Parking heaters at altitude

Lovetheworld

Active member
We have a Planar 2kW diesel air heater, and I don't know at what altitude I have used at the highest. But 9000ft is nothing special.
I think I probably used it a few times above 10000ft.
I believe it does not come with height adjustment and it works fine.
 

Ramdough

Adventurer
So, just to clarify.....

These heaters “work” at high altitudes without modifications, but they will run rich and coke up the burn chambers. They will eventually have issues as that layer builds up. So they will “work” for a while, but then you have to eventually take it all apart and clean it.


Sent from my iPhone using Tapatalk
 

IdaSHO

IDACAMPER
Yep. And as I said, you must sort out the air:fuel mixture to keep things happy.

Our LP even in severe cold and 10k elevation would do "okay" but there was obvious soot from the exhaust side, so the mix was obviously rich.
Adding an adjustable regulator and some trial/error fixed the issue. A clean burn, provided by the proper air:fuel mix is a reliable and safe burn
 

Christian P.

Expedition Leader
Staff member
Looks like I may have found the answer I was looking for:


"To tune for elevation, you reduce the fuel pump rate (hertz) by 4% per 1000 ft gain. The air RPM is not adjusted for elevation in most cases."

I am not sure what the baseline is though. The default Hertz is 1.6. The range is 0.8 to 2.5

There is a Facebook group that's apparently pretty active and should have more info. I am awaiting the approval...
 
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Trail Talk

Well-known member
Unicat supplied me with an incredibly simple altitude adjustment for my Thermo Top C. 2 T fittings and a finger controlled needle valve. A “short circuit” between fuel supply and return. Open 1 revolution for each 1000m above 2000m.
Do you have more info or a schematic for this? Sounds like a great mod!
 

roving1

Well-known member
Some wiz with an arduino needs to make an open loop map with a fuel injector and user inputted altitude for one of these or a closed loop with an O2 sensor or MAP sensor. With how finicky these things are and the price for the original non-Chinese knockoff versions I am surprised they don't come this way from OEM's.
 

Joe917

Explorer
Some wiz with an arduino needs to make an open loop map with a fuel injector and user inputted altitude for one of these or a closed loop with an O2 sensor or MAP sensor. With how finicky these things are and the price for the original non-Chinese knockoff versions I am surprised they don't come this way from OEM's.
Altitude is not an issue for the vast majority of these units. The high altitude visiting overland vehicle is a tiny percentage of the market.
 

86scotty

Cynic
Not sure what I'm looking at. Of course I see a pool of dirty melted water, could be soot but maybe not. Can't tell what surface is under snow. What is the hose? That doesn't look like a furnace exhaust and why would it be down in the snow?
 

Victorian

Approved Vendor : Total Composites
We have a Planar 2kW diesel air heater, and I don't know at what altitude I have used at the highest. But 9000ft is nothing special.
I think I probably used it a few times above 10000ft.
I believe it does not come with height adjustment and it works fine.
All pending when and where you bought it, the planar already came with a build in altitude compensator.
we run ours without compensator often above 10000ft. The output was reduced but no issues. After 2 years we sold the vehicle without having a single issue with the planar.
we are now on the newest model in our transit. Running it only on kerosene. Also installed the new touch screen controller and fob to start remotely.
 

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Rico59

New member
So I am camping right now in Colorado as I am driving the Ford Transit Expo van across country and stopping along the way to do some late season snowboarding.

I have a cheap 12V heater self contained that I just installed temporarily in the van as a stop gap measure. The GPS says I am at 9700ft right now.

The heater started fine (after I unplugged the exhaust and inlet that were full of ice & mud, but that's a different story).

I was under the impression that I may have to adjust it, but it seems to be running just fine. I know who to enter the advanced mode to change the frequency. The default is 1.6

Just out of curiosity, if I had to adjust it, would it need to go down or up?

The pump frequency should drop by approximately 9% every 1000 meters of altitude, to maintain the optimum air / fuel ratio as above sea level; clearly decreases the power of the heater.
 

Rico59

New member
Hello everyone, I have been following the topic carefully and I am sharing my experience. During the construction of my truck I installed two new Eberspacher D5WSC Hydronic 24V boilers + 1 Eberspacher Airtronic D4 24V (all with high altitude kit 22.1000.33.22.00), but when I started using it I realized that the high altitude kit it did not work on the 2 Hydronic D5WSC boilers. I asked Ebespacher for clarification in Italy and Germany, but no one was able to give me precise answers .... Then I found the definitive answer on the internet. The high altitude kit 22.1000.33.22.00 only works with preheaters that have the H-Kit code on the plate, but have never been produced in 24V. For this I have created an electronic controller that automatically adjusts the flow rate of the diesel pump taking into account the altitude, keeping the stoichiometric air / fuel ratio constant even when going to the mountains ... It works very well because it is progressive, intelligent and dynamic. Works with Webasto, Eberspacher and recently also tested with Truma Combi Diesel 12 and 24 v. No changes to preheaters and their electrical systems. If anyone is interested please contact me scalcon.riccardo@gmail.com. The system has already been running in my truck for 2 years.
 
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The very simple Unicat supplied modification to my Webasto Thermo Top C (diesel ) was slightly incorrectly described by me. The fuel “short circuit” that’s controlled by the needle valve runs from the fuel supply downstream from the pump to fuel supply on the tank side of the pump. There’s no fuel return line.
Haven’t had a chance to try yet above 2000m.
Obviously it’ll reduce output.
 

javajoe79

Fabricator
Some wiz with an arduino needs to make an open loop map with a fuel injector and user inputted altitude for one of these or a closed loop with an O2 sensor or MAP sensor. With how finicky these things are and the price for the original non-Chinese knockoff versions I am surprised they don't come this way from OEM's.
I plan on something like this plus completely controlling the entire heating system and all the other power in the camper using a PDM from Hardwire. It will take some figuring out but it should eventually work perfectly and be controllable via wifi.
 

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