Saturday, November 22, 2008

Conversion Photo Journal 4

Chapter 4: Interior work, lighting design, and insulation.

November has been a slow month for the van. After the floor was installed I moved on to the walls which posed some new challenges. The walls need to be framed, insulated and paneled. However, there is not much to attach things to and very few even surfaces that I can use. Real houses are easier because everything is flat and box shaped. With the van I've got to figure out how to fit flat wood around all sorts of curved surfaces and how to insulate all kinds of small, strangely shaped crevases. The classic square peg in a round hole problem. The framing is important because I'll be anchoring stuff like my bed, heater, and kitchen counter to it. It needs to be solid and bombproof so that crap doesn't get pulled off the walls and get wrecked if I hit a speed bump.

My solution: procrastination. I'm not sure how to go about it and since it is going to be a foundation for everything else to come, I don't want to screw it up.

So instead of starting on the walls, I started on some of the smaller manageable projects that I could move into the van after I frame it and get the walls done.

I got these solid maple cabinet doors for like 3 dollars at the habitat for humanity restore! Solid maple! They were painted an ugly translucent white and had some scratches but I knew that if they were sanded and refinished they would be beautiful. So I did that.

I couldn't sand off the paint that was inside of the route, so I looked around the garage for something to cover up that ugly pastel white.I found some glossy green spray paint that matched my countertop perfectly. So I taped off everything but the routed area and painted them.
I put them infront of the counter to get an idea of what it would look like when finished. pretty.
I made the moulding around the edges of the countertop with some old wood I found in the garage, and a makeshift [read: ghetto ass] router. Not perfect but it has a cool handcarved look. I've since added a light coat of stain to all of the bare wood and finished everything with two coats of polyurithane. It looks really pretty, I'll get some pictures when it is installed in the van.

Hightech vandwelling.
If you haven't experienced my nerdiness you are about to get a full dose. I love LEDs (light emitting diodes). They are more efficient than compact florescents and incandecent lights, and they never burn out (lifespan >50,000 hours). If you have money to invest, invest it in LEDs. High power LED technology is growing very fast and every time I get a new electronic parts catalog the LED section has new pages. Mark my words, in 20 years LED and solid state lighting technology will be the primary source of artificial lighting in homes. It is the future in sustainable lighting.

Even if you don't know what LEDs are, you've seen them everywhere. New traffic lights, toys, flashlights, car dashboards...the list could go on and on. Beyond those cheap little clear bulbs there is a new type of LED technology emerging capable of producing almost 100 lumens per watt. LEDs that can do this are called "high-flux" LEDs... and I'm putting these in my van.

The cool thing about LEDs is they produce almost no heat and because they are solid state they can be switched on and off repeatedly with no reduction in lifespan. However, since LEDs are either on or off, you can't dim them efficiently unless you get creative. So I decided to use the switching capabilities to my advantage. I added a simple PWM (pulse width modulation) circuit into the LED driver to pulse the LEDs off and on at about 300Hz. That is fairly slow in the electronics world but fast enough not to be detectable by the human eye. I can then modulate the wave to change the length of time that the LEDs are on or off. Here is the schematic I drew of my system.

I took some pictures with an oscilloscope to help illustrate the PWM concept.

The dots on the top are the "ON" time, while the line at the bottom is the "OFF" time. In this picture, the PWM is running a 5% duty cycle which means it is only ON 5% of the time.
Here it is again, this time at about 20%.
So, I definitely took the not so simple approach with lighting but I'll save a lot of power to use for other things.
Lastly, I've started insulating what I can. Here I'm filling up the door cavity with the styrofoam board that my solar panels were packaged in. I just stacked it in there like bricks. I sort of felt like an Eskimo cutting and stacking blocks of white stuff to keep me warm.