I am a newbie at this so forgive me if this is the wrong place to post this. I would like to control the temperature in a root cellar using Arduino. I checked on Instructables.com, Makezine.com, freeduino.org, and generally did a web search for any information on anyone that has already done this project or something similar. The closest thing that I found was a controller for temperature/humidity in a mushroom growing tank.
What I would like to do is open vents to let in cooler air at night. If someone has already done this, I have several questions for them.
How much of a temperature differential do you need before opening the vents?
Will a simple "hot air rises" system work or will I need a fan(s)?
At what outside temperature do you shut the vents to prevent freezing any vegetables?
I live in a very arid part of the country. Adding this cooler air will also decrease the humidity which is undesirable.
Any suggestions on adding humidity back to the cooler air?
Thanks to anyone who has any ideas, suggestions, or help!
- The temperature differential can be as little as you want (or as large as you want). If the outside is cooler than the inside, open the vents.
- I would think a fanless system would transfer the heat just fine. Image opening your window overnight, the inside cools to the outside temperature eventually.
- I would shut the vents before the inside drops below 32F or 0C.
- A humidifier
Thank you for your reply; I appreciate it. But perhaps I need to add some more detail to my questions.
1)There has to be a certain temperature differential for the air to begin to flow spontaneously. The intake pipe is approximately 15 feet in length and the outflow pipe is roughly 7 feet long with both being 3 inches in diameter. Overcoming the inertia of the air in these pipes may take a substantial temperature difference. (A similar problem is sometimes encountered starting a fire in a fireplace. You have to hold a lighted newspaper in the flue to get a draft going for the fire. Otherwise the smoke comes into the room instead of up the chimney.)
2)Due to the above, will I need a fan to at least start the air flow?
3)A humidifier will add moisture but it will also add heat (from the motor running, friction in the parts, etc). Most root cellars that I am aware of, do not use a humidifier for that reason. What I had in mind was a non-heat generating system. For instance, if a fan is going to be required, using a porous type of material with water dropped/sprayed on to it and forcing the air thru that.
I was hoping that someone else had already thought of this use for an Arduino and would have real-world experience actually running a such a system in their root cellar.
Thanks again for your reply. I appreciate any and all help.