The VRT4536 from Superior
A 36" vent-free firebox with a 30" tall opening and firebrick running to the front edge — no chimney, no vent run. The Superior VRT4536 is the enclosure half of a vent-free fireplace: listed to ANSI Z21.91, it hosts any ANSI Z21.11.2-listed vent-free gas log heater up to 40,000 BTU/hr input, sold separately. The White Stacked or White Herringbone refractory interior ships with the firebox, and the hood and mesh screens arrive with it. from $3,429.
Choose the VRT4536 if you want a masonry-look fireplace opening where a chimney or vent run is impossible and you want the brick interior in the carton — it frames to a 45-3/4" x 55" rough face, zero clearance at the cabinet, sits directly on an ordinary combustible floor, and burns the log set you pick separately.
It is not right for a bathroom, for a bedroom unless the log set you install is rated 10,000 BTU/hr or less, or for any bedroom or bathroom in Massachusetts, where vent-free heaters are barred from both statewide. It burns room air, so a tightly sealed space that cannot spare combustion air is also the wrong home for it. For those rooms, a sealed direct-vent fireplace such as Superior's DRT3000 or DRT3500 series is the one to look at instead.
Specifications
Frame a rough face 45-3/4" wide by 55" high, with the chase 29" deep to its back wall including finishing materials — the manual's Figure 8 charts the full framed enclosure at 61" x 86-1/2" for this size, parallel or corner. The cabinet is 45-1/4" wide and 54-3/4" high; the interior runs 35-1/4" across the front between the panels, 19" deep and 22-1/2" at the rear. Keep the ceiling at least 42" above the opening and flammable objects 36" from the front; a combustible mantel follows the stepped profile above the hood opening, where the permitted projection depends on the height — see Figure 7 on page 11 of the installation manual. Listed by PFS to ANSI Z21.91, Report F09-130.
How the VRT4536 compares to the other VRT4500 sizes
The three VRT4500 sizes share the same 30" tall opening, the same White Stacked or White Herringbone interiors and the same accessory list; they differ in width. This 36" runs from $3,429, against the 42" at from $3,649 and the 50" at from $4,089. The rough framing face steps from 45-3/4" wide here to 51-3/4" and 59-3/4" on the larger sizes.
Features
- 36" vent-free firebox with a 30" tall opening and firebrick extending to the front edge
- White Stacked or White Herringbone refractory interior ships with the firebox, bottom panel preinstalled
- Vent-free — no chimney and no vent run; the room supplies the log heater's combustion air
- Hosts any ANSI Z21.11.2-listed vent-free gas log heater up to 40,000 BTU/hr input, sold separately
- Fireplace hood and wire-mesh screens ship with the firebox
- Zero-clearance cabinet — framing can sit against the box everywhere but the standoff spacers
Answers to common questions
What’s included, what’s required, and what’s optional?
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Included in the box: 36" x 30" firebox opening with firebrick to the front edge; Refractory panel set — White Stacked or White Herringbone, bottom panel preinstalled; Fireplace hood and wire-mesh screens (must be in place to operate); ANSI Z21.91-listed firebox enclosure; 20-year limited warranty on body, firebox, and barrier.
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Required to complete the installation, purchased separately: Vent Free Burner/Log Set - any ANSI Z21.11.2-listed vent-free burner or log set up to 40,000 BTU/hr input — the firebox is the enclosure and burns nothing on its own; Gas Line - 1/2" black iron through the conduit sleeve on either side, run by a qualified installer and connected before the wall is closed.
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Optional: Outside air kits (AK4 sidewall, AK4F floor, AK4X collar-and-hood), refractory stain kits in Creamer, Rust or Cappuccino, and an approved cabinet mantel for freestanding installation — the firebox operates fully without them.
Does it need a chimney or a vent?
No — this firebox requires no outside venting or chimney, and nothing about it vents outside. The log heater it hosts uses air from the room, so the room must supply adequate combustion and ventilation air per the manual's worksheet; the optional AK4 outside air kits duct extra air in where a home runs tight, and the book recommends two for maximum performance on this series.
Where can it go — and where can't it?
Any ordinary living space that can spare combustion air — built into a wall or a corner, or freestanding under an approved cabinet mantel, directly on a combustible floor. A bedroom only works with a log set rated 10,000 BTU/hr or less, and never a bathroom; Massachusetts bars vent-free heaters from bedrooms and bathrooms entirely and requires a licensed gas fitter and a smoke detector in the area. Keep it out of RVs, high-traffic and drafty spots, note the 4,500 ft elevation caution for pilot outage, and set it on a metal or wood panel over carpet or tile.
How close can a mantel sit above it?
A combustible mantel shelf follows the manual's stepped profile above the hood opening — how far the shelf may project depends on how high it sits, and no part of it may cross that profile. See Figure 7 on page 11 of the installation manual. Noncombustible material may project off the wall above the hood without restriction, and the ceiling stays at least 42" above the opening. You can also send us your mantel depth. We're here to help!
Can I change the white interior later?
Yes — Superior sells refractory stain kits for exactly that. Creamer (ivory), Rust (terra cotta) and Cappuccino (rosy taupe) each come with a roller, tray and one can of stain, and they refinish the white refractory panels in place. The brick pattern itself — Stacked or Herringbone — is the choice you make at purchase.
How does the warranty work if something goes wrong?
Superior warrants the firebox, and The Torch Guys handles it for you — we register the appliance and, if you ever need to claim, we deal with the manufacturer on your behalf rather than handing you a phone number. The body, firebox and barrier carry a 20-year limited warranty. Keep your invoice and the model number; we hold the rest on file.
