Installed it and am using the carbon filters. Finding the right filters was a bit tricky so I just ordered them online. Love the look of it, but installation took quite a bit longer than expected and we had to add some wood against the wall inside the flu to secure the top. I still asked don’t think I have hiked in the carbon filters right-i have one in each side of the motor-they are round and not carried at HD or Lowe’s. You have to open the 3 panels in the underneath side to get access to where the filters need to go.