Bunk Heater in -40

I don't use the bunk heater if it's below -15.

 

You'll need two sets of thermal sleeping bags, thermal underpants, socks, sheets, etc. If working as company-driver consider that bunk heater defective. Good luck.

 

Seems like my 2kw starts struggling at 15 degrees. Maybe 4kw is better. I personally just idle when it's below 15 degrees

 

In my experience those tiny lines will jell before every thing else. And yes adding and using winter fuel. Keep running if 0F or less

 

Exactly, I use the bunk heater to -10'c max, then run the APU on heat, and have the bunk heater cycling, at about -25-26'c I need to idle the truck (The APU can't keep temp) anything minus -30'c you need to high idle the truck and use antigel. I left my truck parked for days off last year, in that -40'c to -46'c cold snap we had (APU and Bunk Heater going full tilt) and the bunk heater froze (not just the lines, but the whole heater!) and the APU on high heat, could only keep that cab at -5'c. It kept the engine warm tho, and she started up on the first crank, but it took almost 45mins of low/high idling to get to temp, and my air compressor/dryer weren't happy (I drained the tanks when I parked, just trying to compress air that cold is hard on things). If you try to just use a bunk heater in -40'c your truck is going to be frozen underneath you. Even an engine heater, won't keep the air system warm.

 

I woke up to -30F nice and toasty with my Wabasto and treated fuel last winter. I was up at Zion, IL and I was ready to do what needed to be done, but it survived the night just fine and started no problem since the bunk heater circulates coolant, and the truck is arctic speced for insulation of the sleeper.

 

What kind of truck, and which Webasto is it? That's pretty impressive.

 

Company spec International LT from the NE. I've noticed it uses reflective insulation around the sleeper along with the regular stuff, and quilted sleeper curtains. There's also a fuel heater for the engine in the webasto fuel/water separator.

 

Not sure which model, but I have used bunk heater only into the -30s and occasionally to -40. No APU, but trucks (ProStar, 73" hi-rise) also had Webasto/Espar coolant heater.