Saturday, June 22, 2019

How to Build a Smart Greenhouse on the Cheap

This video is the culmination of about 4 years of research on the internet on how to build a smart greenhouse.    I share this information here so you don't have to spend all the time that I did  if you want to do so.  At the end of this video it talks about how to get an almost free greenhouse via a grant.

Watch on YouTube here.  I wish I knew where that stupid cricket was that you can hear in that video.  Pretty annoying.

About four years ago, when I knew we were moving to Midway, UT, I started researching how to setup a smart greenhouse for my giant pumpkin growing.  You've heard of smart homes, well, why not a smart greenhouse?   I knew the environment in Midway was going to tougher than Denver's.  We are at over 5,600 feet and the growing season is a whole month shorter than Denver's.  So I started researching how to deal with cool nights and hot days.  A greenhouse was the obvious solution and the new house in Midway has enough land for one.  But a greenhouse can't really control night time temperatures.  The thin plastic really provides no insulation.

So the first solution was to add 55 gallon water barrels painted black and filled with water.  Those black barrels absorb the sun's warmth during the day (85 degrees+ in the water) and then after sun down release that heat during the night.  So far, what I've found is that the greenhouse stays warmer then the outside air for a couple of hours, but not much more than that.

The next solution I came up with to help with the temperatures was a geo thermal system.  I dug out the pumpkin patch soil prior to moving into the house and put corrugated pipe winding back and forth through the whole patch about two feet down in the soil and then covered it.  On one corner of the greenhouse that soil pops up and is attached to an inline fan.  On the opposite corner that same pipe pops up and goes to the top of the greenhouse where it sucks the air in.  That hot air then warms the soil during the day, which can then be radiated into the greenhouse.  You have to be careful not to run it too long however, because I'm told you can burn up the roots.

The next solution was shared to me by Ralf Laub and was probably the 2nd best idea he gave me (the best idea saved me thousands of dollars and is shared at the end of the video).  Ralf lives in Vernal and has a very similar growing environment.  In his greenhouse he added one of those portable, camping hot water heaters for showers that he has connected to his irrigation.  That hot water heater warms the water and then is mixed with his regular irrigation water.   The combination of the warmed water and the exhaust from the hot water heater warms the greenhouse early in the morning just before sunrise.  These hot water heaters don't have enough volume (about 3-5 gallons per minute) to run an irrigation system, so that is why you have to mix two irrigation lines together.

For the heat of the day I put in indoor/outdoor fans (thanks mom for the Christmas present--best way to build a smart greenhouse on the cheap) that are controlled by an indoor/outdoor smart plug that can stand a little water.  This smart plug has an app that I can set multiple timers for and I can also manually turn on or off.  Earlier this spring I was in Canada.  I have a Acurite wireless temperature gauge that also has an app and will give me alert messages if the greenhouse gets to hot.  A couple of times I got alerts so I would go to my smart plug app and click the button for the fans and cooled things down fairly quickly.

Also for the heat of the day I added a fogger misting system in the roof of the greenhouse that uses Jain foggers.  It sprays a very fine mist into the air.  Just enough to cool but not so much that the moister stays on the leaves long, which is perfect).  It is controlled by a Rachio sprinkler controller that I love and controls all of the irrigation.   I got it and the state rebated something like $120 off for it because it can help save how much water you use on the lawn.  Rachio also has an app so I can manually run the water as I need from anywhere and set dozens of water schedules.  The downside to Rachio is it isn't cheap, but with the rebate it made it very worth it.

All of these devices have an API that allows you to write scripts (programming experience needed).  My plan is to write a script that automates intelligently the different pieces.  So for example, the fans will come on when it gets over 84 degrees, but turn off when it gets below 84.  But also, when the foggers turn on the fans will turn off for 1 minute and then turn back on.

Does all of this stuff work and is it worth the time and effort?  The honest answer to that is I think so, but time will tell.   Most of the stuff I talk about in the video has only been up and running for a week or less.  Circumstances and time have set me behind this year.  Originally I planned to have most all of this done back in April.  So I really lost the advantages of it to this point, so hopefully I can make up some of that lost time now.  I can tell you I've never had leaves look so good at this point of the season.

Is some of this stuff an unfair advantage?   Yes and no, but mostly no.  Even with all of this smart greenhouse stuff my growing environment isn't even close to someone that is growing in Ohio or Rhode Island outdoors.  Today is the 2nd day of summer and it was 37 degrees last night (greenhouse was just 6 degrees warmer with heat lamps and a space heater running, plus all of the rest of the stuff I mentioned).  Tonight is forecasted for 32 degrees (this isn't normal).   An average summer nighttime low in July for me is usually only 50-54 degrees.  I just looked at Ron Wallace's night time temperatures for July of least year and he is usually between 60-70 degrees at night.  His highs typically don't get much more than 90.   So I would take his environment over my greenhouse every time.  For me, the greenhouse is just a way to try to get things closer to normal.

I hope you enjoy the video.  I hope it saved you some time, got you some good ideas, helps you grow bigger and saves you some money.

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