Would it be possible to make a whole house fan smart? In order to turn it on and off i have to pull the chain that you can see in the photo. I was wondering if it would be possible to add a zwave relay or something like thag so i can use it with HA. Any advice would be more than welcome. Thanks!
What’s the chain attached to?
Be careful with the relay, need to make sure it can handle the inrush current of the motor. Most of the smart relays are designed for lighting loads, not motors. But it should be doable, would be good to have window sensors though, so it didn’t turn on if the windows weren’t open.
Could you provide some more guidance? Is there a relay that can handle the load that you can recommend? Is there a better alternative than a relay?
Not really, it’s very location dependent. For example, I use a Jasco Zigbee switch to turn on a Booster Fan with my HVAC unit, when I was looking for a relay, most of them either weren’t rated or were rated too low for the blower motors hp rating. You need to determine the motor rating on your house fan and then find a relay that will support that. This is an excerpt from the manual for the jasco I use, you can see its good for up to a ½ hp motor, that may be enough in your case, but you’d need to confirm and that’s assuming the z-wave version is rated the same and that you’re in North America, etc.
@ignacio82 - I believe Steve has an important question here. Would be great if you could elaborate what your whole house fan setup looks like, how it gets powered, how it gets controlled, how it gets triggered and stopped today, how you would want it to be triggered and stopped, is it based on temperature? based on humidity? or do you just want an extra switch on your phone so that you can poke your screen whenever/wherever you want? etc.
You may want to consider using a power relay with contact closure inputs, such as the Functional Devices RIB01BDC (these are available from a variety of electrical supply houses online for around $25). I am using ControlByWeb X400-series modules to control relays with a simple webhook interface from HA. The CBW modules work very well but are expensive if you need to control only a single device; I’m sure there are ZWave relays available that would do the job.
I’m guessing the chain also mechanically opens or closes the louvres, which a relay will not do.