Chinese diesel heater altitude settings

[Youngster]

This is one of the better manuals out there for 2kw CDHs. Most of the Chinese manuals are unintelligible.
Even though this manual is for the smaller unit the instructions are generally the same for both 2kw and 5kw sizes.

[Youngster]

I finally got to put my 2kw CDH through the paces in the Sierra this week.
I'm running an 'Afterburner' controller connected to my phone via blue tooth, the controller gives me the case temperature from a sensor on the heating body.
My CO readings at the muffler end were taken with a Klein ET110 CO Meter. The exhaust was passed by the sensor using a empty paper towel roll with the sensor punched though the middle to concentrate the exhaust over it.

Following the case temp and CO readings help me know how optimally the CDH is working for a given setting. This way I can avoid bad settings at altitude that may soot and plug up the heater.

Home Setting (500ft)
Low range setting 1.4 hertz, 2000 rpm - High range setting 3.2 hertz, 3500 rpm. This works good for me. No smoke start.
High power (set to 3.2 hertz) gets the case to ~380*, 120ppm CO. Lower Power (2.2 hertz power setting) 330*, 40ppm CO

(4% per fuel reduction per 1000 ft gain suggested by various sources on the web. Turned out to be too aggressive an adjustment for me. Went with my own numbers.)

Using kerosene/diesel mix, equal parts

No air RPM adjustments were made for elevation, only fuel was adjusted.

Fossil Falls, 3000ft (home setting range used, 1.4 - 3.2): At 3.2 hertz power setting, 394*, 120-150 CO. At 1.8 hertz power Setting = 40 CO

Lundy canyon campground, 7500ft. 25* outside in the morning. Total run time about 14 hours this day.
Used: 1.2 - 2.8 hertz range
At 2.2 hertz power setting = 365*, 80-120 CO
At 1.6 hertz power setting = 330*, 30-40 CO
At 1.4 hertz power setting = 315*, 30-40 CO (case temp too low, turned power/fuel Hz down too low)

Bridgeport Marina campground 6500ft. 14* at sunrise. Total run time about 14 hours this day.
Used: 1.3 - 2.9 hertz range
At 2.9 hertz power setting = 397*, 80-100 CO
At 2.4 hertz power setting = 354* -- no CO reading taken (too cold!)

Hope that makes sense. A lot of numbers and screaming kid in the background don't mix!

[arctictraveller]

Originally Posted by Youngster

. Following the case temp and CO readings help me know how optimally the CDH is working for a given setting. This way I can avoid bad settings at altitude that may soot and plug up the heater.

Nice work on the data collection. I just started testing my 5kw, but I pretty much have zero understanding of the pump settings. The manual is really hard for me to comprehend when it discusses how max and minimum fan speed relates to pump speed. I understand that reducing fuel pump volume as altitude increases or fan speed decreases will result in a leaner, cleaner burn, but I haven't figured how this can happen automatically when in one of the two temperature control modes(manual or automatic) or how to decide on the settings without a CO meter. How do the CO readings relate to burn efficiency? In a gasoline engine, too lean a burn can result in melting pistons in extreme cases, is there a similar danger with heaters?.

[Youngster]

I had to read the FB CDH groups for days to glean the nuggets that made sense of these things. I figured if I can rejet a dirt bike for elevation I should be able to figure this out.

The thing to keep in mind is the combustion process in these heaters involves no moving parts. You don't have to worry about seizing them up, all you have to worry about is sooting. Once this point is realized, it changes the whole concept. Dust in the intake?... not a big deal. Too lean?... won't kill it.

Most people don't use a CO meter to figure out settings. But I wanted to know if my heater is blowing xxxx ppm of CO for two reasons: 1) at that level of CO it might find a way into the van, 2) at that level of CO sooting will occur. Then dependability becomes a concern.

I use the manual settings to control the CDH output. These are shown as hertz settings (x.x hz) on the display. I predict what I need for output and let it ride. If I need more or less I adjust using my Afterburner phone app. (But never setting it too low, to keep the case temp up. Case temps should stay higher than 305*f preferably ~390*f). Sounds complicated but it's not. Just run the CDH for 15 min, see what the case temp settles into, adjust accordingly. Not a big deal in my sleeping bag to adjust on the fly if I feel to too warm or cold.

From my experience using the temperature setting runs it on the highest setting (from the hertz range) until the selected temperature setting is reached then it throttles back to the lowest setting until the temp drops down below your set temp then back to high again. It never turns off, just oscillates between high and low. The problem here, I'm a little fuzzy on this, is that the low range hertz setting for the CDH is involved in the starting protocol. If set optimally for starting the min 'hertz range' setting is too low to idle the heater at (low case temp, sooting), if the min 'hertz range' setting is set higher for a higher idle temp then the starting process is too rich with fuel and smoke bombs out everyone in the area from the muffler, overwhelming the glow plug. Starting may or may not happen, sooting can occur.

The short of it is that I use the manual setting and it's easy like that.

[Youngster]

Concerning the air RPMs.
I treat that setting as more of an adjustment for the heater build, intake and exhaust pipe configuration. For example, no more than 6 feet of exhaust pipe length is recommended and no more that 270* of turns (intake has similar considerations). My exhaust pipe turned out to be 8 feet to get the exhaust end out from under the van. My settings were not working and I was getting a sloppy, smoke bomb start every time. Turns out the extra 2 feet of pipe created enough back pressure to mess up my bench test settings. I increased the air RPMs by 700 and the problem went away and is now dependable. Now my air/fuel adjustment are only to the fuel side of the setting range.