Superior VRT3500 Series Vent-Free Gas Firebox
Superior VRT3542 42" Vent-Free Gas Firebox – Radiant Smooth-Faced Design
The Superior VRT3542 is a 42-inch radiant smooth-faced, louverless vent-free gas firebox enclosure designed for compatible listed ANSI Z21.11.2 vent-free gas log systems. It features a large 42" wide × 28" high opening, white stacked refractory interior, included mesh fire screens, and flexible accessory options for built-in new-construction or remodeling projects.
Model
VRT3542
Nominal Size
42"
Opening
42" W × 28" H
Configuration
Firebox Only
Design
Radiant / Louverless
Standard Interior
White Stacked Refractory
Max Heater Input
40,000 BTU/H
Warranty
20-Year Limited
Important: Firebox Enclosure Only
The VRT3542 is not a complete gas fireplace package. The compatible vent-free gas log set, burner, fuel configuration, applicable controls, and required installation components are selected separately.
Large 42" Louverless Vent-Free Fireplace Foundation
The Superior VRT3542 is designed for projects that need the visual presence of a large built-in fireplace while retaining flexibility to select the compatible vent-free gas log system separately.
Its smooth-faced, louverless exterior creates a clean architectural presentation, while the expansive 42" × 28" opening keeps attention focused on the selected log and flame presentation.
The standard white stacked refractory panels on the sides, back, and hearth provide a masonry-inspired appearance inside the firebox.
Superior VRT3542 at a Glance
Brand
Superior Fireplaces
Product Type
Vent-Free Gas Firebox
Fire Screens
Mesh Screens Included
Gas Log System
Sold Separately
Is the Superior VRT3542 Right for Your Project?
Best For
- Projects requiring a large 42" built-in vent-free firebox.
- Homeowners wanting a smooth-faced, louverless fireplace front.
- New-construction and remodeling installations.
- Projects needing a 42" wide × 28" high fireplace opening.
- Buyers wanting a refractory-lined masonry-inspired interior.
- Installations using compatible listed ANSI Z21.11.2 vent-free gas log systems.
- Projects where optional blower capability is desired.
- Installations where optional outside-air or decorative-screen accessories are desired.
- Buyers who want to select the gas-log heater and controls separately.
Consider Another Fireplace If
- You want a complete burner-and-log fireplace package.
- Your project requires direct-vent or conventional vented-fireplace construction.
- Vent-free appliances are not permitted or appropriate for the installation location.
- Your selected heater exceeds 40,000 BTU/H.
- Your gas-log system requires more interior space than the VRT3542 provides.
- Your framing cavity cannot accommodate the required dimensions.
- You need bedroom or bathroom installation.
What Is the Superior VRT3542?
The VRT3542 is the structural firebox enclosure for an approved vent-free gas fireplace installation.
It provides the refractory-lined interior, hearth area, opening, fire screens, and built-in framing platform. The separately selected gas log and burner system determines:
- Fuel type
- Burner configuration
- Control system
- Ignition type
- BTU input
- Flame and log presentation
Do not assign the firebox a standalone heating-output rating. The selected listed unvented decorative room heater provides the heat and must not exceed 40,000 BTU/H.
What Comes With the VRT3542?
Standard Features
- VRT3542 radiant smooth-faced firebox enclosure
- White stacked refractory side panels
- White stacked refractory back panel
- Refractory hearth with ash lip
- Mesh fire screens
- Textured powder-coat exterior finish
Sold Separately / Optional
- Vent-free gas log and burner system
- Applicable gas-log controls
- Decorative twin-pane screen door
- Blower kit
- Outside-air gate and duct kit
- Heat-deflection hood
Gas-log selection rule: Do not order a log set based only on its nominal advertised size. Compare the exact minimum firebox requirements of the gas-log system with the VRT3542 interior dimensions.
VRT3542 Opening & Overall Dimensions
| Nominal Firebox Size |
42" |
| Opening Width |
42" |
| Opening Height |
28" |
| Overall Width |
47-3/4" |
| Overall Height |
41-1/4" |
| Appliance Depth |
20" |
VRT3542 Interior Firebox Dimensions
Use all four interior measurements when determining whether a vent-free gas log heater can physically fit the firebox.
| Interior Front Width |
41" |
| Interior Rear Width |
29-1/4" |
| Interior Depth |
17-3/8" |
| Interior Height |
28" |
Compatibility rule: A gas-log system must fit within the available 41" front width, 29-1/4" rear width, 17-3/8" depth, and 28" height while also meeting its own installation requirements.
VRT3542 Framing Requirements
For the documented parallel installation, Superior lists the following rough-framing dimensions:
| Framing Width |
48-1/4" |
| Framing Height |
44-1/4" |
| Framing Depth |
20-1/2" |
Construction planning: Use Superior's complete installation drawings for corner installations, mantel locations, finishing materials, hearth configurations, and other framing conditions.
Do not scale product photographs or diagrams. Manufacturer diagrams, illustrations, and photographs are not substitutes for the dimensional installation instructions.
Clean, Louverless Fireplace Design
Radiant Smooth-Faced Front
The VRT3542 eliminates prominent louvers around the fireplace opening for a cleaner built-in appearance.
Large Viewing Proportions
The 42" wide × 28" high opening creates a substantial front-facing presentation for the selected gas-log system.
Refractory Interior Options
White Stacked Refractory
The standard VRT3500 configuration uses white stacked refractory on the sides, back, and hearth with an ash lip.
White Herringbone Refractory
A white herringbone refractory configuration is also documented for the VRT3500 Series as an alternative masonry-inspired pattern.
Compatible Vent-Free Heater Requirements
The VRT3542 is designed for compatible listed ANSI Z21.11.2 vent-free gas log sets.
Maximum heater input: 40,000 BTU/H. Do not install a listed unvented decorative room heater that exceeds the manufacturer's stated maximum input.
The exact log and burner model must also satisfy the available interior dimensions, fuel requirements, control requirements, combustion-air provisions, and clearance requirements.
Gas Log Compatibility: What to Check Before Ordering
Front Width
Required by the exact gas-log heater.
Rear Width
Verify against the VRT3542's 29-1/4" interior rear width.
Depth
The VRT3542 provides 17-3/8" interior depth.
Height
The interior height is 28".
Fuel Configuration
Natural gas or propane/LP is determined by the selected heater.
Controls
Ignition and control configuration are determined by the selected burner system.
Nominal size alone does not establish compatibility. Always compare the exact gas-log manufacturer's minimum firebox dimensions with the available VRT3542 interior dimensions.
Compatible Superior Vent-Free Gas Log Styles
The VRT3500 literature identifies several Superior gas-log presentations for consideration. The exact model must still be verified before ordering.
Boulder Mountain
Glow-Ramp Series presentation with rear yellow flames, glowing center area, and ember effect.
Wild Timber
Triple-Flame Series presentation using a multi-burner design and glowing ember bed.
Rugged Stack
Triple-Flame Series log presentation with deep flame pattern and glowing ember bed.
Mossy Oak
Mega-Flame Series presentation with a triple-burner configuration and prominent ember bed.
Giant Timbers
Mega-Flame Series large-log presentation with triple-burner flame configuration.
Optional Accessories
Decorative Twin-Pane Screen Door
Adds a more defined architectural treatment to the fireplace front.
FBK-100 Blower
Optional standard single-speed blower.
FBK-200 Blower
Optional variable-speed blower with wall-mounted control.
Outside-Air Kit
Optional gate-and-duct kit documented for the VRT3500 Series.
Heat-Deflection Hood
Optional for the VRT3542. Using the hood changes applicable mantel and trim clearance requirements.
Optional Blower Planning
The VRT3500 Series supports optional blower equipment.
FBK-100
Standard single-speed blower.
FBK-200
Variable-speed blower with wall-mounted control.
Plan electrical requirements before enclosure. If a blower may be added now or later, review Superior's electrical provisions before the firebox is framed and enclosed.
Heat-Deflection Hood
The heat-deflection hood is optional for the VRT3542.
Clearance effect: Mantel and trim clearance requirements differ depending on whether the optional hood is installed. Use the correct Superior clearance diagram for the final configuration.
Vent-Free Operation & Combustion Air
An approved vent-free gas heater installed in the VRT3542 uses room air for combustion.
The room or communicating spaces must provide adequate combustion and ventilation air according to Superior's instructions and applicable requirements.
Vent-free does not mean air-free. Do not install or operate the heater if the required room-air volume or ventilation provisions cannot be provided.
Installation & Safety Considerations
Approved Heater Only
Use a compatible listed vent-free gas log room heater.
No Solid Fuel
Do not burn wood or other solid fuel in the VRT3542.
No Bedroom Installation
Do not install the firebox in a sleeping room.
No Bathroom Installation
Do not install the firebox in a bathroom.
Combustible Clearances
Maintain all required wall, mantel, trim, flooring, and finishing-material clearances.
Qualified Installation
Gas and optional electrical work should be completed by appropriately qualified tradespeople.
- Keep furniture, curtains, clothing, and combustible materials away from the appliance.
- Avoid high-traffic, windy, or drafty installation locations.
- Do not obstruct the fireplace opening or required airflow.
- Read both the firebox manual and the instructions for the selected gas log system before operation.
Complete Superior VRT3542 Specifications
| Manufacturer |
Superior Fireplaces |
| Series |
VRT3500 |
| Model |
VRT3542 |
| Product Type |
Vent-Free Gas Firebox |
| Configuration |
Radiant Smooth-Faced / Louverless |
| Nominal Size |
42" |
| View Style |
Front View |
| Installation Type |
Built-In |
| Venting |
Vent-Free |
| Opening Width |
42" |
| Opening Height |
28" |
| Overall Width |
47-3/4" |
| Overall Height |
41-1/4" |
| Appliance Depth |
20" |
| Framing Width |
48-1/4" |
| Framing Height |
44-1/4" |
| Framing Depth |
20-1/2" |
| Interior Front Width |
41" |
| Interior Rear Width |
29-1/4" |
| Interior Depth |
17-3/8" |
| Interior Height |
28" |
| Standard Interior |
White Stacked Refractory |
| Alternate Refractory |
White Herringbone Configuration Documented for Series |
| Hearth |
Refractory Hearth with Ash Lip |
| Fire Screens |
Mesh Fire Screens Included |
| Gas Log System |
Sold Separately |
| Approved Heater Type |
Listed ANSI Z21.11.2 Vent-Free Gas Log Set / Unvented Decorative Room Heater |
| Maximum Compatible Heater Input |
40,000 BTU/H |
| Optional Blower |
Yes – FBK-100 / FBK-200 |
| Optional Outside-Air Kit |
Yes |
| Optional Decorative Screen Door |
Yes |
| Heat-Deflection Hood |
Optional |
| Bedroom Installation |
Not Permitted |
| Bathroom Installation |
Not Permitted |
| Solid-Fuel Use |
Not Permitted |
| Warranty |
20-Year Limited Warranty |
Flame Authority Expert Recommendation
Choose the Superior VRT3542 when your project calls for a large 42" built-in vent-free firebox with a clean louverless presentation and the flexibility to select the gas-log heater, fuel configuration, controls, and accessories separately.
Its 42" × 28" opening, 41" interior front width, 29-1/4" rear width, 17-3/8" interior depth, 28" interior height, refractory-lined hearth, included mesh screens, optional blower capability, and 40,000 BTU/H maximum compatible heater input make it well suited to qualifying larger vent-free fireplace projects.
The most important buying step is verifying the selected gas-log heater dimensions, BTU input, framing space, combustible clearances, combustion-air requirements, fuel configuration, accessory plan, and installation location before construction.
Official Manufacturer Resources
Superior VRT3500 Series Product Brochure
Series overview covering VRT3500 firebox designs, refractory options, accessories, and specifications.
Superior Vent-Free Gas Logs Brochure
Manufacturer information covering Superior vent-free gas-log families and available burner presentations.
Superior VRT3500 Series Smart Sheet
Quick-reference features, sizing, refractory, accessory, and technical information.
Superior VRT3500 Series Installation & Operation Manual
Manufacturer installation, framing, clearances, combustion-air, gas-line, electrical, operating, and safety requirements.
Superior VRT3500 Series Specification Sheet
Manufacturer dimensions, framing measurements, interior dimensions, configuration data, and technical specifications.
Superior VRT3542 FAQs
What is the Superior VRT3542?
The Superior VRT3542 is a 42-inch radiant smooth-faced vent-free gas firebox enclosure designed to house a compatible listed vent-free gas-log heater sold separately.
Does the Superior VRT3542 include gas logs?
No. The VRT3542 is the firebox enclosure; the compatible vent-free gas log, burner, fuel configuration, and applicable controls are sold separately.
What are the framing dimensions for the Superior VRT3542?
The documented parallel framing dimensions are 48-1/4" W × 44-1/4" H × 20-1/2" D.
What are the overall dimensions of the VRT3542?
The firebox measures approximately 47-3/4" wide × 41-1/4" high × 20" deep, with a 42" W × 28" H opening.
What are the interior dimensions of the VRT3542?
The interior measures 41" wide at the front, 29-1/4" wide at the rear, 17-3/8" deep, and 28" high.
What gas logs are compatible with the VRT3542?
The VRT3500 Series is designed for compatible listed ANSI Z21.11.2 vent-free gas log systems. Verify the exact heater model against all available interior dimensions before ordering.
What size gas logs fit the Superior VRT3542?
Do not choose by nominal size alone. Compare the gas-log heater's exact minimum firebox requirements with the VRT3542's 41" front width, 29-1/4" rear width, 17-3/8" depth, and 28" height.
What is the BTU rating of the Superior VRT3542?
The firebox itself does not have one universal heating-output rating. The separately selected listed vent-free heater must not exceed 40,000 BTU/H.
Does the VRT3542 require a chimney?
No conventional chimney is used with an approved vent-free heater installation, but combustion-air, ventilation, clearance, and installation requirements still apply.
Can wood be burned in the VRT3542?
No. Do not burn wood, solid fuel, or other combustible materials in the VRT3542.
Does the VRT3542 come with a blower?
No. Blower equipment is optional. Superior documents the FBK-100 single-speed and FBK-200 variable-speed blower options.
Can a blower be added later?
Yes, but the required electrical provisions should be planned before the firebox is framed and enclosed if a blower could be added later.
Does the VRT3542 include fireplace screens?
Yes. Mesh fire screens are included with the firebox.
What refractory liner comes with the VRT3542?
The standard configuration includes white stacked refractory panels on the sides, back, and hearth. A white herringbone configuration is also documented for the series.
Is the VRT3542 heat-deflection hood required?
No. The heat-deflection hood is optional for the VRT3542, but its use changes applicable mantel and trim clearance requirements.
Can the VRT3542 be installed in a bedroom or bathroom?
No. Superior's installation instructions state that these built-in vent-free fireboxes must not be installed in a sleeping room or bathroom.
Does a vent-free fireplace still require combustion air?
Yes. The installed vent-free heater uses room air, so the installation must provide the required combustion and ventilation air.
What optional accessories are available?
Documented options include blower kits, an outside-air kit, decorative screen door, optional heat-deflection hood, and compatible vent-free gas-log systems.
What warranty does the Superior VRT3542 have?
The VRT3500 Series is listed with a 20-year limited warranty. Separately purchased gas logs, burners, controls, and accessories are subject to their own warranty terms.
Before You Order
Confirm Before Purchase
- You specifically need the Superior VRT3542.
- Your project can accommodate the 48-1/4" W × 44-1/4" H × 20-1/2" D framing requirements.
- You understand that the product is a firebox enclosure only.
- You have identified a compatible listed vent-free gas-log heater.
- The selected heater does not exceed 40,000 BTU/H.
- The heater fits within the 41" front width, 29-1/4" rear width, 17-3/8" depth, and 28" height.
- You can meet all mantel, wall, trim, flooring, and finishing-material clearances.
- The room provides adequate combustion and ventilation air.
- The installation is not in a sleeping room or bathroom.
- You have planned any optional blower electrical requirements before enclosure.
- You have selected the intended refractory and accessory configuration.
Do Not Assume
- That the VRT3542 includes gas logs or a burner.
- That every 42" gas-log system will fit.
- That nominal size alone establishes compatibility.
- That the firebox itself produces 40,000 BTU/H.
- That vent-free operation eliminates combustion-air requirements.
- That wood or solid fuel can be burned inside the firebox.
- That bedroom or bathroom installation is permitted.
- That the optional hood has no effect on mantel or trim clearances.
- That a blower can always be added later without electrical planning.
- That product photographs or diagrams can be used as scaled construction drawings.
Final planning check: Use the Superior VRT3500 Installation & Operation Manual, Specification Sheet, Smart Sheet, and documentation for the exact selected gas-log heater to verify framing, heater compatibility, BTU input, combustion air, fuel, controls, clearances, accessory requirements, and final installation before construction.
