(The first winter trip consisted of 19 days/18 nights in Montana and Idaho during December, 2016. The overnight temperatures were consistently in the -20's C, while day time temperatures averaged around -10 with a few days around 0. So what worked and what didn't?
First, the basics:
19 days/18 nights
4400 km / 2800 miles
13.3 l/100km / 17.7 mpg
120 l / 32 gal. water
23 pounds propane
-33 C / -27 F minimum outdoor temperature
3 heater malfunctions
2 pee bottle incidents (self explanatory)
2 car malfunctions (fuel reader and stuck transmission - both due to cold, both fixed themselves)
1 stuck van
First, the basics:
19 days/18 nights
4400 km / 2800 miles
13.3 l/100km / 17.7 mpg
120 l / 32 gal. water
23 pounds propane
-33 C / -27 F minimum outdoor temperature
3 heater malfunctions
2 pee bottle incidents (self explanatory)
2 car malfunctions (fuel reader and stuck transmission - both due to cold, both fixed themselves)
1 stuck van
Heating - Qualified Success
We made it 17.5 days on the single 20 lb. container of propane, which given the low temperatures was much better than expected. However, we did cheat a bit. Because the forecast was very cold prior to the trip, we picked up a Mr. Heater 4-9000 BTU radiant heater as backup. This was also due to tests that showed that although the Propex heater would hold a reasonable temperature in the van, it would not heat it up quickly. We like to keep the van cold (just above freezing) when we are away. However, when we get back at the end of the day it is nice to be able to heat it up quickly, so more output than the Propex can supply is needed briefly.
We ended up using three one-pound propane containers on the Mr. Heater, or around 9 hours of heating on high. This was well worth it since we didn't have to worry about sitting around shivering after a day of skiing. The lower, more sustained output on the Propex was also ideal for drying mitts and boots!
We also had fun with error signals from the Propex:
7 flashes: overheat error - we managed to restrict the output flow from the heater so much while drying gloves that the heater went on error and one of our boot drying tubes partially melted!
5 flashes: plugged combustion air inlet/outlet - while driving blowing snow would get into the ends of the tubes meant to provide and vent combustion air. A few taps on the end of the pipe usually fixed this. Once the inlet had some snow in it so I had to lie in the snow and reach underneath the van to clear it.
2 flashes: out of propane! - just after midnight on the last night we noticed that it was getting rather cool and saw the telltale amber flashes from the Propex thermostat. This should have come as no surprise - I'm actually surprised it lasted that long.
We ended up using three one-pound propane containers on the Mr. Heater, or around 9 hours of heating on high. This was well worth it since we didn't have to worry about sitting around shivering after a day of skiing. The lower, more sustained output on the Propex was also ideal for drying mitts and boots!
We also had fun with error signals from the Propex:
7 flashes: overheat error - we managed to restrict the output flow from the heater so much while drying gloves that the heater went on error and one of our boot drying tubes partially melted!
5 flashes: plugged combustion air inlet/outlet - while driving blowing snow would get into the ends of the tubes meant to provide and vent combustion air. A few taps on the end of the pipe usually fixed this. Once the inlet had some snow in it so I had to lie in the snow and reach underneath the van to clear it.
2 flashes: out of propane! - just after midnight on the last night we noticed that it was getting rather cool and saw the telltale amber flashes from the Propex thermostat. This should have come as no surprise - I'm actually surprised it lasted that long.
Ventilation - Failure
Too much water vapour! Although the air exchanger did an admirable job (based on the amount of water that would drip out of it) it could not keep up with the amount of moisture put out by respiration, cooking, occasional 'showers', and the use of the radiant heater.
In addition to this, it was more difficult than expected to keep the air mixed in the van. The floor was usually 10 or more degrees or more below the ceiling temperature, highlighting the lack of air movement. Moisture from us while sleeping had a tendency to end up freezing at the bottom of the back doors, while moisture elsewhere froze around the edge of the woefully sealed side door, as well as any screw that happened to go into the metal frame of the van. In a disturbing trend, frost started appearing on certain sections of wood paneling, likely due to thermal bridging in the van insulation behind these areas!
To top it all off, the Maxx fan that we love so much in summer took on so much condensation and melting snow the few times it was used it decided to stop functioning. Apparently the exposed circuit board was not built for near submersion. This left us with just the air exchanger to move air (apart from opening a door, brrrrr.).
We have three take-aways from all of this. The first is that the ceiling fan needs a new speed controller, preferably placed far away from it to avoid water damage! As well, the air-exchanger needs to be able to handle more air than it was initially meant for. To do this I plan to increase the size of the coreplast heat exchanger core. This should allow the existing fans to push more air through. I also plan to embed the fans in the exchanger, rather than have them at the inlet and outlet. This should reduce the noise level and hopefully make it more pleasant to run it at higher levels at all times. The last item is that a fan needs to be running at most times in order to move warm air to the cold corners of the van. Even in the small volume of the van there is not enough air mixing going on naturally.
I should add that the amount of frost buildup around the sliding door is the result of the horrid seal that the stock van has. I plan to declare war on the door, and improve the seal by any means necessary.
In addition to this, it was more difficult than expected to keep the air mixed in the van. The floor was usually 10 or more degrees or more below the ceiling temperature, highlighting the lack of air movement. Moisture from us while sleeping had a tendency to end up freezing at the bottom of the back doors, while moisture elsewhere froze around the edge of the woefully sealed side door, as well as any screw that happened to go into the metal frame of the van. In a disturbing trend, frost started appearing on certain sections of wood paneling, likely due to thermal bridging in the van insulation behind these areas!
To top it all off, the Maxx fan that we love so much in summer took on so much condensation and melting snow the few times it was used it decided to stop functioning. Apparently the exposed circuit board was not built for near submersion. This left us with just the air exchanger to move air (apart from opening a door, brrrrr.).
We have three take-aways from all of this. The first is that the ceiling fan needs a new speed controller, preferably placed far away from it to avoid water damage! As well, the air-exchanger needs to be able to handle more air than it was initially meant for. To do this I plan to increase the size of the coreplast heat exchanger core. This should allow the existing fans to push more air through. I also plan to embed the fans in the exchanger, rather than have them at the inlet and outlet. This should reduce the noise level and hopefully make it more pleasant to run it at higher levels at all times. The last item is that a fan needs to be running at most times in order to move warm air to the cold corners of the van. Even in the small volume of the van there is not enough air mixing going on naturally.
I should add that the amount of frost buildup around the sliding door is the result of the horrid seal that the stock van has. I plan to declare war on the door, and improve the seal by any means necessary.
Water - Success (after measures taken)
This issue caught us by surprise, but makes sense in the light of the air stagnation mentioned above. We typically sleep with the van quite cool, usually below 10C/50F. This results in the floor being below zero, especially when the air outside goes full arctic.
And on the floor is our wonderfully baby whale footpump. The phase behaviour of water resulted in us having a frozen pump and water lines the first morning. After much wrangling and strategic heater placement we managed to thaw it out and get water moving.
The second time this happened to us we figured on a solution. At the end of the day we would pull the hose from the water jug, pump until the lines were mostly dry, and then use our kite pump to blow any residual water out of the lines. It was a bit of a pain but only took a minute or so and was much easier than thawing frozen lines. As a second measure, I got in the habit of overfilling the kettle when we boiled water and poured the left-overs into the water jug to limit the chance of the whole thing freezing.
And on the floor is our wonderfully baby whale footpump. The phase behaviour of water resulted in us having a frozen pump and water lines the first morning. After much wrangling and strategic heater placement we managed to thaw it out and get water moving.
The second time this happened to us we figured on a solution. At the end of the day we would pull the hose from the water jug, pump until the lines were mostly dry, and then use our kite pump to blow any residual water out of the lines. It was a bit of a pain but only took a minute or so and was much easier than thawing frozen lines. As a second measure, I got in the habit of overfilling the kettle when we boiled water and poured the left-overs into the water jug to limit the chance of the whole thing freezing.
Electricity (Failure)
As the designer of the electrical system the blame falls on me for this one. I made two bad assumptions: Firstly, that a system that lasted three days would be adequate for our needs, and secondly that the alternator would easily charge the batteries during travel days.
As it turned out, we didn't want to leave our first destination after three days. This made things somewhat awkward since the batteries were spent. We ended up staying and discharging the batteries below the ideal 50% state (but running the van for an hour to help assuage our guilt). The problem is...
The alternator charges the batteries slowly! I expected a fast charge (I don't know what I based this on, maybe just because the van has a 220 amp alternator?). To support this I had connected the house batteries to the car batteries with an 80 amp breaker! So with the engine running and a pair of flat batteries I flipped the leads on the ammeter shunt and saw a total flow of 5 AMPS! At his rate it would take 20 hours to charge the batteries back to 100%, and that doesn't even take into account the 75% efficiency of charging lead acid batteries, or the lower rate of charge as the batteries reach full charge.
This was confirmed when a two hour drive fed a measly 240 W to the batteries, better than 5 amps, but still way to low to charge the batteries fully in a days drive.
Ultimately we are going to need to add battery capacity and/or solar/generator/fast charging (if the car alternator will support it). For now, we are good for long weekends so the pressure is off until the next vacation.
As it turned out, we didn't want to leave our first destination after three days. This made things somewhat awkward since the batteries were spent. We ended up staying and discharging the batteries below the ideal 50% state (but running the van for an hour to help assuage our guilt). The problem is...
The alternator charges the batteries slowly! I expected a fast charge (I don't know what I based this on, maybe just because the van has a 220 amp alternator?). To support this I had connected the house batteries to the car batteries with an 80 amp breaker! So with the engine running and a pair of flat batteries I flipped the leads on the ammeter shunt and saw a total flow of 5 AMPS! At his rate it would take 20 hours to charge the batteries back to 100%, and that doesn't even take into account the 75% efficiency of charging lead acid batteries, or the lower rate of charge as the batteries reach full charge.
This was confirmed when a two hour drive fed a measly 240 W to the batteries, better than 5 amps, but still way to low to charge the batteries fully in a days drive.
Ultimately we are going to need to add battery capacity and/or solar/generator/fast charging (if the car alternator will support it). For now, we are good for long weekends so the pressure is off until the next vacation.