Gas fire pits are rated for heat in BTU's (or, British Thermal Unit). A higher BTU means you can generate more heat and that heat will reach further than a lower BTU model. This is an important factor to consider when reviewing your temperature needs. Are you heating a small patio? Then you'll likely want a lower BTU unit. Is your fire pit front and center in a large backyard? You'll want a fire pit with greater BTU capabilities to cover more ground.