Natural gas water heaters carry labels that identify their energy efficiency. Close off any of your rooms that aren't occupied - they're expensive to heat or cool. Natural gas heating provides you with instant warmth with no warm-up phase, so it's more efficient. Choose the right size gas heater for your home or the area you are trying to heat. Gas heaters will work more efficiently if the manufacturer's recommended clearance spaces are maintained at all times.
Gas heaters are cheaper to run and produce lower greenhouse gas emissions than electric heaters.