This section permits by rule combustion units designed and used exclusively for comfort heating purposes employing liquid petroleum gas, natural gas, solid wood, or distillate fuel oil. Distillate fuel oil includes diesel fuel, kerosene, and heating oil Grades 4 and lighter. Distillate fuel oil does not include heavier residual oils such as Grades 5 and 6 fuel oil. Combustion of bark chips, sawdust, wood chips, treated wood, or wood contaminated with chemicals is not included. Used oil that has not been mixed with hazardous waste may be used as fuel in space heaters provided that:     
       (1) the space heater or combination of space heaters at the same account have a maximum capacity of 1.0 Million Btu per hour (MMBtu/hr) provided each individual heater is not greater than 0.5 MMBtu/hr;      
       (2) the combustion gases from the heater(s) are vented to the ambient air in accordance with the following requirements:                (A) through an unobstructed vertical vent; or                 (B) for a stack with a cap;                    (i) for a flat roof, through a minimum of a three-foot stack; or                     (ii) for a sloped roof, through a stack that is three feet higher than a point extending ten feet horizontally from the roof; and          
       (3) the heater(s) burns only used oil that the owner or operator generates on-site or used oil received from household do-it-yourself used oil generators.      
     Source Note:        The provisions of this §106.102 adopted to be effective November 15, 1996, 21 TexReg 10883; amended to be effective September 4, 2000, 25 TexReg 8653