation.

 

[Tathradj]

Great to see another thinker. :Y: :Y:
That is the main reason why I placed mine where it is.
Fair square between the axles and under the main seatee.

1996 Chatue, Ex "Viscount" Van.

 

[condor22]

Another tip for you NJ, get a stud finder. i.e. do some serious measuring of the under floor steelwork of any area you install. Last thing you want is to start drilling timber and hit RHS.

 

[Tathradj]

LOL,
True,
I sighted mine very carefully then,
drilled a tiny hole finally sticking a piece of wire down through it.
got it right first time.
Within 2 inch's.

 

[Simmo]

Wallabot!

 

[Nightjar]

Picked up this one for $99.99, should be here later in the month.
Just hope it is not a lemon.

https://www.ebay.com.au/itm/384352736100

 

[shakergt]

Nightjar I have had a portable ebay for a month now and very impressed with it. I managed to heat my 6 x 8 m shed with it.

 

[Nightjar]

Heater is here.
Another question:
The 10L fuel tank has two pads for installing suction pipe, one on the side and one on the bottom.
Any tips for installing the aluminium suction fitting?
First thoughts is a length of wire fed through a holed drilled in the tank up and out the filler cap spout through the fitting and secured then pull it back into tank and hopefully able to align it and pull it through hole?
Any help would be appreciated.

 

[Tathradj]

What you said is the way it is done.