Awesome...Mine says it has a Triac Silent switching relay, Would this matter?
Yep, unfortunately.
I've opened the package...
This thermostat cannot be used with the following:
-resistive load under 2A
And that's why. This thermostat uses a solid-state switching device known as a triac instead of relay contacts. A triac is essentially just a big transistor. They're used because they don't go
KLIKK every time they switch. Downside is that to keep the current flowing properly in them, there's a minimum current rating. 2A @ 240V is 480W. Only the very largest blowers will come close to drawing that amount of power.
Will this still work?
Sorry, no- it won't.
Swap it out for a unit with a relay. Chances are, your blower will draw 1A or less if you're on 240V.
When I discuss 'reversing the logic of a thermostat', I'm talking about making a thermostat intended for a heating appliance suitable for a cooling fan. A heating thermostat switches on (contacts close) when the temp falls below the setpoint. A cooling thermostat switches on (contacts close) when temps rise above the setpoint.
If for example, you have something in your junkbox like an old thermostat for a waterbed, it can be used to turn a relay on and off which can switch a fan motor. The relay you select from Ye Olde Electronics Junque Shoppe can have both normally open (NO) and normally closed (NC) or just NC contacts.
In practise, the heating thermostat's contacts will open above the setpoint, opposite of what you need for a cooling fan. Use the heating thermostat's contacts to switch a supply voltage to the coil of a SPST (single pole, single throw) NC relay. You can use DPST or 4PST relays as well, but you'll only need one pair of NC contacts. All you need is a pair of contacts that are connected when the relay coil is not energised.
You have to come up with some sort of power supply to operate the relay's coil. An old plugpak power supply or battery charger will do fine. Just match the supply voltage to the relay coil voltage.
The waterbed thermostat switches off at and above the setpoint, removing the voltage to the relay, so the relay's NC contacts will close. Use that set of NC contacts to switch your cooling fan. When the temp is below the setpoint, the heating thermostat's contacts will close, completing the circuit from the power supply to the relay coil, opening the NC contacts.
Seems complex, donit?
It is, a bit. However, this is exactly what has allowed me to use an old waterbed thermostat to run my flowering area's exhaust system for the last 8 years or so.
That's why I like the little Computime thermostat so much. Makes the task cheap, simple and reliable. No external power supply nor wiring needed. Has both NC & NO contacts so it can work for heating or cooling. Bang, $40, done.
