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Greenhouse Thermostat? Help!


Formerly known as Pineapple
I need a thermostat for my 6ft x 8ft greenhouse to run my swamp cooler and my heater. I want it to stay between 50F and 80F as a target temperature range. Can somebody point me in the direction of a good thermostat or a website that I can buy one from?

I would really like one that I can just plug both the heater and swamp cooler into and plug the thermostat into the power strip in the greenhouse. Do they make those? Anyone have a link? What do you use for your GH thermostat?
wouldnt a hygrotherm work do you what the wattage is for the swamp cooler
They make what are called portable thermostats which can be plugged into any outlet and the device then plugs into the thermostat. I am not aware of any that will do both cool and heat in a single unit though. Probably easier to get separate units, one for the heater and one for the cooler.
Can you control both a heater and a cooler with a single unit though? I have never used one but from the description online it sounds like it will do either or but not both?
Yeah he'll have to decide which one he wants it to do, heat or cool depending upon time of day/time of year.

I have mine set to cool day and night year round but you can have it warmer at night and off during the day depending on settings. If he's using a swamp cooler I assume he's using it for both cooling & humidifying so that could potentially go into the humidity input cord and he's wanting a heater for night time which could be plugged into the thermostat input cord. In summer he'd have to switch it around and maybe put an exhaust fan on the temperature input to push out that hot GH air and switch some of the controller settings around.
Ach... The heater is 12.5 amps at 120v (1500w) and the swamp cooler is 5.5 amps at 120v (~600w)... So it must work with those. I see the one you have linked to, Tony, should work. I guess I need two. Do you know where the plugin is on the device? Is it the three prong hole I see on the back of the plug head itself?

Thank you for all your answers, everyone! This will really help me out since I won't have to set the heater every single night. Should help cut the electric bill down to a fifth of what it is now.
Here is another slightly cheaper version of what Tony posted PSP300
I believe this can also be set up to not run at certian times and such.

I have never used this, so I cannot vouche for its quality.
Here is another slightly cheaper version of what Tony posted PSP300
I believe this can also be set up to not run at certian times and such.

I have never used this, so I cannot vouche for its quality.

Thanks! I only see one plug-in place on there though and can't imagine where another plug-in spot would be available on that device. I need something that can control a heater and a cooler, so I guess I have to go with two of what Tony suggested. They look pretty sturdy.
  • #10
I am pretty sure if you wanted to, you could modify the one Tony linked to do both heating and cooling. I might have to order one and see if they are built like I am guessing.
  • #11
I use both of the thermostats Tony suggested with great success. It really helps with the environment and works well if you have to go away for a week or so.
  • #13
Matt that I looked for atleast a hour last night for something just like that! Just couldn't find one.
  • #14
Oh nice! Kinda what I expected though price wise. Most of the time you see the single prewired type for $60-70 too. Which is why I suggested the ones I linked to. They looked like pretty good quality for considerably less. There really isn't alot to the nondigital ones... just an open/close spring contact and wire plastic etc...
  • #15
The Ranco thermostats have been used by plenty of reptile keepers too, and generally have a good reputation.
  • #16
There is kinda a price limit... I could buy one of the more expensive digital ones, but I really don't want to lol. I think $80 for two of what Tony suggested sounds like a fair enough deal.

Just curious, but does anyone know how the temperature settings on it would work out? I read that on the exact model, you set it to a temperature and it keeps it at that. So say it is a hot summer day and the greenhouse is in full sun... I set it for 82F and it comes on when it goes above 83F, but since the swamp cooler is so fast at cooling the GH down, it goes right down to 81F and shuts off. But remember it is in full sun on a hot summer day, so it immediately heats back up. Is there something on there to prevent this situation or will the swamp cooler be turning on and off the entire day? Kinda a confusing question, but I'm curious of how it would work. ???
  • #17
The metal probe analog controllers generally have about a 4 degree F window in which they function, so if you had the controller set to 80 degrees. It would turn on at approximately 82 and off again at approximately 78.
  • #18
Maybe you can do this with mechanical ones Im not sure, but with digital ones you can set the differential for when it kicks on and off. The Ranco thermostat would allow you to set this function.

One thing to remember Pine, these thermostats completely cut power off and on. This means you must make sure the heating or cooling unit you're using turns back on after the power has been cut. You can test this by unplugging the unit and plugging it back in, if its heating/cooling after you plug it in again you'll be fine. Many new heaters and cooling units have digital thermostats and are designed in a way that doesn't allow this style of thermostat to be used.
  • #19
Neither have digital thermostats on them so I think they should be fine. I have the swamp cooler plugged up to a timer, so it is definitely fine. I'll try the heater though.
  • #20
Two thermostats ordered. Thank you to everyone who has helped! I'll post an update on how they work when they get here. :)