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Solar oven project update

Posted by admin on Sep 29th, 2008
Sep 29

I started cutting out the frame of the new solar oven from scrap plywood laying around in the garage this past weekend. I have all of the sides cut out and ready for assembly, I just need to find my wood dowel pins to put the pieces together and I need to find a scrap piece of wood big enough for the bottom. I had to make the sides in two pieces because I didn’t have anything left that was big enough to make it solid. Here’s what I have so far:

The top of the sides are set at a 30 degree angle – I had read that is the optimal angle for solar panels somewhere. Once I locate my dowel pins and find a piece for the bottom then it should go together fairly quickly.

Here’s a picture of the one I built last summer. It’s got an old window I found in our garage from some previous owner, and it works pretty well. It’s lined with foil and the bricks in the bottom are to help keep the temperature a little more even. The test I did with it yesterday got it up to over 170 degrees. If it was built a little better and all the gaps and holes sealed up then I might be able to get it hot enough to boil water. I’ll be adding reflector flaps to the new one to ensure it will get more than hot enough for that. It currently sits on an old skateboard for portability, because with the bricks it’s quite heavy:

Does window efficiency film work?

Posted by admin on Sep 29th, 2008
Sep 29

About two weeks ago I wrote that I was going to try to make our single paned windows in our home more energy efficient by using a window film that claims to block around 70% of the suns radiant heat. This weekend I finally completed enough of the project to get an idea on if I’m heading in the right direction. It seems that I might just have wasted my time and money on this.

Of the 12 “panes” on the window, I put the film on 11 of them. I left the top middle pane untouched so I could test the difference in temperature between the filmed and non-filmed sections. I went to Harbor Freight to pick up a cheap infra-red thermometer ($10 – and I plan to use it around the house to find hot and cold spots). Since it was doing the testing on glass, I wanted to make sure it wasn’t skewing the test results when I checked the window temperature so I first put a large washer on the two test panes (the top left pane and the top middle pane) and checked the temp. Hmm – 106 degrees for the non-filmed pane, and 104 degrees for the filmed pane. Whoa.

Okay, maybe the metal washer is making a difference. I decided to put a paper mailing label on each window – that way I would have a surface to test that wouldn’t potentially accumulate heat due to the material it is made from. It did make a difference, the temperatures dropped about 5 degrees for each pane, but they were still 2 degrees apart. The filmed pane was 99.3 degrees and the non-filmed was 101.3.

That’s very disappointing. I’m going to double check the directions, and look for some tips online from others who may have tried the film and see if they have any suggestions on what the problem might be. If I can’t find that I’ve done something wrong then I’ll start looking for alternate ideas to make the windows more efficient.

Sep 25

My wife, of course, likes to take baths. My son is afraid of the shower so he takes baths. I try to conserve water wherever I can and even take a 5 Gallon Bucket into the shower with me to collect the water when it’s heating up, and while I’m lathering up (5th paragraph down in the post). In a way I am a bit hypocritical in the sense that I have a pool, and pools aren’t eco-friendly or promote water conservation. I’ve been trying to think of ways to offset the extra consumption of water due to the pool – which leads me back to the bath water.

Our entire yard was cemented over a long time ago. It’s both a blessing and a curse in that it’s nice to not have to mow a lawn or do extra yard work and we save a lot of water by not having grass or other plant life, but it retains heat in a horrible way and on extremely hot days it may not cool down until 2am. It’s essentially a “hose down” yard but if it gets hosed down a few times a week then we aren’t saving any water over a grassed yard. We have two large dogs, so it needs to be hosed down often. I have been looking for a way to clean the bath water well enough to be able to use it to hose down the yard – thus re-purposing a large amount of used water.

I bought a 5.5GPM pump a while back from a used electronics store and I have lots of marine batteries to hook it up to. I also have three 55 gallon barrels which I can pump the water into. I wanted to build something to filter the water before it made it into the barrel, because it’s easier at that point that to filter it while it’s being siphoned out for use. Here’s what I came up with – which was inspired by an episode of Renovation Nation where a homeowner built something similar to filter rainwater:

  • 5 gallon bucket – can be bought at a hardware store for under $5, but most people already have one laying around

  • a 1 1/2″ pipe connector – male and female – for the drain hole. About $4 from the hardware store

  • two 2″ rubber gaskets for the pipe connectors, to seal around the hole. About $2.50 for a two pack (check in the faucet repair area in the plumbing section)

  • bag of sand – it was harder to find than I thought. About $4.50. This will do the core of the filtration

  • bag of pea gravel – about $3.50. This is used to keep the outlet from getting clogged up and to level out the bottom of the inside of the filter

  • Koi pond filter – also found at the hardware store in the outdoor garden center by the pond equipment. It was the most expensive piece @ $10. This is used to keep the sand in the filter, and also does some large particle filtering – hair and whatnot

  • Optional – a pack of terry cloths, about $2.50. I used them mainly for additional protection from the sand coming out and also to prevent the Koi pond filters from getting clogged up with sand.

Here are the step-by-step pictures of the project as I constructed the filter. You’ll notice that I had already cut the hole and put the pipe fitting in the bucket at this point. Also, before the pipe fitting is installed you’ll need to drill a few holes in the top pipe fitting (the piece that is in the bucket when assembled, not sticking out of the bottom) for complete drainage.

The parts list

Wash the pea gravel to get all the dirt off and fill the bottom of the bucket with enough pea gravel to make it level with the top of the pipe connector (the one that you drilled holes into before assembling)

I put a terry cloth rag on top of the gravel, in an attempt to make cleanup easier later

The Koi pond filter comes in two pieces, the denser one goes in at this point (it’s like a scrubber pad). These should have been cut to fit the bucket, but I was impatient and wanted to try it out

I put another terry cloth on top of that – this is important to help keep the sand out of the filter as much as possible

Put about 4″ of sand on top and level it out

Then another terry cloth, if you want to

Then the other half of the Koi pond filter

Then I threw on another terry cloth on top of all that. Now it’s time for the test. It’s best if you let clean water run through it for a few minutes to clean out all the dirt that needs to be washed out of the filter initially. It’s like a carbon filter for your refrigerator that also needs to have water run through it before it can be used. In hindsight I should have washed the pebbles before putting them in the filter, but it’s a lesson learned. Here’s my initial test run. The pipe fitting fits perfectly into the opening on the barrel it’s sitting on in the picture:

I suppose a disclaimer is in order. This filter is for NON-potable water only! Do not drink it.

Motorcycle hypermiling, and solar oven part II

Posted by admin on Sep 19th, 2008
Sep 19

Since becoming a new motorcycle rider over the last two months I’ve had to put my hypermiling “research” on hold. I needed to fully focus my attention on what I was doing while riding because looking at the pavement pass by and thinking that if I make one little mistake…and the pavement up ahead could be permanently embedded in various parts of my body. Now that I’ve got over 800 miles under my belt on the bike I’m feeling much more comfortable and have actually started incorporating a few of the techniques I learned while hypermiling in the car. The hard part though, is that since it’s a manual transmission and I don’t always know what gear I’m in, it’s a bit dangerous to put it back into gear in certain situations (like turns, for example) so I don’t coast as much as I could otherwise.

This weekend I’m planning to find as much scrap wood around the house and rebuild my solar oven. My initial attempt turned out alright, and we cooked some beans in it one day (I think it took 6 hours tho), but it’s not sealed very well and should be made deeper and more efficient. So, as promissed in one of my early on posts, I’m going to rebuild it and document it for those who might want to attempt the same project.

Making our windows more efficient, part 2

Posted by admin on Sep 15th, 2008
Sep 15

As promissed, here is the update to the window insulation film project. I decided to go with the Artscape’s Energy Film Window Film because there was no adhesive required. I thought it was going to be a simple “stick it on the window and forget it” type of a deal, but I was mistaken. It turned out to be more involved than I thought.

The biggest problem was that the package didn’t have any installation instructions, I had to go to the Artscape website and click on the “Installation” tab at the top of the screen. That’s where I found out that I needed a soapy water solution sprayed on the window and the film for it to adhere to the window.

Our windows have a faux window pane effect – i.e. they have these vinyl strips glued to the window to look like individual panes. I would love to take those pieces off but it would probably damage the window or leave a residue from the glue. Unfortunately, this means I have to cut out 12 12″x9″ pieces of the film per window. I’ve never really liked that style of window, but as much as I dislike them we’re going to have to live with them for a while, otherwise I wouldn’t have to be going through this effort.

Because of all of the individual pieces I needed to cut out and the extra time involved I was only able put up a test piece on one section. According to the instructions, the window can’t be hot when it is applied so I had to wait until the evening. The next day I did a hand test and found that the part of the window with the film on it was at least 20 degrees cooler than the unprotected “pane”. I’m going to finish the installation this week and then do some temperature checks to get a more accurate figure of the temperature difference between the filmed and unfilmed windows.

Build your own bike?

Posted by admin on Sep 12th, 2008
Sep 12

I know there are far more eco-friendly ways to make your own transportation, but I couldn’t help but post about this site – Atomic Zombie – that sells plans to make your own custom bikes. Basically, you’ll need some welding skills and a few tools, but some of these bikes are insane!

If you don’t know how to weld, then here’s an Instructable to teach you how using golf cart batteries. And if you have solar panels to charge your batteries then it’s even fairly eco! I might just have to try this – after I finish my honey-do’s, rebuilding my solar oven, putting heat blocking window films on the windows, insulating the exterior walls, etc…

Making our windows more efficient

Posted by admin on Sep 9th, 2008
Sep 9

If you’re a regular reader here at EcoExist, you are familiar with the various things I’ve been up to in order to make our home more efficient. Living in the San Fernando valley it gets quite hot in the summer time, so because of this most of my focus has been on making our house stay as cool as possible without turning on the AC. It usually hits about 89 at around 4:00pm inside the house so obviously we do need the AC at that point. Up to about 85 is bearable now that we’ve become somewhat used to it, but there is a limit!

The main problem that causes the house to get so hot is that the windows are single pane, and that the exterior walls aren’t insulated – which is on my project list. We may as well just leave all the windows and doors open with how well our house is insulated. Why these things weren’t addressed in the 56 years since the house was built is beyond me. I guess the former owners didn’t mind using tons of electricity to power the AC. The funny thing is that the house was remodelled and the windows had been replaced at some point. Single pane? Seriously? Sheesh.

The only thing that is adequitely insulated is the attic, but that’s only because we blew in insulation up there earlier this year, which didn’t make as much of a difference as I had hoped. I’ve been researching several ways to try to maintain a more consistant and comfortable temperature inside the house without using any additional electricity and without spending a lot of money. One thing I’m considering is putting in a skylight that is designed to open and act like a solar chimney, which would allow the hot air to escape and pull in the cooler air at night. This of course would require a considerable amount of construction time. It’s still on my list but is pushed out farther. The other thing I had been considering is replacing the windows myself – but I’ve never installed a window before and we just had our house painted a few months ago so the idea of doing that is definitely postponed until later.

The best idea I’ve found so far is to use an insulating or tinted film on the windows. I had previously thought that the lack of insulation in the walls was the main culprit for how hot the house gets, but after doing some checks with my hand on various walls, and then on the windows, I found that the walls are the least of the issue and that the windows get really hot in the afternoon, almost too hot to touch. My son’s room was always the hottest which makes perfect sense since his room has the biggest window in the house and faces West for the afternoon and evening sun. This weekend I’m going to go to my local hardware store and see what I can find to try out. I’ve done some preliminary investigation and have narrowed it down to either Artscape’s Energy Film Window Film or Gila’s Titanium Heat Control Window Film. The Artscape is apparently like a cling on film, while the Gila needs to be glued on.

I’ll update with which one I chose and how well it works this weekend!