Yes, you can use an elbow in your ductwork to install your range hood. We recommend using no more than two elbows in your entire duct run. Otherwise, resistance builds up in the duct, causing turbulence.
If you need to use an elbow, make sure it is at least 18 inches from the connection to the range hood. If the elbow is closer than 18 inches, the kitchen air will struggle to make it outside your home.
Also, make sure that you have at least 24” between elbows in your ductwork.
For more advice on range hood ductwork, check out the articles below.