Product Overview
Base Price shown is for FIREBOX with Stacked Grey Brick Traditional LINER ONLY. A Burner and Log Set are all required. A Blower Fan is available but not required! The price displayed will update based on your selections. If you need help designing your firebox, please contact us.
With flexible installation options, the Exacta firebox can be installed into a pre-existing wood-burning fireplace (converted with a gas line), into a wall or even into a free-standing cabinet. A vent-free firebox is simply the metal combustion chamber needed to house a log set and burner. The Exacta BUF42-T includes a Traditional Grey Stacked Brick liner for a more traditional fireplace look.
The Exacta firebox offers a clean front (not louvered) and a large 42" x 24" viewing area. The safety screen can be tucked away into hidden side pockets offering a full, unencumbered view. The framing dimensions of the BUF42 are 48-1/2"w x 34-1/4"h x 19-3/4"d , while the overall size of the Exacta BUF42T firebox are 48" front width x 34"h x 20"d with a rear width of 37-1/4".
Firebox unit dimensions:
- 48" Front Width
- 27-1/4" Rear Width
- 37-1/4" Height
- 23" Deep
Framing dimensions:
- 48-1/2" Width
- 34-1/4" Height
- 19-3/4" Deep
Hearth dimensions (for burner/log sets):
- 38-7/8" Front Width
- 30-3/8" Rear Width
- 25-1/2" Front Height
- 22-5/8" Rear Height
- 15" Deep
A log set and burner are required. Check out our selection of available log sets.
The BUF42-H firebox can accept most 24" and 30" vent free log sets (sold separately). Below are the Monessen Log Set options available for this firebox. With zero clearance, the firebox can be installed flush against any surface like drywall or wood. Vent Free Natural Blaze Burners are available for use with each of these log sets:

Additionally, Monessen offer Natural Blaze 24" burners with Natural Blaze Technology. This technology helps provide taller, more lively flames for a truly realistic fire in your vent-free firebox. Beautiful yellow flames are instantly achieved every time your burner is switched on. A Natural Blaze 24" burner can be used with either 24" or 30" log sets.
- Millivolt Valve (NB24PV or NB24NV) - standing pilot with on/off switch and manual variable flame height control and remote ready (remote sold separately)
- Electronic Ignition with Intellifire Plus System (NB24PIF or NB24NIF) - intermittent pilot/electronic ignition, 3 step flame adjustment and Touch Screen Thermostat Remote included.
With a vent free firebox, fresh air is drawn in at the bottom of the firebox, and warmed air is expelled into the room from the top. The Exacta firebox features an angled top design to help direct the warm air out for maximum efficiency. A blower (GFK-160VF) can be added to help circulate the warm air.
An optional outside air kit is also available for vent free fireboxes. The AKD introduces fresh, outside air into the firebox. An outside air kit is recommended as an accessory when installing a vent free appliance into newer, more air tight construction for an adequate supply of fresh air. Some local building codes may require an outside air kit.
Vent-Free Products Cannot Be Shipped To The State Of California.