As calculated above I need something between 6000 and 10.000 Watts as maximum heat capacity.
If I take the smallest 6.000 I will have difficulties to warm the RV up in case of cold starts.
But if I do not let cool down the interior in these extreme situation at -40°C up to -50°C then I can do it with only 6.000 Watt.
When I take the 10.000 Watt versions I will not use this maximal power for more than 95% of the heating and travelling time.
Remember that in overnight situations in tempered climate zones I will only need 500 Watt heat capacity.
You understand that a heater of 10.000 Watt can than become a problematic solution.
It runs constantly too cold on idle and wil commute between its off and low positions and never reach its good warm functioning level.
The too cold combustion for very long periods can cause soot formation. .
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The 3 main reasons to decide for 2 heaters instead of 1 are;
- Larger heat range possible between minimum and maximum power stages.
- The best of two worlds (take the advantages of an air heater AND the advantages of a water heater.)
- Have some redundancy. It is important accessory .Without heater your trip is over.
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The AirtronicD2 warm air heater is certainly one of the best products that was ever made by Eberspächer of Esslingen Germany.
It is very reliable and relatively easy to install.
At the first start it goes quickly up a sort of turbo heating level (2.200 Watt) but once that the ambient is on living temperature it
commutes deeper down until a sort of idling modus (850 Watt) is reached where you can almost not hear it any more.
This makes it the most comfortable heater for overnight sleeping in silence.
I will put only one central warm air outlet in the middle of the compact interior to avoid long lines and losses.
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Why is there a need to also have a Hydronic D5 warm coolant heater ?
Because I need a warm water heater for the calorifier and the 2 grey and black water exterior tanks.
The coolant loop inside these calorifier (boiler) will take up like maximum 1500 to 2000 Watt when the sanitary 20 to 40 litres are cold like +5°C.
This for only a short period until the boiler is warm.
The Hydronic D5 water heater will also have to regulate.
It has as maximum power 4.800 Watt medium is 2.100 Watt and the most important is small with 1.200 Watt.
Remember why small is beautiful.
The heaters will run for extreme long periods on the lowest power level and only shorter periods in medium and high.
If the lowest power level is like 2.500 Watt it will continuously commute between off and on what is not funny at all.
That is why a Eberspächer Hydronic D5 is for me the best.
The water system will be complex to install with different heat exchangers all over and including a special electrical 3 way valve regulation
on the exterior tank heating loops.
Also 3 different temperature controllers and ventilation speed regulation will be installed on this system like for the garage and bathroom.
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These Eberspächer (called Espar in North America) gasoil (=diesel) heaters function down to -40°C according the technical descriptions.
For some military applications they are released down to -46°C. For deeper temperatures, if you can find them somewhere on the
planet, there will be no warranty anymore :wings:
Most vehicles for that low temperatures are build for only Artic use and are not comfortable at all.
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The alternative product would be to take the Webasto Airtop 2000ST (2000 – 900 Watt) + Thermotop Pro 50 eco (5000-2.500 Watt) water heater.
The main disadvantages of the Webasto’s are that the heat and regulation range of both these comparable heaters is less wide than with the Eberspächer chose specially on the low heat side.
The other disadvantage is that the Webasto combustion principle is one that needs maintenance.
Other features for the expedition vehicle are for me less relevant in my comparison.
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Regards Campo
