BDV500 Series 42" R / T Vent Convertible Direct Vent Fireplace, Natural Gas or Propane Gas, Millivolt Control with On/Off switch and Manual Variable Flame Height Control or Electronic Ignition The BDV series of fireplaces offers a classic fireplace design in a range of sizes. Enjoy the flickering flames with viewing areas from 486 to 795 square inches and the warmth of BTU's ranging from 15,000 right up to 26,000. Operating your BDV fireplace is simple with an illustrated deluxe control panel. All BDV fireplaces come with standard black louvers but choose from a range of optional accessories and finishes to give your Monessen BDV direct vent fireplace a custom look that fits seamlessly into your decor.