What is the BEST....High Altitude Solution for Heating?

nick disjunkt

Adventurer
We just spent a couple of days at 10,000 feet at the campsite on the side of La Malinche volcano and neither the altitude equipped Eberspacher D2 or the unmodified Webasto Thermo Top 50 had any problems
 

LoRoad

Adventurer
We just spent a couple of days at 10,000 feet at the campsite on the side of La Malinche volcano and neither the altitude equipped Eberspacher D2 or the unmodified Webasto Thermo Top 50 had any problems

Thanks for updating us all with this information Nick!
 

nick disjunkt

Adventurer
Please tell me if my updates are getting boring and I'll stop.

Last week we spent a night at 12,200 feet on the Nevada de Toluca volcano. We drove to 13,650 feet but slept a little lower as the quick ascent had given me a headache.

The standard Webasto Thermo 50 worked fine for the hour that I ran it to heat our water tank. I didn't check the exhaust for smoke but it started first time and cycled normally.

The altitude equipped Eberspacher D2 worked fine for the four hours that I ran it, but it only started on the third attempt. On the first two tries, it shut down and restarted the warm-up cycle.

I'm not sure if it was the temperature (well bellow freezing) or the altitude, but the truck engine spluttered a little on startup. It started first turn as it always has, but it coughed a little and hesitated longer than normal. The truck didn't smoke at all, and power only seemed marginally down on normal.
 

LoRoad

Adventurer
Please tell me if my updates are getting boring and I'll stop.

I'm pretty sure the group will back me on this: DO NOT STOP :) Everyone loves hearing about the adventure and how specific equipment is working in the 'real' world. Thank you for taking the time to post this information for all our benefit.
 

biotect

Designer
.
There is an interesting exchange between charlie aarons and egn in the "MAN 6x6 camper" thread, that addresses roughly the same topic as this thread – see http://www.expeditionportal.com/forum/threads/11614-MAN-6x6-camper/page6 , posts 53 and 55:


Are diesel stoves like Wallas or Webasto as bad at altitude as rumored? Webasto's current offering has a "high" altitude setting but supposedly it's set for 2000m. The Tibetan plateau is 4-5000 m., Altiplano 3500-4000. Can a diesel stove be successfully used at these altitudes? My intuition says no.

Charlie

Sorry, I misunderstood this first and thought you mean the diesel furnace. I leave the text below, because this is also an issue at high altitudes.

I agree with you regarding the stoves.


Diesel furnace:
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I know from people that where at about 3,100 m that they had no problem with the standard Webasto. You can also install a second diesel pump with a second control unit which uses a reduced amount of diesel corresponding to the available oxygen. I haven't looked into this in detail yet, because there are a few years until we will be at this height.

I personally have also thought about a more general solution for being at such a height. I don't know if it works, but in my opinion it can. I want to install a blower to increase the air pressure in the cabin. The cabin is very air tight if every opening is closed. So at night the comfort may be better.

This can be also used to increase the air pressure at the air inlet of the Webasto. This is something like a turbo. This was one of the reasons why I took the 6x6. This Deutz engine has a turbo and the power loss will be not so large at high altitude.


Like Charlie and Egn, I am particularly interested in the performance of diesel heaters and stoves not at 2000 m, nor even at 3500 m, but rather, in the 3,500 to 5,500 m range that characterizes the Altiplano and Tibetan plateau.

LoRoad: not sure if you had such extreme high-altitudes in mind, when you first pitched your question about diesel. Your question did not specify a particular altitude range, or a particular continent. So hope that what follows below is consonant with the original intent of your thread.....:)


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1. High-Altitude Highways in Tibet


There is an older ExPo thread titled “Espar Airtronic and Webasto Air Top”, that also discusses the question of diesel heaters and altitude – see http://www.expeditionportal.com/forum/threads/67657-Espar-Airtronic-and-Webasto-Air-Top . Near the end of the thread NothingClever despairs:


Hmm...this thread is a bit disheartening.

Apologies up front if I missed this in this thread or the Webasto website.

The highest altitude discussed here is 7,000ft ASL.

Not to sound snooty, but that's not hard to achieve in North America or South America on a routine trip through, say, Colorado or Peru.

I looked over the Webasto website and although they briefly discuss the Automatic Altitude Adjustment as being standard, their threshold for 'high altitude' is only 2,000m. 2,000m? That's 'high altitude'....really?

Is there a decent diesel solution for altitudes above 10,000ft / 3,100m ASL?


To which dzzz and LanduytG replied:


The Webasto EVO will likely get near 10,000ft. An Espar can be set up with two pumps, with one running very lean. There are installers in the western U.S. who have shops at 6-7000 ft. They would know how to do high altitude.

Espar altitude solutions seems to always reduce fuel flow. I believe the webasto EVO units actually increase combustion fan speed at lower air pressure.

The Espar with the high altitude compensator is good for at least 10K feet. It continuously adjust the pulse of the pump which does reduce fuel to the heater, which does give you less heat out. But most have a bigger heater than needed so reduced output is not a big deal anyway. Stay away from the 2 pump method it just does not work that well.

Webasto use to use more air but I'm not sure if that is still the case, because I have not worked on the lastest model.

IMHO and this is because I work on both, I feel the engineering is much better on the Espar. The Espar is much easier to take apart and repair. However if you don't drastically over size the heater for the space you are trying to heat it will run a long time without issues.


Greg


But even 10,000 feet is not the same thing as 15,000 - 18,000 feet, the upper range of altitude experienced by vehicles driving the Tibetan plateau. For what it's worth, in Nepal 10,000 feet is still considered mere "foothills" country.

As Charlie suggested, the average height of the Tibetan plateau is 15,000 feet, and the mountains rise thousands more feet above that -- http://en.wikipedia.org/wiki/Tibetan_Plateau and http://en.wikipedia.org/wiki/Geography_of_china :


A satellite's-eye-view of India and Tibet. Image from NASA's Terra satellite. Photo credit- NASA.jpg 1941_China_from_the_East low res.jpg


Even the very broad, U-shaped, flat-floored "valleys" in Tibet are still quite high. For instance, Lhasa sits at an elevation of 11,450 feet -- see http://en.wikipedia.org/wiki/Lhasa . The average height of the Altiplano in South America is only a bit lower than the Tibetan plateau, about 13,000 feet -- see http://en.wikipedia.org/wiki/Andes and http://en.wikipedia.org/wiki/Altiplano .

Now here's the thing: the Tibetan plateau has traffic. In fact, lots of it.

For better or worse the Chinese government is massively investing in road infrastructure in Tibet, and the ultimate goal will be a trans-Asian highway that connects China and India, Beijing all the way to Delhi, via the Tibetan plateau – see http://news.bbc.co.uk/2/hi/south_asia/8480637.stm and http://www.seattleglobalist.com/2013/01/30/chinese-highway-forces-tibetan-kingdom-21st-century/9802 :




There is already an asphalt, completely paved highway – the China National Highway 109 – that connects Lhasa with Beijing. See http://en.wikipedia.org/wiki/China_National_Highway_109 and http://www.tour-beijing.com/blog/ti...-driving-along-the-national-highway-no-109-2/ . And there are long-term plans for a Beijing-to-Lhasa 4-lane expressway, about 50 % of which is now open to traffic -- see http://en.wikipedia.org/wiki/G6_Beijing–Lhasa_Expressway . There is another high-altitude highway that runs from Lhasa to the western corner of the Taklamakan desert – see http://en.wikipedia.org/wiki/China_National_Highway_219 . And there is a spectacular, dangerous, but very economically important highway that connects Sichuan with Lhasa – see http://www.dangerousroads.org/asia/china/49-sichuan-tibet-highway-china.html and http://en.wikipedia.org/wiki/China_National_Highway_318 . For more information about Tibetan roads, see http://www.tibettravelguides.com/Roads-in-Tibet.html .

Many of of Tibet's "highways" are gravel roads, but some are not. Compare the following six videos: the first three show paved roads in Tibet, the remaining three unpaved roads:




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2. Boondocking on Lake Manasarovar


The last two videos documented a drive to Mt. Kailash.

Now sure, Mt. Kailash is an exotic destination, but it is also a very desirable one. It is a sacred mountain for Buddhists, Jains, and Hindus alike, and many standard tourist itineraries in Tibet include it. Mt. Kailash lies near the sources of some of the longest rivers in Asia: the Indus, the Sutlej, the Ganges, the Karnali, and the Brahmaputra -- see http://en.wikipedia.org/wiki/Mount_Kailash , http://fr.wikipedia.org/wiki/Mount_Kailash , and http://www.yowangdu.com/tibet-travel/mount-kailash.html .

Tibetan Buddhists think of Mt. Kailash and its surrounding lakes as forming a huge mandala, whereas Hindus think of it as an "Atma Lingam", reminiscent of the Shiva Lingams found on the altars where Shaivates (followers of Shiva) worship -- see http://en.wikipedia.org/wiki/Lingam . Understood philosophically, a Lingam is a symbol of unformed, ineffable divine consciousness taking form. Viewed anthropologically by Western scholars, a Lingam is often described as a phallus, although many consider this a mistaken interpretation. Mt. Kailash is indeed somewhat "phallic", and it does resemble a huge Shiva Lingam, but then many mountains are phallic. Either way, Mt. Kailash is strongly associated with the god Shiva, who is thought to sit at the summit in perpetual meditation, along with his wife Parvati.

So the upshot is this. A truly well-equipped expedition camper, one might think, should be able to take you to the base of Mt. Kailash. And once there, you should be able to boondock for a bit on lake Manasarovar. Also considered sacred, lake Manasarovar sits near the foot of Mt. Kailash, and lies 15,060 feet above sea-level -- see http://en.wikipedia.org/wiki/Lake_Manasarovar . Mt. Kailash itself rises another 7,000 feet above the lake, and is 21,778 ft high, or 6,638 m. In fact, one might want to boondock for at least two weeks, undertaking the 5 - 7 day ritual circumambulation of the lake (a nice hike....:)), visiting the Saptarishi cave on Mt. Kailash, and completing a circumambulation of the mountain itself.

Which means, practically speaking, that a truly well-equipped, globally capable expedition camper should have heating and cooking systems that can function properly for extended periods at altitudes from 15,000 to 18,000 feet, or roughly 4,500 m to 5,500 m above sea-level.

Why 18,000 feet?

The Tang Gu La Pass, through which the Lhasa-Beijing China National highway 109 runs, reaches 17,162 feet, or 5,231 m -- see http://en.wikipedia.org/wiki/Tanggula_Pass . And the highest drivable road in Tibet crosses the "Semo La" pass at 18,258 feet, or 5,565 m -- see http://en.wikipedia.org/wiki/Semo_La , http://www.betzgi.ch/en/route-info/western-tibet/nordschleife/passes/pass/semo-la/ , and http://chelseamorning.wordpress.com/2010/07/21/the-highest-motor-able-road-in-the-world/ . For more about high-altitude drivable Tibetan passes, see http://kekexili.typepad.com/life_on_the_tibetan_plate/2006/12/high_mountain_p.html .

For some beautiful images of Mt. Kailash, see:



Also see http://www.prweb.com/releases/2012/6/prweb9570005.htm , http://www.songtsantravel.com/16-days-kailash-mansarovar-tour.html , and http://www.kailashtourpackage.com/kailash-tour-package.html . The second video suggests just how "ordinary" a trip to Mt. Kailash can be, and describes a "Yatra" pilgrimage in 2012, by a group of Hindus who otherwise live in the United States. YouTube has tons of such "Kailash Yatra" videos -- see http://www.youtube.com/results?search_query=mount+kailash and http://www.youtube.com/results?search_query=mount+kailash+yatra .

If you look through a sampling of such videos you'll see quite a few tour-buses, with Mt. Kailash and lake Manasarovar in the background, although these buses seem to arrive by relatively flat highway from Lhasa, and not up from India -- see http://www.tibetfamilytours.com/kailash-pilgrimage-tour.php . Also notice that many of the roads leading to Kailash and surrounding lake Manasarovar now appear to be paved.

And see http://www.kailashjourneys.com/blog/media/#axzz33eb3e8ib and http://www.kailashjourneys.com/mount-kailash-mansarovar-photos/ for more beautiful imagery:

mount-kailash-overland-tour.jpg 20-Trugo-Gompa-Chorten-With-Lake-Manasarovar-And-Mount-Kailash1.jpg 2.MANSAROVAR-WITH-KAILASH.jpg
gangrenboqifeng(1).jpg Kailash-Mountain.jpg MtKailashNight2.jpg
Mt_Kailash_sat.jpg parikrama.jpg


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3. Chinese, Peruvian, and Bolivian Trucks and Buses


Which suggests a question:

How do trucks and tour-buses that travel the Altiplano and the Tibetan plateau heat their cabins? Do they ever use diesel heaters or pre-heaters? Do they only heat when the engine is running?

See for instance Eberspacher's line of diesel pre-heaters for buses, at http://www.espar.com/products/fuel-operated-heaters/applications/coach-bus.html . Could any of these work at 15,000 – 18,000 feet? And if not, what do Chinese truckers do when they stop for a night on the road to Lhasa?


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4. All-Electric, or Mixed System?


In another thread egn, who owns a wonderful 6x6 MAN-KAT conversion called "Blue Thunder", iterated the sentiments of Haf-E in this thread, suggesting that for ultra-high-altitude capability, all-electric is the way to go, with a generator and massive solar on the roof:


As was already written, such a [hybrid-electric drivetrain] concept is also ideal for an all-electric household, using only one fuel type in the vehicle. Solar power all over the vehicle with a few kWp can fuel the household, and in emergency the car itself at least for a few km a day.

We never liked the idea of diesel hobs, because they are just not as comfortable as typical house-hold appliances, they do smell, and they don't work at higher altitudes very well. Originally they were built for marine use at height zero, and at heights above 2000 m they don't work very well.

We have a normal electrical hob with Ceran surface and with mechanical switches. Induction saves energy, but adds more sources for failures. We save energy when cooking by using other appliances. I.e. we use the microwave to heat a cup of water, an electrical water kettle for heating larger amounts of water, like for cooking pasta. We use our two-sided contact grill to barbecue meat, fish, vegetables, ......

We have a Webasto Thermo 90 ST diesel heater for both space heating and warm water. For warm water we have a boiler that is heated by a heat exchanger or electrically.

Seems like its getting to be a lot of complexity - at some point a small generator and electric appliances, water heater and space heating would make sense... The cost and complexity of multiple diesel heaters (which all require electricity to operate) is another concern - when will a generator/inverter/battery make more sense...


I very much respect the views of both Haf-E and egn, but it's always good to hear a diversity of opinion.

nick_disjunkt, you have a robust combination of both solar + diesel powered heating/cooking, which seems admirable. Redundancy, and being able to choose between alternative sources of heating and cooking energy, seems like a good idea.

But I wonder what will happen to the diesel part of your set-up above 13,000 feet? Are there diesel set-ups that can work above that altitude? And when Espar/Eberspracher and Webasto promise that their newest heaters have "automatic" altitude adjustment, does that include automatic adjustment up to 5,500 m, in the high-altitude kit? See for instance http://www.esparparts.com/techsupport/pdfs/High Altitude Kits/High altitude options 11-2012.pdf , http://www.espar.com/fileadmin/data/countrysites/EB_Kanada/pdf/Off-Highway.pdf , http://www.espar.com/fileadmin/data/countrysites/EB_Kanada/pdf/Bus_ACHeating_Brochure_022613_WEB.pdf , and http://www.espar.com/fileadmin/data/countrysites/EB_Kanada/pdf/Product_Catalogue_05-2014.pdf .

Sure, if one is prone to altitude sickness (many people are), sleeping at 12,000 or 13,000 feet will prove a challenge, and therefore undesirable in any case -- see http://en.wikipedia.org/wiki/Altitude_sickness. But speaking personally, I've slept comfortably at 16,000 feet on treks in Nepal, albeit after having spent weeks acclimatizing first at lower altitudes. And granted, above 18,000 feet it kinda feels weird breathing the thin-air equivalent of skim milk. I've only slept at 18,000 feet for two nights, on either side of crossing a pass at 22,000 feet by foot, in the Dolpo region of north-western Nepal -- see http://www.nepaltravelandtour.com/Trips/Nepal/Dolpo+Region/Trekking/Phoksundo+Lake+Trek/23 , http://www.wildearthjourneys.com/category.php?id=13 , https://www.youtube.com/watch?v=igFZNHz2_vg , https://www.youtube.com/watch?v=V08y1cTAVE0 ,http://en.wikipedia.org/wiki/Dolpo , and http://en.wikipedia.org/wiki/Shey_Phoksundo_National_Park . But the trek was fantastic, crossing that pass was spectacular, and breathing thin air sort of makes you feel lighter.

Many people have similar positive experiences with mountain altitude, and find it invigorating to sleep so high. As the Tibetan plateau becomes increasingly accessible, it will become a place that independent overlanders who enjoy altitude will want to explore, and they will need rigs designed to match.

In short, if anyone knows whether and/or how Bolivian, Peruvian, and Chinese truckers heat their cabins and cook their meals using diesel, at truly extreme “Andean” or "Himalayan" heights in the 13,000 – 18,000 foot range (approx. 4,000 m to 5,500 m), that would be great.... But perhaps they don't use diesel at all?


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LoRoad: I included the highway videos and background info about Tibet, to suggest that driving an expedition camper across the Tibetan plateau is not inconceivable. Indeed, driving across Tibet has become almost too easy, because the Chinese government has been investing so heavily in Tibetan highway infrastructure. And I included the info and images of Mount Kailash and Lake Manasarovar to suggest an extreme-altitutde, 15,000-foot location where it might be nice to boondock for a while. Again, hope all this detailed information that describes an "extreme altitude" scenario was OK.
.
 
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LoRoad

Adventurer
LoRoad: not sure if you had such extreme high-altitudes in mind, when you first pitched your question about diesel. So hope that the above is consonant with the original intent of the thread.:)

To quote one of my favorite movies, "We won't be repressing anyones ideas here today."

While I was curious about these diesel heaters functional altitudes, I wasn't so sure nor had first hand knowledge about how well they work. From what I am hearing, for lower altitudes there seems to be little issue, but at higher altitude it seems to be a crap shoot. Sometimes they seem to work, while others say they don't work so well and sometimes not at all. Because of the uncertainty of the diesel solution, esp. at altitude, I've opted to go all electric. as it seems the most reliable. Of course now that I'vs said that, it'll never work properly (right?)
 

biotect

Designer
LoRoad,

Many thanks for not repressing!..:)

This is a potentially important thread that asks an important question, and it also seems kind of rare. I did a number of google searches trying to find similar discussions elsewhere on the web, but the only thread that reliably came up was the previous ExPo thread already mentioned, titled “Espar Airtronic and Webasto Air Top” - see http://www.expeditionportal.com/forum/threads/67657-Espar-Airtronic-and-Webasto-Air-Top . Sure, that thread also discusses the problem of diesel and altitude to some extent. But it never really answered charlie aarons' or NothingClever's questions, about whether diesel heaters and stoves can in fact handle real altitude, namely, altitude over 10,000 feet.

Your thread, however, is explicitly titled "What is the BEST.....High Altitude Solution for Heating?". So their question can't be avoided on such thread; it has to be addressed at some point. Then thought I'd just amplify their question a bit, making it very clear, explicit, unavoidable. I wanted to make a strong "supplementary pitch" for the extreme-altitude dimension of your question, because it seemed so important.

So let's hope that your thread stays resolutely focused on heating solutions that can handle altitude. That's what makes it truly unique, and so potentially interesting!


**************************************

Now it's very understandable that you've opted for all-electric. But maybe the idea of a “mixed system” is still worth exploring, just a bit further.....

nick_disjunkt
's thoughts about the possible benefits of such a system merit re-quotation:

We've just spent a couple of days at about 9,000 feet in Mexico in our motorhome and had no problems with either of our heating systems.

I have a Webasto Thermo Top 50 which heats water through a Quick BX25 calorifier, and gives a little space heating through 3 small radiators. It has no altitude kit fitted and it worked fine running for a couple of hours each day.

I also have an Eberspacher D2 blown air heater which has the high altitude kit fitted, this also worked fine for several hours each morning, although perhaps a little less effectively than normal.

We have a 550ah 24v battery bank and the impact on the state of charge, even when running both systems all night, is not significant. With 800w of solar on the roof we are always back to 100% by the end of the day if there is some sun.

On very cold days with no direct sun at all, we can get about a week out of our batteries before we get below 50% charge.

The winner for me on using diesel for heating is the quantity of fuel that you can carry with you. We have a 250 litre aux tank for heating and the generator and in 3 months on the road, we still have about half the tank left. That's with a fair amount of cold weather and hot showers every day.

So perhaps the ideal would be a dual-fuel system, in which the heater can be run off either diesel or electricity? The heater would run off solar-generated, dual-alternator-generated, or generator-generated electricity when at extreme altitudes (say, above 11,500 feet); but fed directly by diesel fuel when traveling at altitudes below that.

Dual-fuel LPG combination space-heater/water-boiler systems do exist, for instance, Alde's 3010 Compact HE Combi – see http://www.alde.co.uk/itemdetails.php?itemId=1 and http://www.alde.co.uk/downloads/alde_cat_21.pdf . Alde explicitly advertises that this heater is:

“Powered by LPG and/or 230 V electricity.”

Like other systems, Alde's heating system can also be fitted with a heat exchanger, that transfers engine heat to the central heating system while on the move – see http://www.alde.co.uk/alde-compact-products.php?itemCat=alde 3010 compact system and http://www.alde.co.uk/itemdetails.php?itemId=58 .

I looked through the Eberspracher and Webasto websites at length, but could not seem to find that “magic” combination of words, as per Alde:

“Powered by Diesel and/or 230 V electricity.”


But perhaps I am missing something?

Does anyone know whether either Eberspracher or Webasto make a “dual-fuel” heater, that can be powered by either diesel or electricity? Or do any other manufacturers make such a heater? Such a heater seems like the optimal solution.

BTW, also ran across the following description in an Eberspacher brochure:

Special plus points of Hydronic M:


  • Service life twice as long (6,000 operating hours)

  • automatic altitude adjustment of the Hydronic m10 / m12 up to 3,500m.

See http://www.espar.com/fileadmin/data/countrysites/EB_Kanada/pdf/Hydronic_M-II_Spec_sheet.pdf and http://www.eberspacher.com/applications/motorhome.html . Download the “Heater Range Commercial Brochure”, and you'll find the above bit of info at the bottom of page 11. And see the very useful pdf at http://www.esparparts.com/techsupport/pdfs/High Altitude Kits/High altitude options 11-2012.pdf , where for the Hydronic MII-10 and MII-12 the chart says "Nothing Required/Automatic Adjustment", i.e. no additional high-altitude kit needed.

3,500 m is 11,500 feet, and sure, it's not 13,000 feet or 15,000 feet. But it's still substantial. And built-in automatic altitude-adjustment up to such an altitude would save a few headaches.

But once again, what really seems wanted is a diesel dual-fuel heater, akin to the Alde's LPG dual-fuel, and one that includes automatic altitude-adjustment up to 3,500 m. And one that perhaps automatically switches over to electricity above 3500 m....:)

All best wishes,


Biotect
 
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julius0377

Adventurer
Redundant heating and other stuff

Heating the inside of the box - Webaso Dual Top (mounts outside under vehicle, dual heat and small water tank (11 liters, hot water from this unit could be used in kitchen exclusively?), unit allows venting to be very easy throughout the cabin. uses diesel.

If you are using an alternative heating source in winter (say electric at a campground, where you want to limit diesel exhaust), an outside placement of a Webasto heater with a water tank may lead to freezing and damage to the tank. (Unless it has auto or manual water dumping, without affecting the overall water flow when shut down.)

A rare situation to be in (winter at a campground with neighbours.)

Also if you are heating the rear box (camper) with a heat exchanger from the engine and not using the Webasto, you could get the same type of issue. In temperatures below freezing, the webasto with water tank mounted outside will either have to be heated in some way, drained or always turned on.

Maybe there is a way to mount it using bypass valves to drain only the outside mounted webasto, and not the whole system?

Secondary/Redundant?
Engine - Webaso Thermo Top - integrates with the engines water circuit and can heat the cab as well, can be operated remotely from w/in the box.

I would go for a redundant water heater like this with a heat exchanger to the camper box. This way you have redundant heating on a diesel source, in a configuration that heats both the box and the cab. As well as being able to heat the box while driving and not using the webasto (if the engine produces enough excess heat in cool temperatures.)

You can find a range of eberspacher heat exchangers by downloading the pdf called “Brochure Convectors” from this site: http://www.eberspaecher.com/en/download-center/brochures/fuel-operated-heaters.html

The webasto diesel heater with hot water boiler gives 11 liters of hot water. The Truma Combi D6E system for diesel gives 10 litres, and is a good option if you are using other Truma systems onboard (aircon) as they benefit from using the same control panel. The Truma diesel heater has a high altitude kit as an option. http://www.truma.com/int/en/heating/diesel-heater-combi-d-6-e.php

The Saphir Vario aircon together with a kit and a sinus power inverter gives you the option of cooling the camper box using the vehicle alternator while on the move (engine running). Your alternator needs to be dimensioned accordingly but I guess your vehicle should accommodate this. You can also run it of the batteries, but this drains them at a fenomenal speed. http://www.truma.com/int/en/air-conditioning/saphir-vario.php

German company Elgena has water boilers like the Isotherm for both pressurized and non pressurized systems. With a lot of different options for energy sources. You get 12/230v, 24/230v, some that you connect inline with the heated air from a webasto as well as 12v, etc. In many sizes. I have no experience with these. http://www.elgena.de/index.php/produkte/druckfeste.html
 

Joe917

Explorer
According to the previous owner of our vehicle the Webasto unit worked fine at altitude but the generator struggled . Our water heater(Isotherm) that runs off the Webasto also has a 230 volt element so using that with a pump to move the coolant you should be able to heat with it. Producing power for a 230 volt heating system from a generator may be as bigger problem at altitude.
 

julius0377

Adventurer
Another related topic is air vs. water heating. I notice that many of the luxury EV producers (Action Mobil, Unicat, etc.) go for water heating of the camper box. Personally I prefer air heating for winter climates with this in mind:

*Dries out the air inside, so if you have wet clothes etc. they dry faster.
*Easier self maintenance/repairs, simpler construction.
*Reaches a warm air temperature quicker (depending on a lot of factors of course).

Make sure you have a lot more air outlets than you think you need. The more you have the better. Typical serial produced campers are delivered with too few air vents, and have issues with too high air flow volume from each outlet, dust particles being blown around, etc.

Another tip is to lay your cold water line near the air heating pipes, this makes them not freeze in winter. But not too close, then it can take a while of wasted water for it to be cool at the tap. Do not lay the hot water and cold water pipes next to eachother. The heat from the hot water pipe will heat the cold water to lukewarm, and give you unpleasant lukewarm drinking water in the summer (again wasting the water in the pipe until cold water from the tank arrives at the tap.)
 

biotect

Designer
.
Producing power for a 230 volt heating system from a generator may be an even bigger problem at altitude.

Yeah, I've been wondering about that too. Unless one runs the heating system off solar, at some point in the circuit diesel combustion has to generate the energy.

First off, it's worth noting that diesel cars tend to perform better than gasoline-driven cars at high altitudes, because most diesel cars nowadays are equipped with turbochargers that ram air into the engine -- see http://www.anl.gov/articles/five-myths-about-diesel-engines .

But of course most diesel generators are not equipped with a turbo-charger, and they are positively primitive in comparison to automotive engines:

Generally speaking, any internal combustion engine loses efficiency with altitude. Nothing demonstrates this more vividly than motorboats. Water applies such tremendous resistance that a 100MPH boat at sea level will only achieve 85MPH at a mile high…..

Modern engines with electronic fuel injection and ignition mitigate this to a point. But most generators do not have the bells and whistles of an automobile engine. Oxygen sensors, altitude sensors, air temperature sensors, humidity sensors and so much more goes into electronic engine controls.

The typical one-lung genset engine is nothing more than one found on a typical lawn mower. About the only way you could overcome the altitude issue would be with a turbocharger. The cost of that would buy a bigger genset.

See https://eplaya.burningman.com/viewtopic.php?t=34876 .

The Onan QuietPower Diesel 10,000 watt will derate 3.5% for every 1,000' over 500', and it further derates by 1% for every 10° F increase in temperature over 85° F. A good rule of thumb for most gensets is that you will lose 10% of the rated output every time you gain 3,000' in altitude. This means that a 7,500 watt generator running at 9,000' of altitude will only be capable of producing a bit over 5,000 watts at that altitude.

See http://www.rvtechlibrary.com/generator/altitude.htm .

With that said, in the world of generators specifically, diesels are much less fussy at higher altitudes than gasoline-driven, because diesels run fuel-lean, so the air-fuel ratio does not have to be kept perfect. Whereas gasoline engines operate at a very specific ratio of fuel to air. As a consequence, for instance, the gasoline generators that Cummins-Onan sells have an altitude-compensation adjustment on the carburetor -- see http://www.rvtechlibrary.com/generator/altitude.htm . Also see http://thesurvivalpodcast.com/forum/index.php?topic=7034.0 .

Some will say that modern diesel generators used in RV’s should have no problem aside from power loss up to 12,000 feet – see https://eplaya.burningman.com/viewtopic.php?t=34876 and http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/24998400/print/true.cfm . But one short warning I came across suggests that, without turbocharging, there is much less air to compress at higher altitudes, so less heat is generated, so there’s less combustion (ergo loss of power), and the resulting incomplete combustion damages exhaust systems and shortens engine life – see http://www.emergencypower.com/support/generator-buying-guides/181-high-altitude-diesel-generator-use . This particular website then recommends that one should not buy a diesel generator for use above 3000 feet; or at the very least, not one without a turbo-charger. Also see http://ezinearticles.com/?High-Altitude-Diesel-Generator-Use&id=3116820 .


*********************************

Diesel Genset at High-Altitude in Antarctica


Those reading this who are a bit geekish, and who enjoy reading about interesting technical solutions to extreme problems, might find it worthwhile to take a look at the diesel-generator solution arrived at by “PLATO”, the automated or “robotic” observatory located at Dome A on the Antarctic ice-cap. It’s one of the coldest, highest, and most remote sites in Antarctica – see http://spie.org/x30348.xml , http://mcba11.phys.unsw.edu.au/~plato/enginemodule.html , http://www.phys.unsw.edu.au/jacara/Papers/pdf/Hengst.pdf , http://web.science.mq.edu.au/~jsl/cv/C08_SPIE_PLATO.pdf , http://mcba11.phys.unsw.edu.au/~plato/papers/lou10a.pdf :


1284_fig1.jpg


Dome A’s elevation is 4,093m, and it’s 1600 km from the coast. But low temperatures in Antarctica mean that atmospheric pressure falls off more rapidly with altitude, and so average air-pressure at Dome A actually corresponds to a “pressure altitude” of 4,530 m for more temperate climates. There’s inadequate wind at Dome A, so wind-power was not an option. 6 months of the year there’s also no sun, so although solar was set up, it’s usable for only half the year. And temperatures at Dome A run as low as - 80 degrees C in the winter.

The power-generating solution that an Australian team arrived at is an automated bank of six small Hatz 1B30 air-cooled four-stroke diesel engines, arranged in two banks of three, mounted on a 4000 liter fuel tank – see http://www.hatz-diesel.com/en/products/diesel-engines/b-series/product/details/name/1b30/ , http://www.hatz-diesel.com/uploads/tx_hatzproducts/TB_1B_70252829_EN.pdf , http://www.hatz-diesel.com/fileadmin/user_upload/hatz-diesel.com/brochueren/Hatz_Motoren_EN_2013.pdf , and http://www.hatz-diesel.com/fileadmin/user_upload/hatz-diesel.com/brochueren/Hatz_Systems_EN_13.pdf :


enginemod_600.jpg 1284_fig2a.jpg


Although the engines were rated to produce 5 KW at 3600 RPM at sea-level, the Australian team decided to deliberately run them slower, at 2200 RPM, to reduce engine wear. They then expected a maximum power output of 2 KW at 4,530 m above sea-level. Incredibly, they ran the engines on A1 Jet-Fuel instead of diesel. But of course Jet-Fuel suitably enhanced for compression-ignition engines. For batteries they used ultra-capacitors instead of lead-acid or lithium.

They found that they had to make only very slight modifications to the diesel engines so they could operate at 5000 m, and the engines were almost as "efficient" at high-altitude as at sea level, albeit producing much less power.

Also see an interesting discussion regarding provision of a diesel generator for a new observatory in the Andes, located at 17,000 feet –https://uk.answers.yahoo.com/question/index?qid=20061012161640AAEDSyG .


*********************************

The critical thing, it seems, would be to research which standard RV diesel generators are truly altitude-capable, and which are not. Here it would be worth researching Cummins-Onan, Kohler, Kubota, Martin Diesel, Whisper Power, Fischer Panda, and Hartz. Do any of these manufacturers sell specific models of diesel generators equipped with turbochargers? Any other manufacturers of generators worth considering?

I am not an engineer, so the above is just stuff that I was able to find on the web. But this is a topic that interests me greatly, because "Tibetan plateau capability" is an important design-paramater for the expedition motorhome that I will be designing for my MFA thesis.

For an interesting thread that discusses driving Landcruisers across the Tibetan plateau, see http://www.horizonsunlimited.com/hubb/4wd-overland-tech/high-altitude-and-diesel-engine-20169 . Now just need to find a thread that discusses driving across the Tibetan plateau for trucks, buses, or (if it even exists!) motorhomes....


LoRoad: Is a high-altitude-capable diesel generator part of your current specification? If so, which manufacturer are you inclined to choose? And it would be great if you could share any additional details about the “all-electric” high-altitude solution that you currently have in mind.

All best wishes,



Biotect
.
.
 
Last edited:

biotect

Designer
Julius0377,

Great leads!

Here are some responses:

The Truma diesel heater has a high altitude kit as an option. http://www.truma.com/int/en/heating/diesel-heater-combi-d-6-e.php .

I found the kit, but it states “For longer heater operation at elevations of 1500 to 2750 meters.”

2750 m is not “high-altitude”; it's still just 9,000 feet high. Most of the Altiplano is above that. See http://www.truma.com/int/en/heating/accessories-heating-systems.php , bottom of the page, and http://www.truma.com/downloadcenter/hoehenset_installation_instruction_de_nl_fr_it_gb_dk_e.pdf .


**********************************

German company Elgena has water boilers like the Isotherm for both pressurized and non pressurized systems. With a lot of different options for energy sources. You get 12/230v, 24/230v, some that you connect inline with the heated air from a webasto as well as 12v, etc. In many sizes. I have no experience with these. http://www.elgena.de/index.php/produkte/druckfeste.html

Excellent lead for compact water-boilers. But wouldn't it be better to have a combined system like Alde or Truma, a system that heats water for the shower and kitchen + simultaneously heats water for passive radiator heating?

I am not sure about this, so it's just a question. Would like to know your opinion.

Came across the following interesting build-description, for a van conversion that spent a lot of time in the Andes – see http://dinoevo.de/diesel-coolant-heater-hot-water-tank/ . They combined an Eberspracher Hydronic D4 heater with an Elenga Nautic-Junior M water boiler with 10 litre capacity, in a system that even they describe as “complicated”. Also see http://translate.google.co.uk/trans...u=http://www.elgena.de/index.php/produkt.html , http://dinoevo.de/about/ , http://dinoevo.de/modifications/ , http://dinoevo.de/gallery/ , http://dinoevo.de/category/interior/ , etc.


**********************************

The [Truma] Saphir Vario aircon together with a kit and a sinus power inverter gives you the option of cooling the camper box using the vehicle alternator while on the move (engine running). Your alternator needs to be dimensioned accordingly but I guess your vehicle should accommodate this. You can also run it off the batteries, but this drains them at a fenomenal speed. http://www.truma.com/int/en/air-conditioning/saphir-vario.php .

This sounds excellent as a solution for A/C, especially given that high-output “dual alternator” set-ups seem more or less mandatory for expedition vehicles. Earthroamers have dual alternators, as does egn's MAN-KAT 6x6 “Blue Thunder”. Also really nice that the Truma Saphir A/C is the “world's only air-conditioning system that can be installed in a false floor”, because its installation height is just 20 cm. Good to know about.

I haven't thought much yet about A/C, but it seems like it's one of the really big energy-drains for a camper. From what I've read so far, it seems that even with a roof covered in solar panels and a big battery bank, it is still "challenging" to run A/C off-grid in a very hot climate. Some kind of supplement for solar still seems needed, so having the option of running the A/C off either the vehicle's main engine (via dual alternators), or the diesel generator, would be important.


**********************************

So still looking for a combined heater/boiler, similar to the Alde, one that is truly “dual fuel”, and can run on 220 V electricity wihout diesel when the vehicle drives above 11,000 feet.

Looked at the Truma Combi heaters 6 and 6E, which at first seem to be “diesel-electric” – see http://www.truma.com/int/en/heating/overview-diesel-electric-powered-heaters.php . Investigating the Combi 6 and the Combi 6E further, found that yes, both come in diesel-fueled versions, and both seem to combine warm air heating with hot-water heating and a 10 L boiler. So well near perfect, and they seem to be just what you might be looking for, Julius0377, because you prefer forced-air heating systems as against of water-radiator systems – see http://www.truma.com/int/en/heating/diesel-heater-combi-d-6-e.php and http://www.truma.com/int/en/heating/diesel-heater-combi-d-6.php .

But the Truma Combi 6 and 6E are “diesel electric” only in the sense that the fan that drives the warm air, and the motor that drives the water pump, are electric. Unlike the Alde, they cannot work with 240 V electric power alone. And of course they are limited to 2,750 m of altitude, or 9,000 feet.

So still looking……

But many thanks,



Biotect
 
Last edited:

julius0377

Adventurer
Truma/Webasto specs etc.

Julius0377,
Excellent lead for compact water-boilers. But wouldn't it be better to have a combined system like Alde or Truma, a system that heats water for the shower and kitchen + simultaneously heats water for passive radiator heating?

It seems we are on the “no gas/lpg” in EV's deal, and I know of no diesel powered water heaters. So I would advocate a combined system like webasto/alde/truma/eberspacher. I do find the 10-12 liters in the combined systems to be on the small size, therefor a complimentary water boiler is good both for redundancy and added capacity. All depending on your needs.

Julius0377,
From what I've read so far, it seems that even with a roof covered in solar panels and a big battery bank, it is still "challenging" to run A/C off-grid in a very hot climate. Some kind of supplement of solar still seems needed, so having the option of running the A/C off either the vehicle's main engine (via dual alternators), or the diesel generator, would be important.

Keep in mind also that the biggest added benefit of an AC it not neccesarily lowering the temperature, but drying out the air. As an example in 30 degree weather, I would set my AC to 28 degrees. This will dry out the humidity and making the interior a much more habitable space while using a lot less power than cooling all the way down to say 22 degrees. The “heavy duty” standard alternator i have in my Atego gives 100 amps at 24 volts, this converts to 2400 watts (a bit less due to loss in conversion etc.) But should be enough for both charging the batteries, running a Saphir Vario AC as well as a fridge and other accessories. The alternator puts out enough only at higher rpm's, so the vehicle would have to be in motion, not standing still with the engine on.

Julius0377,
So still looking for a combined heater/boiler, similar to the Alde, one that is truly “dual fuel”, and can run on 220 V electricity wihout diesel when the vehicle drives above 11,000 feet.

Looked at the Truma Combi heaters 6 and 6E, which at first seem to be “diesel-electric” – see http://www.truma.com/int/en/heating/overview-diesel-electric-powered-heaters.php . Investigating the Combi 6 and the Combi 6E further, found that yes, both come in diesel-fueled versions, and both seem to combine warm air heating with hot-water heating and a 10 L boiler. So well near perfect, and they seem to be just what you might be looking for, Julius0377, because you prefer forced-air heating systems as against of water-radiator systems – see http://www.truma.com/int/en/heating/diesel-heater-combi-d-6-e.php and http://www.truma.com/int/en/heating/diesel-heater-combi-d-6.php .

But the Truma Combi 6 and 6E are “diesel electric” only in the sense that the fan that drives the warm air, and the motor that drives the water pump, are electric. Unlike the Alde, they cannot work with 240 V electric power alone. And of course they are limited to 2,750 m of altitude, or 9,000 feet.
t

This is incorrect, the Truma Combi 4E and 6E (gas) and D6E (diesel) all have 1800 watt electric heating elements that run off 240v grids. This means you can run one with an inverter if you have enough electicity available (generator or alternator when driving.) Other benefits are heating both water and interior using only electrical hookups when at campgrounds. It should be said that 1800 watts of heating is not enough for very cold temperatures, in these instances you can run them on combined gas/diesel and electric operation, where the truma will favour electric and start using gas/diesel only if it cannot reach the desired temperature on electricity alone.

I could not find out if the Webasto Dual top can heat without having water in the boiler (like Truma). If they can they are similar in most respects with a slight nod to Webasto for maximum heat output. The Webasto can be mounted outside, but this to me seems not to be a good way to go if one uses other heat sources as well for the box like heat exchangers from the engine. In these cases outside installation will make the Webasto drain the water (auto drain) if I'm not mistaken?
 

julius0377

Adventurer
Dual setup/redundancy

Came across the following interesting build-description, for a van conversion that spent a lot of time in the Andes – see http://dinoevo.de/diesel-coolant-heater-hot-water-tank/ .

This seems like a good option for a van where you want to fulfill all of these criteria:
*Water heating system (not air)
*Smallest possible size
*Engine heating
*Box heating with both Eberspacher/espar as well as excess engine heat.

It does not cater for the redundancy a large expedition vehicle should have (multiple heating options/sources).

So still looking for a combined heater/boiler, similar to the Alde, one that is truly “dual fuel”, and can run on 220 V electricity wihout diesel when the vehicle drives above 11,000 feet.

Seems to me your options are these:

Webasto Dual Top:
Air box heating from diesel
Water heating from diesel
240v heating element for both air/water (may not be sufficient in very cold temperatures)

Eberspacher or webasto with calorifier:
Water convector box heating with diesel
Engine heating with heat exchanger
No secondary fuel option for heating
Calorifier may have secondary heat source (electric) depending on brand.)

Alde:
Water convector box heating from gas
Water heating from gas
240v heating element for both air/water (may not be sufficient in very cold temperatures)

Truma Combi 6E:
Air box heating from gas
Water heating from gas
240v heating element for both air/water (may not be sufficient in very cold temperatures)

Truma Combi D6E:
Air box heating from diesel
Water heating from diesel
240v heating element for both air/water (may not be sufficient in very cold temperatures)

The gas variants (alde/truma) may not have the same issues at very high altitudes (my Truma Combi 6E does fine in the highest plateaus in Norway, I could not find any sources for info on gas heating at very high altitudes). This could be a good option for very high altitudes. You would need a large LPG tank to accomodate for the LPG consumption at very cold temperatures.

If I had no cost or space restraints, my “dream" system would probably look something like this:

Engine and cab heating from a large Webasto or Eberspacher diesel heater, with a calorifier and heat exchanger to the box. There would need to be some advanced plumbing going on here (may not be feasible, I’m no expert at this…)
Box heating from a gas system that also runs on 240v. Probably a Truma or Alde (air or water) with integrated boiler.

This gives you redundancy, and you can run diesel or gas as you wish depending on availability and altitude. You get all the benefits:
Heating of the engine before starts in cold climates
Extra heat output for the cab in cold climates
Heat exchanger for the box when you are driving
Heat exchanger for the box when standing still and you want to use diesel as fuel
Calorifier for hot water when you want to use diesel as fuel
Heating of the box with gas
Heating of the box with electricity (240v)
Heating of water with gas
Heating of water with electricity (240v)

You would need 1 part to be installed near the engine (webasto/eberspacher), and three parts inside the box (heat exchanger, calorifier and Truma/Alde) This means a fairly large EV!

In the above case, if you go for Truma, the heat exchanger could be air to air and use the same piping to distribute the warm air. If you go for alde, you could maybe use the same convectors for both the Alde and the Webasto/Eberspacher?

Downside to all this is complexity. A simpler solution would be to forego engine heating (there are other options for cold start help, something you do need at very cold temperatures, but not cab heating without the engine running). Drop the whole heat exchanger business (thus no sharing of engine heat with the rear box while driving). And go for a simple dual setup, one webasto or eberspacher air heater, connected to the same pipes as a Truma gas heater with 240v. You can heat the air with both gas/diesel/electricity as you wish, but only heat the water with gas or electricity.

At present I have a Webasto for the engine/cab, and a Truma Combi 6E for the box. I'm looking into a heat exchanger for heating the box while driving, (and having diesel as a secondary heatsource should the Truma fail at some point where repairs are difficult.)
 

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