It seems like forever since we wrapped up the pit garden construction process. (ok well it’ll never be finished, but once we got a bit planted the pressure was off) Since then we’ve planted some seeds, watched them sprout, and have been spending quite a bit of time figuring out how to work this new greenhouse.
Since we’re starting in Winter, temperature control and additional lighting have been top priorities. I’m going to write another article soon specific to what we’ve learned about heating our garden, but this post is about how we monitor the temps and work the systems remotely. There are very expensive professional greenhouse solutions, but I was hoping to use things we had around the house and office already (I’m in IT), as well as some other inexpensive items to get 80-90% there for 20% the cost.
I’ll admit it, I can be lazy. Especially when it’s 5 degrees out and blowing snow sideways, so a top priority was to enable management from the comfort of our cozy home. We have two different types of remote temperature sensors in different locations around the pit. The first is an Ambient Weather WS-10 weather system. We already had one of these to monitor the chicken barn and outside temps so added a sensor for the pit.
The next device I added was a La Crosse Alerts Wireless Monitor System with probe. This little device attaches to your home network wirelessly and sends the temp and humidity readings up to a website. This allows graphing of the changes over time in a nice web interface, as well you can check it from your smart phone remotely when you’re not home.
The other killer feature of this website is that it lets you set alert temperatures and text your phone if you’re outside of range. This has helped me numerous times when I wasn’t constantly monitoring the temps in the pit and we needed to adjust something to keep the plants happy. The probe that comes with it also lets us monitor the temperature within the dirt not just ambient temperature.
I’ve been using electric heat, propane heat, and our 1000W grow light (More info) to adjust temperature, humidity, and of course provide extra light on days we’ve had the tarp covering all day in a snow storm. Yet again, 10 trips a day out in the cold was not my idea of fun, so we installed a system to remotely turn on and off electrical items in the pit. The first thing you need to do is extend your network out into the greenhouse. I used a Netgear wireless bridge I had from work to connect to our wireless router in the house. This bridges from wireless and lets us plug in an ethernet wired device to be controlled on the wireless network.
Then you plug this into a Web Power Switch by Digital Logers. This device is normally used in server rooms to control the physical power to servers, but also happily turns on lights, heaters, a future irrigation pump, etc. You can actuate each port via the buttons to the right of the status screen, or just browse to a web site built into the device from the comfort of your home.
The final piece of logging I do is checking in on the electric heater by watching the power usage of our solar system. The system has a control module that records generation and usage by the different meters on our property. By looking back over night, I can see how much the electric heater had to be on to keep the temps where we want them.
In the image above the little heater ran most of the night since the day before there was no sun and the heat sinks didn’t gain much energy. I can also see how much our solar was able to defray the cost of this heavy night of heating. In our case though we’ve over generated earlier in the year, so we have quite a credit before we owe anything. That said, I’m convinced propane is a much better heat source during these coldest months when the sun and pit just aren’t enough to keep things warm. Electric heat will eventually just be supplemental.
Let us know what you do for your greenhouse monitoring and automation in the forums!