RedHouse – System Test 2

The RedHouse is online!

We’ve got plants, we’ve got greenhouse and we are connected.  Using the particle photon and some very simple code, I can monitor the status of the redhouse from anywhere with internet connection.  I’ve been testing it for the past week and it’s been working well.  The biggest problem is unreliable wifi in the greenhouse, but that isn’t a killer problem.  I was still able to turn on the watering system while I was on vacation for a couple days.

There is still a lot of work to do, but we are far enough along to grow some serious plants.

 

Update (Sept 23): Wifi problem solved in software.  Connection is great now.  I added a huge external antenna, but it’s completely unnecessary.

Redhouse – System Test 1

I may have built up my own excitement, but the redhouse (geo-thermal “smart” greenhouse) is really coming together.  In theory, I can put my overgrown bathtub tomato plants tomorrow.  This makes me extremely excited.  On to the test.

This test will see if the pump, the piping in the beds and the irrigation system all work.  These are the questions this test was hopefully going to answer:

  • Will the pump have enough pressure to water both beds?
  • Will the holes drilled in the irrigation PVC spray acceptable water?
  • Are there water leaks?
  • How much can I water with a 7 gallon reservoir?

Most of the answers can be found in this video:

The short version of the test is:

  • Enough pressure? Yes
  • Holes? Acceptable
  • Leaks?  Yes.  Around the valves and in the pump box
  • 7 gallon enough?  Maybe not.

The reservoir is the biggest disappointment.  I quickly ran out of water in the 7 gallon barrel during this test.  Further, it fills up slower from the rain water store than I can put into the soil beds.  This will likely limit my watering to only a couple minutes at a time.  I will also have to be careful not to run out of rainwater.  If I need 14 gallons per day of water, I’ll only have 7 days in the store (two 55 gallon tanks).  It is possible to use my brothers two barrels.  That will give me a couple weeks and worse case I can fill up the tanks with house water.

Next test should be hooking up the controller.  We should be able to start getting some measurements to see the benefits of the geothermal system.

Redhouse (previously “geohouse”) – Construction

Over the past few weeks a lot of progress has been made on the redhouse.  First, the name of the project changed.  As we got the frame built, my son who is 8 started calling it the “redhouse” instead of greenhouse because of the red burgundy paint we used.  I liked the name.

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After painting we built the arches that will act as the equivalent to a Mittleider t-frame.  The reason there is no “t” in the frame is because we are maximizing wood usage.  The outer bed will also act as the support wall for the greenhouse film.  The benefit is, I can fit two beds in the redhouse.  The drawback is, the plants will be very close to the wall.  After building each arch, we put the arches in the ground from 12-15″.  The ground we are working with has a slope.  To make the arch level, one side is more shallow in the ground than the other.

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Oregon is rainy, so instead of using dirt or worse: cement to secure the posts, we used 1/4″ and 3/4″ crushed rock to allow for more drainage.

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Once both arches were up, we painted and laid the 2×10 boards that will become the garden bed.

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We also painted and installed some 2×4″ boards at the top to support the pvc hoops.

Once that was done, I created a base for the inner-bed tubing.  I used a 36″ x 2.5″ 12 guage aluminum sheet as the base and used zip ties to secure the tubing to the base.  Over the tubes in strategic location I put thin sheets of aluminum that are typically used with pex for radiant heating applications.

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Under the aluminum and tubes I put a sheet of reflective insulation.  I probably could have gone thicker, but this is okay for now.

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I put two holes in the board and attached braided tube for the inlet and outlet.  PEX tubing is not UV protected.  So I don’t want it exposed to the sun.  It’s also not very flexible.  So the braided tubing is great for in between the pex, the pump and the earth.

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Now that the inner tubes are installed and in place, time for the soil.  Following the Mittleider pattern, I’m using bark dust.  Normally the Mittleider system calls for traditional sawdust.  This fine dark hemlock dust, however, looks great and looks could help with heat absorption because of the dark color.  I mixed with about 30% sand and dumped it in the bed.

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For this 12 ft x 18″ bed, I used 400lbs of dust and close to half a cubic yard of hemlock dust.

Irrigation plumbing time.  Nearly following the Mittleider system by the book, I got thin wall 3/4″ pvc and drilled tiny boles in it for water to come out.  I also installed some ball valves so I can adjust the pressure and also close off the second bed if needed.  A bit about the second bed.  I’m assuming for the moment that I will not be able to heat/cool the second bed.  I’m being conservative.  If the first bed’s temperature is easy to maintain, I will add the second bed to the system next season.

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The redhouse.is coming together nicely.  Once I test the irrigation system and install the controller, I’ll transplant some bathroom tomatoes that are getting too big for the bathtub.  The only thing left after that is to attach the greenhouse film.

 

 

 

Geohouse – Heat pump and irrigation system explained

Here’s an explanation on how the pumping system will handle both the irrigation and the heat exchanging through the geo exchange.  It involves two relay-controlled valves: one normally open for the geo exchanger and one normally closed.  They will be hooked up to the same relay so that when the open one is closed, the closed valve will open and water will immediately be pumped into the irrigation pipes to water the plants.

This allows me to use the same water, water which is being temperature regulated, and the same pump for both irrigation and regulating the soil and air temperature.

 

 

Using yocto combo layers and adding a new layer

It’s easy to add your own layer using the combo layer system.

  1. Edit conf/combo-layers.conf and add a section for your layer.
  2. cp conf/combo-layers-local-sample.conf to conf/combo-layers-local.conf and add a section for your new layer
  3. run scripts/combo-layer init
  4. after you have a build directory (by sourcing oe-init-build-env) edit build/conf/bblayers.conf and add your layer
  5. bitbake as per normal