Author Topic: Truck 2 years old today...  (Read 2310 times)

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Offline MadScientist267

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Truck 2 years old today...
« on: January 15, 2018, 02:10:22 pm »
Well today is the truck's official second birthday, and there's a lot to be said... But I think I'll just start out with why...

It's also the line in the sand where all of this was originally supposed to end.

The idea with 2 years was simple; It would allow, one way or the other, the viability of this to be proven. 1 year would have meant plausible, 2 is undeniable, regardless of outcome.

It isn't over exactly, in the sense that things will be status quo for a while longer, but having now reached this line, I can officially declare it's status.

I'm going to go with "technologically a success, but a bit of a reach for practical".

I've learned a great many things in the course of conceiving, building, living in, modifying, and otherwise making it become what it is as of this moment... Not only about all the physics and what it takes to battle nature's offerings, but also about myself and what some of my more notable limits are, among other things.

It's been a lot of fun, and a lot of work, both, and demonstrates that it's possible to do something like this, even tho it falls short on a few levels. There's a strange relationship between us, having been a direct brainfart of my own creation. In a lot of abstract ways, it's become my best friend. Likewise, and just as importantly, an arch nemesis. And everything in between. It has a personality, for sure, and being somewhat computer controlled... even thinks like me.

So what are some of the things I've discovered on this adventure?

The hardest part by far, generally speaking, would be energy management. This is largely due to the lack of abundant rooftop real estate on something this size. At around 136 sqft, there's not a whole lot to be had, and at times, it can get spread pretty thin. There's 800W (label) worth of PV up there, and after losses and age of the panels (they were used when I got them), I typically see a peak around the 600W mark on an "ideal day". There was also never any plan to do any thermal up there, for a couple reasons, but the main one being that there simply wasn't any room.

A lot of the energy that gets made is spent on managing the inside environment thermally... Fans in both winter and summer, just for starters. Moving air takes a surprising amount of energy, even when done efficiently. This is largely because it adds up; they can be considered part of the base load because they run just about full time toward and during the extremes of the seasons.

Later on, I also added a small air conditioner, as well as some "wax stabilized" resistive heating. In summer, there is plenty of power available, until the air comes into play; the PV can barely break even with it for just a few hours a day near solstice. This was known prior to the build, and as such, was ruled out as even a possibility, until I discovered a relatively efficient 5k window unit. It largely finds use in managing humidity when I'm running on pure PV. Even the genset can't really sustain it very well due to its age, but does get used to assist the PV to help make things comfortable.

And while the (electric) heater isn't much more than trivial (~36W max, it's very targeted), it too strains the system in winter because the light is so short.

The main heat source is a heavily modified catalytic propane heater that's designed to trap as much of its infrared for its own use as possible, and convert the resultant output into convection. The primary reason for this was for efficiency and to facilitate clean combustion with a much lower gas flow to the catalyst. Basically, it reflects a lot of the IR back at the catalyst, causing it to run hotter for a given input, allowing the valve to be closed much further, without producing monoxide. Don't try this at home :)

Spring is by far the easiest, as the temperatures are modest, and light becomes more and more plentiful. This is the only time of year that could be considered to have a "surplus" of energy if there really is a such thing. Running the laptop for extended periods on a sunny day at this point becomes much easier, and productivity in general goes up significantly.

Late summer into early fall is the hardest because the sun starts to fall into the trees, which still have leaves on them at that point. Cooling is much more energy intensive than heating is, so the system in general struggles to make ends meet this time of year.

Refrigeration is possible for the majority of the year, albeit a little less controlled in the winter due to the shorter light supply. I use the outside a fair amount to make up the difference, but of course I have to be diligent with perishables because of temp fluctuations. In the summer, because of limitations in the overall design, the fridge also creates a lot of extra heat that I have to get rid of in some way. In the cooler months with more adequate light, this works in my favor, but in summer, can make things very uncomfortable.

There is a microwave for cooking food, although it had to be an "inverter" type, to limit the amount of current the batteries needed to supply. I normally only run it at power level 3, which works out to about 600W of input. It's a little slower than full throttle of course, but can get there in a reasonable time, so it works.

There is no running water, for a multitude of reasons, but the biggest two are that A, there isn't really room to have all of the things I wanted to do, and have everything that water would have required. B is simple as well, I didn't want to deal with all the issues and implications that having it on board would have meant. This does of course complicate things, but since it was decided from the beginning that there would be none, other provisions were made to deal with some aspects. The others got refined as time went on. In a nutshell, a Y membership covers the showers etc, and a couple of systems for handling waste came to be. In all, again, not necessarily the most practical, but doable with minimal fuss, and more importantly, safe.

Storage also has proven to be an issue, but then again, when is it not... lol

The sleeping arrangement is set up for seasonal, with a murphy style bed for summer that folds down to right at the floor line underneath the "ceiling fan", with the "attic" being used for storage. In winter, the bed goes up against the wall, and the space in front of it used for storage, and the mattress gets moved to the attic. This allows me to curtain off a small space, up high, and trap heat efficiently. It is also where the above mentioned resistive heat is; imagine a "crock pot sized electric dog" at the foot of the bed... :)

Ventilation was also a tricky thing given all of the concepts that had to be considered both originally and as time went on. I planned in the beginning for a much more stealth approach to the whole design, to facilitate the original travel plans. This didn't work out for a number of reasons, but one of them was because of the needs that thermal management posed. The system originally was only going to use two 4" tubes, one intake, one exhaust. In winter this may have even been possible, had it not been for getting spooked by a freeze that bound the big door up (ok down, actually lol), and in summer, I have to move a LOT more air. So the back stays open when I'm stationary. So much for stealth.

That said, due to other limitations such as ability to fabricate and modify various aspects to make changes, I had to get whimsical to turn it into something that could handle all the seasons. What it comes down to is a bidirectional system that pulls air in along the floor and exhausts high in summer, and the opposite in winter. The winter mode is much more effective because it now exploits natural convection much more efficiently thanks to the increased inside/outside deltas. Fresh air is pulled in from the ceiling gap (from along the big door), which helps reduce heat loss thru the roof, and a complementary fan simultaneously pulls the cold air out at the floor line and exhausts it. The result is that the much cooler intake air gets mixed before it has a chance to fall naturally (by the ceiling fan, which does regulation duty in winter). The other drafts, along with the then cooled air from the rest of the room are sucked out before they can build a "hard layer" at the floor.

There are a couple of drawbacks to this design, but it was the best compromise I could come up with given what was at hand. The main drawbacks being that A, it doesn't always completely prevent condensation at the roof line (tho does drastically reduce it). And B, below a certain point, if the fans begin to throttle back too far to try and maintain the ceiling line temp, it can lose its "grip" and the cold layer can still form and build up.

The latter isn't always an actual drawback; it depends on what I'm trying to do. At night, it's pretty much inconsequential, and actually acts somewhat to increase the overall heating efficiency naturally (I don't need to increase the gas flow to maintain the ceiling line temps because the lower part of the box isn't losing as much heat thru delta conduction to the outside). During the day however, when feet are on the floor, this can obviously make for some uncomfortable conditions. Given what I had to work with tho, it works surprisingly well, all things considered.

There are countless other things that could be covered here, but I think I'll cap this particular post with quite possibly the most important aspect of all this...

It's been an interesting journey, and I don't regret doing any of it, although it certainly has had its moments. I would encourage anyone that's considered something like this to give it a shot and see what comes out of it, as one will learn all kinds of unexpected things in the process. It will test your understanding of just about every aspect of life, and will demonstrate both under and over estimations in what you thought you might be capable of (there are plenty of both to be had), and if you take it to some of the extremes I have, it'll put your physical, mental, spiritual, and every other "-al" you have to the ultimate test.

Which leads me to my last thought before I let this go out into the wild...

It's certainly rewarding to have set a goal of this size and seen it to completion in terms of intent and a date and such... But be warned, it's very stressful in the form I've done it in, and I've noticed a significant acceleration in my aging during this time frame. It would have been much better to do as a much younger being, but then again, I wouldn't have had a clue back then where to even begin, so it's a wash. Call it something of a life's dream of sorts, but it did come at a price.

I still don't regret it however, and my most sincere thanks goes out to all that have helped out along the way. There are so many of you, and in so many different ways, that I simply can't list everyone and everything without feeling like I'd leave someone out somehow. But you know who you are, and I do as well, and it wouldn't have been possible without you!

Steve

[PS... So *now* what... lol]
Wanted: Schrödinger's cat, dead and alive.

Offline bj

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Re: Truck 2 years old today...
« Reply #1 on: January 17, 2018, 06:28:12 am »
   Two years.  Times does fly.
   From the outside, looking in,  I would call it a wildly successful project.
   Difficult task at best, and you perservered, with many sucesses along the way.
   A few non-sucesses?  Maybe, but my take on that-- is that the only people that never
make mistakes are the ones that can't be bothered to try anything.
   
"Even a blind squirrel will find an acorn once in a while"
bj

Offline Pete

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Re: Truck 2 years old today...
« Reply #2 on: January 17, 2018, 02:23:16 pm »
Hi Steve, just wondering if you have considered putting solar panels on a wind out awning. It could fold down onto the side of the truck when driving and then be wound out when stopped. The panels on the roof would not always be at an optimum angle for power production, putting panels on an awning on the side would solve that issue plus give you much more power.
How about wind powered ventilators for summer?.
Anyway  sounds like you are having fun solving the problems as they arise. Good luck and happy travels
Pete

Offline MadScientist267

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Re: Truck 2 years old today...
« Reply #3 on: January 18, 2018, 02:40:16 am »
BJ -

Indeed it does... And imagine, that's just since launch... Tack on the other year and a half on the build... doesn't make it any "stickier" haha  :o

I certainly expected to make mistakes... there were only a handful of things that carried over from the van experiments that had been ironed out to the point I knew their upgraded counterparts would just work. The rest was very much a guessing game. I watched as closely as I could while mimicking the energy input, for example, because of so many things relying on so much else. In some ways it's even amazing it works as well as it does. Lots of heavy theory and blind faith involved after the short list of "solid known" ran out lol

Pete -

That's certainly one idea that's crossed the table over time. Several different things have been pondered as to how to increase output over time. Like just about every other aspect of this, there's always more to it than meets the eye. Even tho I couldn't keep with full stealth to protect it in the wild, I kept as many of those "features" as possible, to that end. Ultimately this took a few options away when it came to power, and extra panels hanging off the side was one of those. It's certainly an option technology-wise, just not so appetizing for certain locations.

Other things considered along those lines, that would have been a bit more robust, included things like reflective surfaces in various forms (namely flat white took the top of that list in some of the ponderings), and even an extension of that whole thing that would have left it looking something like an X wing fighter (thermal shielding + PV boost in summer)... All kinds of stuff got messed with on paper, none managed to make it further... Not even necessarily from being shot down. A lot of this stuff, I just don't have the resources to mess with now that it's all out there.

All that said tho, that's partly why I wanted to do some of this stuff. I wanted to be able to "give back the van" so to speak, to all of you... Meaning, "here's what I tried and what its strengths and weaknesses are known to be", so that someone could expand on them on various levels from here. Hoping to find out I'm not the only squirrely nut in the tree crazy enough to try this stuff ;D

Steve
Wanted: Schrödinger's cat, dead and alive.

Offline ZoNiE

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Re: Truck 2 years old today...
« Reply #4 on: March 19, 2018, 10:17:57 pm »
Wow, I watched your progress since the van.
SO, Yeah, Now what? Back to living in sticks and bricks?
Ever heard from the girl who signed her title over to you? Wonder if she ever made it.

Offline MadScientist267

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Re: Truck 2 years old today...
« Reply #5 on: April 13, 2018, 04:14:29 pm »
Apologies ZoNiE... lost in the shuffle there :/

Going on with it for the moment, but yeah, "done what I came to do" with this, and looking to go back to simpler times lol

Haven't had any contact from her... I keep a loose eye here and there just to keep curiosity satisfied. At last peek, she appeared to be doing fairly well for herself. Always good to see.

Steve
Wanted: Schrödinger's cat, dead and alive.