Giveaway Inkbird ITC-306T heating temperature controller

Hi @marina - I would say that there is an argument for a cooling function; for example, I have a 10 x 8 greenhouse, and in the height of summer it can get frighteningly hot in there even with the double doors and four roof windows open. A thermostatic control such as your ITC-308 would allow me to have a fan or fans ready to come on to assist with lowering the temperature.

Indeed, I personally would be inclined to take that one step further and have the thermostatic control switching on and off a 5v switch mode power supply with a decent rating (1000mA regulated maybe) and then have 5v DC fans mounted in the roof windows (maybe three PC fans mounted onto each window sized frame) - the supply could then also easily cope with AC mains pedestal fans for really robust cooling.

 

Hi @marina29 - I will try and make time tomorrow or Monday to draw up a diagram; I would guess that your technicians would be capable of making modular kits that could be purchased by gardeners to fit their requirements.

 

I guess it would work well with my home made heated propagator. I built it in 1976 and although it still works I can't set the thermostat properly as all the markings on the dial are worn away!

 

OK, please excuse my really rough attempt at drawing, but here is what is in my head:


A simple mains adapter on the cooling output of the ITC-308 would allow for a mains fan (perhaps situated just inside an open greenhouse door) to be switched on/off at the desired temperatures. At the same time, a mains supply could also be switched on that is connected to a switch mode power supply with enough capacity to run a few fan modules (think along the lines of a laptop charger), with an output of 5v DC. Note - the star shapes above represent DC brushless fans

Here is an example of a circuit diagram (not mine) for a switch mode power supply:



Then have fan modules connected to the DC output from the switch mode power supply that would come on when the power is switched on for the cooling circuit.

The fan module itself could be made out of some sort of semi-flexible plastic to allow it to be clipped in just under the opening for the greenhouse roof window; they would need to be able to stretch or contract to fit various size openings, but I am sure that your designers could get around that problem fairly easily.

Fan module with 4 x 5v DC brushless fans:


Suggested type of fan:



You could have a range of plug and play modules, with switch mode power supplies to handle 2, 4, 6 or 8 fan modules, connection cables to connect everything, and then the customer would simply have to buy the ITC-308 and then whichever number of modules they wanted to suit their greenhouse.

Even without a mains fan by the greenhouse door, if there was a fan module installed into each window opening, it should help cooling quite significantly by forcing the warmer air to exhaust out through the fans, and in turn draw cooler air in from an open door.

The one really important thing your designers would have to bear in mind, however, is NOT to try and cut the price down by changing the switch mode power supply to a capacitive dropper - the last thing you would want in a metal framed greenhouse where there is water/humidity is a power supply that is sitting referenced to mains.