You're on the right track thinking about different ways to detect when the hood is on and then activate the damper. Here's a breakdown of the options, their pros/cons, and my recommended approach, keeping in mind you want to keep it simple and safe

Option 1: Direct Tap into Range Hood Wiring (Generally Not Recommended)
Description

Tapping into the power wires that feed the range hood to power the damper directly.

Pros

Simple in theory.

Cons



Safety Issues

You're potentially modifying a UL-listed appliance, which could void its warranty and create a fire hazard if not done properly. You're messing with high voltage.

Code Violations

This could violate electrical codes, especially if the damper's power requirements overload the hood's circuit.

Hood Functionality

You could interfere with the hood's internal electronics or motor.

Difficult to do Correctly

You would need to know the exact type of power that the makeup air damper needs, if its 120V or 24V

Option 2: Current Transformer (CT) at Electrical Panel Description

A current transformer clamps around the wire feeding the range hood circuit breaker. When the hood draws current, the CT induces a small current in its secondary winding, which then triggers a relay to open the damper.

Pros



Non-Invasive

You don't modify the range hood itself.

Safe

The CT is isolated from the main power wires.

Cons



More Complex

Requires understanding of current transformers, relays, and low-voltage wiring.

More Expensive

CTs and relays add to the cost.

Calibration

May require some adjustment to ensure the CT triggers reliably at the hood's operating current.

Option 3: Dedicated Interlock Relay Description

This is what you want to do. The range hood will need to have a standard outlet that plugs into the wall. You can get a smart outlet that has two outlets. When the outlet detects power draw from the hood outlet, it will then enable the second outlet to power on. This is a clean, safe, non-evasive method.

Pros



Simplest Installation



Safest and easiest method Low Cost Cons



More expensive than direct tapping into the range hood wiring.Recommendation: Option 3 - Dedicated Interlock Relay

Option 3 is the cleanest, safest, and easiest option to install. If you want to go ahead and do option 1, then it is highly recommend that you get a certified electrician. They can assess the situation and do all the wiring for you. If you do not know what you are doing you can get seriously injured, or even killed.

Important Considerations



Local Codes

Always check your local building and electrical codes. Makeup air requirements vary greatly by location.

Professional Installation

If you're not comfortable working with electrical wiring, hire a qualified electrician. It's always better to be safe than sorry.

Damper Compatibility

Ensure the damper you choose is compatible with the control method you select (voltage, current, etc.).

Before you start ANY electrical work



Turn OFF the breaker that supplies power to the range hood circuit.* Test with a non-contact voltage tester to ensure the circuit is de-energized.Good luck with your project! Let me know if you have any more questions. Flag for review