Google Nest to control Infra Red Heating Foil

[Sun-light]

Hello

I would like to use a Google Nest learning thermostat to be the controller of infra red heating foil. The foil just has a positive and negative input. Low wattage. 

We just need to turn it on and off or set a temperature setting to turn it on or off

Kind Regards.

Kevin.

[Bladerunner]

Hello, what you need is a relay. The relay will need to be at a rated amperage above the rated amperage of the foil. Fairly complicated. Things to consider.  Do you have spare capacity to supply the foil without overloading the circuit? Available space for the relay and it’s containment enclosure? 

[Sun-light]

Many thanks Bladerunner, do you know the type of relay we will need please? In this case it will only be a paor of 900 x 500 pieces of foil which will be used to heat wall panels. 

[Bladerunner]

The relay size is determined by the voltage and amperage. For example here in the uk. If I was to control a bathroom heater that is 230 volt AC at 1 kilowatt. You convert the kilowatts to watt which is 1000 watts and then divide the watts  by the voltage. Which is 4.35 amps. So I would source a 20 amp relay with a 230 volt coil. You could use a 10 amp relay, but I know that I can purchase a 20 amp for the same cost. Here in the uk, we don’t really go over 3 amps total load on the control side of heating circuits. And that would have no real impact on load adding a relay coil. The nest thermostat will then connect to the relay coil A1 side and the neutral to A2. The tricky bit is now determining the heater supply. I’m not comfortable guiding you on this side. If you get it wrong, there could be an overload and worse case a fire. An electrician for example will determine what the total load would be and decide whether a new circuit is required from the fuse board or whether an addition can be made to an existing circuit. In all cases You should have additional earth leakage protection as well as short circuit and overload protection. Hope this helps. 

[Sun-light]

Many thanks Bladerunner. We will give it a try. 

[MelbaDT]

Hey folks, 

Appreciate your answers here, Bladerunner. 

Sun-light, glad to hear that you've got the answer you're looking for. Feel free to let us know if you have further questions in mind. 

Best, 

Melba

[Ryan_G]

Hey everyone,

I'd like to jump in here and check if you've seen Melba's response. Let us know if you need more help by replying to this thread.

Thank you for your help, Melba.

Thanks,

Ryan

[Ryan_G]

Hey there,

Thanks for being here in the Google Nest Community. 

I'd like to bump in here and make sure that you’ve seen our response.

Please let us know if you have any other questions or concerns as I will be locking this thread in 24 hours.

Have a great day.

Best regards,

Ryan

[Ryan_G]

Hey folks,

I just wanted to follow up and see if you're still in need of help. Please let us know as we would be happy to answer any questions you may have. 

Best regards,

Ryan

[Ryan_G]

Hey there,

Thanks for being here in the Google Nest Community. 

I'd like to bump in here and make sure that you’ve seen our response.

Please let us know if you have any other questions or concerns as I will be locking this thread in 24 hours.

Have a great day.

Best regards,

Ryan

[Bladerunner]

Thank you. I think we can wrap this one up. 

[Ryan_G]

Hey Bladerunner,

Thanks for the reply and for the update.

We're glad to see you here sharing your thoughts. We'll give this thread a couple of more days to let other users share their experiences.

Best regards,

Ryan