BUILDER SERIES direct vent fireplaces are an economical system with all the latest technology and AFUE Heater Rating. Standard features include rolled louvers, tough texture powder coating, and convenient, dual access pre-wired electrical J box. Our 36" Cottage direct vent models feature beautiful new combination split oak ceramic fiber gas logs with multi-tiered flame patterns and glowing ember beds for an outstanding flame presentation. BTU range is 15,000 to 21,000 for both fuel types.