33-inch gas logs are the perfect addition to your old unused fireplace. If your firebox has been sitting for a long while, you can always upgrade it to a gas-fueled fireplace. Gas-powered fireplaces are easier to clean and maintain over time so you know making the switch is the right choice for you. If your firebox has been sitting for a long while, you can always upgrade it to a gas-fueled fireplace. Gas-powered fireplaces are easier to clean and maintain over time so you know making the switch is the right choice for you. 33-inch gas logs are the perfect addition to your old unused fireplace.