Making my AC fan speed controller smart

Hardware
1

Hi!

My entire house ventilation is controlled by this single fan controller: Transformer fan speed controller 1 Amps

I want to be able to adjust the fan speed via automations whenever I need to circulate air faster or slower.

What would be a good way to approach this? I can solder and do basic DIY stuff, but don’t have too much experience with HVAC systems. Ideally, I would like to connect it via Zigbee, but tasmota or ESPHome via wifi are also acceptable. Theoretically, I could even run wires from the raspberry pi running home assistant there, as the controller sits right next to it.

2

Have you had a look at this?

It is from the same company, but uses ModBUS.

And ModBUS is a supported platform in HA as I can remember.

The swap would be straightforward. But have a look how ModBUS works and what other equipment you would need.

1 Like
3

If swapping the control unit out for a modbus version does not work then you might be able to replace the switch with a bank of relays (see link below) which are driven by a Wesmos D1 Mini running ESPhome.

https://www.aliexpress.com/item/1005002608790272.html?spm=a2g0o.productlist.0.0.2cd77d1709b2cj&algo_pvid=ee824167-454e-4df3-bf8c-b19b84505515&algo_exp_id=ee824167-454e-4df3-bf8c-b19b84505515-13&pdp_ext_f={"sku_id"%3A"12000021377222201"}

The video below by 3ative shows how he did something very similar for a desk fan with 3 switches, if you did not require the LED’s then this could be simplified for your application.