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Monessen > BUF Series Vent Free Firebox

Flexible Installation Options

Our BUF line of vent free fireboxes offers a zero clearance design. With a true 36- or 42-inch brick-to-brick opening, this series is a versatile vent free option for any design application.

Save Energy And Maximize Heat

Vent free gas fireplaces (available in natural gas and propane) are a safe, green and energy efficient way to add heat to your home — in fact, they’re 99.9% energy efficient. Because they are vent free, none of the heat gets lost up a vent, flue or chimney. Instead, fuel dollars get transformed into heat-warming energy. Plus, you can always be assured of a heat source, even in the event of a power outage.

Install It Where You Want It

Because vent free fireplaces are designed to be installed and operated without a chimney, flue or vent, they can be installed in locations in your home where it would be impossible to install a vented fireplace. They provide the most economical installation, only requiring a connection to a gas line.

Create Your Own Look

With multiple facing and firebrick options available, you can tailor the look of the fireplace to suit your tastes and décor.

You’re In The Clear

Monessen vent free fireplaces allow for zero clearance installation, which means they may be installed flush against any combustible surface such as drywall or wood. This gives you added flexibility and helps save installation dollars when deciding where to install your fireplace, whether on an interior or exterior wall.

Complete Your Look

Monessen offers a selection of vent free log sets (sold separately) that are a perfect complement to your new fireplace. Ask your dealer for details.


Accessories That Fit Your Home And Lifestyle

Blower Kit

Power up your heat output with a variable thermostatic forced air blower.

Outside Combustion Air Kit

Draws in outside combustion air for your firebox rather than pulling it from the room. 



  BUF500 BUF400
Size 42" 36"
Dimensions 46 (W) x 34 (H) x 21 (D) 40 (W) x 34 (H) x 21 (D)
Hearth Dimensions 41-1/2 (W) x 21-1/2 (H) x 17 (D) x 26-3/8(RW) 35-1/2 (W) x 21-1/2 (H) x 17 (D) x 20-3/8(RW)
Fire Viewing Area 42" x 21-9/16" 36" x 21-9/16"
Viewing Style Front Front
Venting Vent Free Vent Free
Heat Distribution Radiant/Circulating  Radiant/Circulating 
Termination None  None
Certifications CSA Design CSA Design


Visit our showroom today and speak with one of our knowledgable sales staff to begin designing "Your Fireplace".


Support & Downloads

Product Brochure

Owners Manual

Specifications Sheet: BUF400

Specifications Sheet: BUF500