Superior VRT3542WS 42" Firebox with 28" Tall Opening, White Stacked Liner

Superior VRT3542WS 42" Firebox with 28" Tall Opening, White Stacked Liner

The Superior VRT3542WS is the 42" firebox in Superior's VRT3500 series of universal vent-free fireboxes: a smooth black face around a 28" tall, full-width opening lined with white stacked refractory panels and floor, with mesh fire screens. It is the enclosure only. The fire comes from a vent-free gas log set and burner that you order separately, and with no chimney or vent pipe, the heat stays in the room.

The firebox takes a vent-free log set listed to ANSI Z21.11.2, rated no more than 40,000 Btu/hr, that fits inside it. Superior's Double-Flame (18" and 24"), Triple-Flame (18" and 24"), Nature-Flame (18", 24" and 30") and Mega-Flame (24" and 30") logs fit; they and their burners are listed below. The hood is optional, and a blower, arched screen door and outside air kit can be added.

The same firebox comes with white herringbone refractory (VRT3542WH), and the VRT3500 also comes in 36" (VRT3536WS). It can't be installed in a bedroom or bathroom, and the room has to be large enough or ventilated for the log set you choose; see Installation Requirements.

Key Features

• 42" wide, 28" tall opening; inside, 41" wide at the front, 29-1/4" at the back and 17-3/8" deep
• Tall enough for Superior's Mega-Flame log sets
• Vent-free: no chimney or vent pipe
• Takes ANSI Z21.11.2 vent-free log sets up to 40,000 Btu/hr, ordered separately
• White stacked refractory panels on the back, sides and floor
• Smooth-faced design with a textured black powder coat finish
• Mesh fire screens included
• Heat deflection hood optional
• Optional single-speed or variable-speed blower
• Optional arched twin-pane screen door in textured iron
• Optional outside air kit
• Listed to ANSI Z21.91 as a ventless firebox enclosure
• 20 year limited warranty on the firebox

What's Included

• Firebox with white stacked refractory panels on the back, sides and floor
• Mesh fire screens and rods
• Junction box for an optional blower
• Installation and operation manual

What to Order With It

Required – Vent-free logs, ordered separately (pick one set):

• Double-Flame Crescent Hill Logs, 18", Concrete (LVD18CH)
• Double-Flame Crescent Hill HD Logs, 18", High Definition (LVD18CHHD)
• Double-Flame Golden Oak Logs, 18", Ceramic Fiber (LVD18GO-B)
• Double-Flame Crescent Hill Logs, 24", Concrete (LVD24CH)
• Double-Flame Crescent Hill HD Logs, 24", High Definition (LVD24CHHD)
• Double-Flame Golden Oak Logs, 24", Ceramic Fiber (LVD24GO-B)
• Triple-Flame Rugged Stack Logs, 18", Concrete (LTF18RS)
• Triple-Flame Wild Timber Logs, 18", Concrete (LTF18WT)
• Triple-Flame Rugged Stack Logs, 24", Concrete (LTF24RS)
• Triple-Flame Wild Timber Logs, 24", Concrete (LTF24WT)
• Nature-Flame Granite Ridge Logs, Concrete, 18", 24" or 30" (LNF18GR, LNF24GR, LNF30GR)
• Nature-Flame Silverstone Timber Logs, High Definition, 18", 24" or 30" (LNF18ST, LNF24ST, LNF30ST)
• Mega-Flame Mossy Oak Logs, 24", Concrete, two boxes (LMF24MOA/B)
• Mega-Flame Mossy Oak Logs, 30", Concrete, two boxes (LMF30MOA/B)
• Mega-Flame Giant Timbers Logs, 30", Concrete, two boxes (LMF30GTA/B)

Required – Burner for the logs (pick one: Double-Flame logs take the VD1824 burner; Triple-Flame 18" logs take the 18" burner and 24" logs the 24" burner; Nature-Flame 18" logs take the 18" burner, and 24" and 30" logs the 24" burner; Mega-Flame 24" and 30" logs take the MNF24 burner):

• Double-Flame 18"/24" Burner, Millivolt (VD1824NR/PR)
• Double-Flame 18"/24" Burner, Manual (VD1824NM/PM)
• Triple-Flame 18" Burner, Millivolt (TF18NR/PR)
• Triple-Flame 18" Burner, Variable with Remote (TF18NV/PV)
• Triple-Flame 18" Burner, Electronic with Remote (TF18NE/PE)
• Triple-Flame 24" Burner, Millivolt (TF2430NR/PR)
• Triple-Flame 24" Burner, Variable with Remote (TF2430NV/PV)
• Triple-Flame 24" Burner, Electronic with Remote (TF2430NE/PE)
• Nature-Flame Burner with Ember Bed, 18" or 24", Millivolt or Electronic (NF18/NF24)
• Mega-Flame MNF24 Burner, Millivolt (MNF24INM/IPM)
• Mega-Flame MNF24 Burner, Variable with Remote (MNF24INV/IPV)
• Mega-Flame MNF24 Burner, Electronic with Remote (MNF24INE/IPE)

Optional – Blower (the FBK-100 needs an on/off wall switch):

• Standard Blower, Single Speed (FBK-100)
• Blower Kit, Variable Speed with Wall Switch (FBK-200)
• Wall Switch Kit, On/Off, White (FWSK)

Optional – Hood and screen door (the screen door needs the hood):

• Firebox Canopy (Hood), Powder Coat (FC42)
• Arched Screen Door, Textured Iron (ASD4228-TI)

Optional – Outside air and touch-up paint:

• Outside Air Kit with Duct (OAK-UVFRC)
• Touch-Up Paint, Powder Coat Exterior (SCTPSAB)

Specifications

The firebox doesn't make heat on its own. The Btu rating, ignition and remote all come from the log set and burner you choose, and the room size rules under Installation Requirements depend on that input.

Dimensions and Framing

Firebox dimensions

Inside the firebox (for sizing logs)

Framing

Measure the framed depth to the finished surface of the back wall, so allow for drywall or other finish. Nail the firebox to the side framing through the full-length tabs at the top and bottom of the front face with 8d nails, and don't fill the space around it with insulation. The other corner framing dimensions are in the installation manual.

Installation Requirements

• Room air: a vent-free log set uses the air in the room. The space must hold at least 50 cubic feet for every 1,000 Btu/hr of all the gas appliances in it, counting adjoining rooms without doors. A 40,000 Btu/hr log set alone needs 2,000 cubic feet. A smaller space needs ventilation openings to another room or to the outdoors, as set out in NFPA 54 and the log set's manual.
• Bedrooms and bathrooms: the firebox can't be installed in a bedroom, other sleeping room or bathroom, or in a recreational vehicle.
• Log set: use only a vent-free log set listed to ANSI Z21.11.2, rated no more than 40,000 Btu/hr, that fits the firebox. Don't burn wood, a vented gas log set or anything else in it.
• Hood: optional. If you fit one, use only the FC42 hood made for this firebox, don't modify it, and don't use a hood that comes with a log set. The lower mantel heights below apply only with the hood on, and Superior's arched screen door needs it.
• Side walls and ceiling: keep a side wall at least 16" from the side of the firebox opening and the ceiling at least 40" above the top of the opening. No combustible material can be closer than 3" to the side of the opening, and anything that sticks out from the wall, such as a mantel leg or bookshelf, needs more room the further it sticks out (5" out needs 6" from the opening; the chart is in the manual).
• Mantel: without the hood, a combustible mantel or trim up to 6" deep must be at least 16" above the firebox opening, and deeper ones go higher, up to 10" deep at 24" (a 7" mantel needs about 18"). With the hood on, shallower trim can sit lower: 2" deep at 9-1/2", 4" deep at 13" and 6" deep at 16". Superior recommends high-temperature paint, rated 175 degrees F or higher, on the hood and the underside of a mantel.
• Wall above: the first 3" of wall above the top of the firebox, up to the header, must be non-combustible. A header can touch the top spacers but can't rest on them, and the spacers can't be removed, notched or cut. All framing above the firebox must support itself.
• Front: keep curtains, furniture and other flammable objects at least 42" from the front.
• Facing: only non-combustible materials such as marble, stone, tile or brick can overlap the black front face; seal the joints with non-combustible caulk. Non-combustible materials at least 1/2" thick can go above and beside the opening without restriction, as long as they don't block the heat-circulating air openings.
• Hearth and floor: no hearth extension is required. A raised one can be combustible (not carpet or vinyl) if it is no higher than the bottom of the firebox opening, 5-3/4" above the base. The firebox can sit on a combustible floor on a fully supported, level base; on carpet or vinyl, put a metal or wood panel under it.
• Gas: run a 1/2" to 1-1/2" inside diameter gas line through the access on either side before the wall is closed, with a sediment trap upstream. Propane needs an external regulator that holds tank pressure to 13" WC or less. Seal the holes with high-temperature caulk or unfaced fiberglass.
• Power: only an optional blower needs power. Run a 3-wire, 120 VAC, 60 Hz supply to the right side before the firebox is framed in, even if the blower will be added later; the wiring must be done by a licensed electrician.
• Cold climates: seal cracks around the firebox with non-combustible material and insulate outside wall cavities. On a cement slab, a plywood platform under the firebox keeps cold from coming up into the room.
• Drafts: don't let fans blow into the firebox; drafts change the flame.
• Burn-in: the first few fires give off an odor from curing paint. Ventilate the house and don't run the blower until it passes.
• Massachusetts: installation and repair must be done by a licensed plumber or gas fitter, following 527 CMR 30. The flexible gas connector can't be longer than 36", the shutoff must be a T-handle valve, the firebox can't go in a bedroom or bathroom, and a working smoke detector is required in the area where it is installed.
• Installation: must be installed by a qualified installer following the installation manual, the log set's manual and local codes. Superior calls for an inspection by a professional service person before first use and once a year.

Frequently Asked Questions

Does it come with logs?
No. Order a vent-free log set and a matching burner, both listed above: Double-Flame logs take the VD1824 burner; Triple-Flame 18" logs take the 18" burner and 24" logs the 24" burner; Nature-Flame 18" logs take the 18" burner, and 24" and 30" logs the 24" burner; Mega-Flame 24" and 30" logs take the MNF24 burner. Any vent-free log set listed to ANSI Z21.11.2, rated 40,000 Btu/hr or less, that fits inside (41" wide at the front, 29-1/4" at the back, 17-3/8" deep, 28" tall) can also be used. Superior's 30" Triple-Flame sets need a firebox at least 30" wide at the back, so they aren't listed.

Does it need a chimney?
No. The log set burns room air and the heat stays in the room, so there is no vent pipe to run. In exchange, the room has to be big enough or ventilated for the log set's input.

Can it go in a bedroom or bathroom?
No. It can't be installed in a bedroom, other sleeping room or bathroom.

Do I need the hood?
No, the hood is optional on the VRT3500. With the FC42 hood on, shallower mantels can sit lower (see the mantel question below), and Superior's arched screen door needs it.

How much heat will it give?
That depends on the log set. The Superior sets that fit run up to 40,000 Btu/hr on natural gas, the most this firebox allows.

Do I need the blower?
No, it's optional. It draws room air in through the side slots, warms it around the firebox and sends it out at the top of the opening. The FBK-100 runs at one speed from an on/off wall switch; the FBK-200 comes with a variable speed wall control. Power has to be run to the firebox before the wall is closed.

Can I put a mantel above it?
Yes. Without the hood, a combustible mantel up to 6" deep has to sit at least 16" above the opening, rising to 24" for a 10" mantel. With the hood on, a 4" mantel can sit 13" above the opening and 2" trim 9-1/2". A non-combustible mantel can go at any height. Our guide to fireplace heat management explains ways to keep the wall above cooler.

Warranty

Superior's 20 Year Limited Warranty covers the VRT3542WS against defects in materials and workmanship:

• Firebox body: 20 years
• Optional blowers: 1 year
• Parts not listed: 90 days
• Labor: paid at IHP rates for the covered part's warranty period, up to five years

Trim and paint are not covered. The warranty is for the original owner of a fireplace installed in the US or Canada. Full terms are in the warranty certificate.

Documents and Downloads

• Installation and Operation Manual
• Specification Sheet
• Smart Sheet
• Brochure
• Vent-Free Gas Log Brochure
• Warranty Certificate