The Airtronic has a dedicated fan that runs off of 12V DC. Amps depend on BTU output (low, medium, high, or boost) as described in the manual you linked to. It’s a very low current draw and remember that the heater cycles on and off so it’s only a percentage of the rated amperage draw for a given period of time.
The level of heat output varies greatly depending on how well insulated your coach is. Guesstimating, for us anything above 35F is basically on the low setting once an inside temperature of 68F or above is established. Around 15F to 35F it’s medium and the depending on how windy it is, the off cycle time can be minimal. Zero to 15F is intermittent between high and medium if my memory serves me correctly. Again wind has a lot to do with cycle time at the low temps. We partition off the front area (windshield, side windows, and firewall) to help hold in the heat. It would have helped a lot if I had insulated the floor better.
My electrical needs are dominated by the efficient Engel fridge. So cold weather produces enough fridge savings to offset any Airtronic draw.
Of course, my foamed walls and ceiling and just three added windows are a great help for warmth and also resist the summer greenhouse effect.
I'm a little too tall at 6'4" to have added as much ceiling insulation (just to the ribs) as I would have liked. My project list includes removable foam/ply sections to add to the floor for the coldest weather. We also have quilt-and-mylar fabric ready to be made into insulating panels for the windows at night.
My next van conversion will probably use every square inch of underside for the batteries, a seasonal fresh water tank and lockable floor storage. I've seen winterized trailers that seal the bottom side with plastic or metal panels. I'd think hard about insulating there with something that could handle road spray or other moisture.
I love the removable propane, the lightweight aluminum structures, and the minimalist approach to fixed installation in my van. The rule of thumb in drag racing is that every 100 lbs will cost you a tenth of a second in the quarter-mile. Cars might lose about a mile per gallon for every 250 lbs. So the van has much better performance around town with the water minimized and ten storage containers left in the house.
Dan
02 Freightliner Sprinter 2500 long tall home brew conversion
I'm just starting on an Airtonic D2 install in my SMB Sprinter. I also want to protect the gray tanks and black and gray drain pipes (fresh water and black tanks are inside).
I thought about using the Hydronic heater instead but settled on the following approach. The main driver of this choice is that I'm not running any potentially leaky collant lines inside the van living space.
1. Airtronic D2 under van in splash box.
2.Insulated ducting under van
3.Heat exchanger to engine coolant loop that protects all the tanks and pipes - driven by small coolant tolerant pump - tanks and pipes insulated of course.
I considered electric tank/ pipe heaters but they would have consumed hundreds of $ and dozens of amps.
Also the Airtonic D2 Manual says no biodiesel (5% limit). The fuel line is 1.5mm dia. If it is really cold, you might need a winter mix diesel to get through the line.
You need a special adjustment to the fuel metering pump to do extended operation above 1500 Meters.
Offline
