Regency Atmosphere Gas Insert

Right buyer

Owners of an existing wood-burning masonry fireplace — or an approved factory-built fireplace — who want to convert it into a sealed, thermostat-controlled gas heater without rebuilding the wall. A gas insert slides into the existing firebox, runs two aluminum liners up the existing chimney, and turns an open fireplace that loses room air up the flue into a closed direct-vent appliance that draws combustion air from outside. The four sizes exist so the unit is chosen by the opening you already have, not the other way around: measure the firebox width, height, depth, and rear width first, then pick the largest size whose fit table (under Where it can go) clears those numbers.

Buyers who want the realism features as standard equipment. The Infusion burner is integrated into the log set so flames wrap from inside the logs; every size includes the variable-speed blower, the Proflame II full-function remote, ceramic glass, and the Invisimesh screen built into each faceplate and trim. On most competing inserts the blower or remote is an extra line on the invoice; here the realistic extras are the base unit.

Buyers who want at-order configurability on two real design choices. Log set: Oak, Birch, or Driftwood on all four sizes, plus a High-Definition Oak set with glowing center logs on the 29 and the 33. Faceplate and trim: 3-Sided Finishing Trim, 4-Sided Finishing Trim, Flush 3-Sided Faceplate, Flush 4-Sided Faceplate, or Regular 3-Sided Faceplate, each sized to its model. The combination changes the appliance's visual character from a minimal trim line to a full traditional front, and Premium and Traditional surrounds sold separately extend it further.

Buyers in power-outage-prone areas who still want electronic ignition. The LE models pair electronic ignition with battery backup — Regency's "Power's Out, Heat's On" system — so the burner still lights and heats during an outage; only the blower and ember lights wait for power to return.

Buyers heating with propane. Each size converts with a model-specific LP kit installed by the licensed gas fitter. Note the honest derates: the 27 runs 22,000 BTU/hr maximum on LP and the 33 runs 36,500, while the 25 and the 29 hold their natural-gas maximums on propane.

Wrong buyer

Not for buyers without an existing fireplace. An insert needs a masonry or approved factory-built firebox and a chimney to host its liners. Building a fireplace into a framed wall from scratch is a direct-vent gas fireplace's job — a different appliance category — not an insert's.

Not for openings smaller than the published minimums. The 25 with the Regular faceplate still needs 25" wide × 17" high × 15" deep with a 15" rear width; flush faceplates and trims need slightly more on every size. If the firebox measures under those figures, no size in this collection fits — measure before falling for the photos.

Not for buyers who want wood heat. If the goal is to keep burning cordwood with real heating performance, that is a wood insert's job — look at the Osburn Matrix 2700 or Osburn 3500 wood inserts instead. Once a fireplace is converted to a gas insert it carries a permanent label and cannot burn wood again unless fully restored and re-approved by the local authority.

Not for buyers who want a standing pilot. All four sizes on this page are electronic-ignition LE units. Regency builds the 29 as the Gi29LU with a standing pilot, an on/off remote, and a lower price; buyers who specifically want a continuously burning pilot should ask about that model rather than buy an LE.

Not for B-vent or vent-free expectations. These are sealed direct-vent appliances certified as complete systems with specific liner-and-cap combinations. They cannot share a flue with any other appliance, cannot run unvented, and using venting components not on Regency's approved list voids both certification and warranty.

Standard on every size

Each size's heat numbers are tabled under "How it actually performs" below, and its space and clearance requirements under "Where it can go."

The Atmosphere inserts install into an existing wood-burning masonry fireplace, or an approved factory-built fireplace, with a structurally sound chimney that can host the liner run. The chimney must serve this appliance alone — never a flue shared with another appliance — and the existing firebox and flue must be cleaned before installation. The flue damper is blocked open or removed. Once installed, the host fireplace is permanently converted: the installer fixes a label inside the firebox stating it can no longer burn wood or solid fuel unless fully restored and re-approved by the authority having jurisdiction.

Each size's fit numbers are below. The opening figures are for the Regular faceplate — the smallest-opening configuration. The front you configure changes the requirement: flush faceplates and finishing trims need roughly 1–1.5" more width and height and 1–1.25" more depth on every size (for example, the 29 needs 28-7/16" × 20-1/4" with the Regular faceplate but 30" × 21-1/16" with the Flush or Trim fronts), and adding a backing plate raises the figures again. Each spec sheet publishes the full opening-by-faceplate table — have the installer measure the firebox, including rear width and the lintel-bar depth, against the exact configuration before ordering.

25-Inch — Gi25LE

27-Inch — Gi27LE

29-Inch — Gi29LE

33-Inch — Gi33LE

Hearth and floor

The hearth values above follow a pattern worth knowing for flooring plans: the 29 and the 33 require a non-combustible hearth at least 36" wide × 12" deep unless the unit is raised off the floor by the stated height, while on the 25 and the 27 a hearth is recommended but not required — combustible flooring brought up to the appliance must sit level with or below the appliance base, and no combustible material is permitted underneath it. Whatever the requirement, the hearth surface in front of any of these gets genuinely hot; Regency's own warning is not to use it as a seat or a shelf.

Mantels

Combustible mantel height is governed by a graduated chart in each spec sheet — the deeper the mantel projects, the higher it must sit. The values above are the minimums at a full 12-inch mantel depth, with and without each model's optional mantel deflector; shallower mantels may sit lower per the chart. A non-combustible mantel over metal-stud framing may sit lower still, but never less than 6" above the top of the fireplace opening. Confirm the exact mantel geometry against the model's chart before finalizing the surround.

Refacing the fireplace front

Within the zone around the insert, only non-combustible facing — tile, stone, brick, cement board over steel studs — is permitted, and any gap between the masonry firebox face and the new facing must be sealed so heat cannot travel behind it. The spec sheets publish the non-combustible zone per size: 6" horizontal and 20" vertical from the opening on the 25, 8" and 20" on the 27, 8" and 23" on the 29, and 8" and 25-1/4" on the 33. Combustible facing and trim are permitted outside that zone. The configured faceplate or finishing trim forms the finished edge between the insert and the surround.

Venting

Each insert vents with two co-linear aluminum flex liners running the full, continuous height of the existing chimney — one combustion-air intake, one exhaust — terminated with a listed cap and flashing, at the sizes and run lengths in the fit tables above. The 25's 2" intake × 3" exhaust alternative exists for a specific situation: it lets the 25 reline a 6" round Class A wood-stove chimney that a 3" + 3" pair will not fit. Each appliance is certified as a complete system only with the listed Regency or DuraVent caps and liners — substituting unlisted venting voids both certification and warranty. The vent restrictor must be set per the height chart for the liner run, a detail worth confirming on the installer's checklist.

For masonry chimneys where a vertical termination is impossible, the horizontal co-linear kits in the tables exit through the back of the masonry chimney: the 29's is approved on natural gas only, with a 9–10 ft rise and 18" maximum horizontal run, while the 33's is approved on both NG and LP. The 25 and the 27 vent vertically.

Gas and electrical

A 3/8" NPT gas line is brought to the unit's connection point — through a drilled access hole of 1-1/2" or less in a factory-built firebox, plugged with non-combustible insulation afterward. Only a licensed gas professional may make the gas connection, and in Massachusetts installation and repair must be performed by a licensed plumber or gas fitter. The blower, ember lighting, and WiFi control need 110V at the fireplace: either a cord to a nearby outlet or the optional hardwire kit with armored cable for a finished, cordless installation.

Code compliance

The local authority having jurisdiction approves what is permitted at your address; the manufacturer's listing covers what the appliance is approved for. Where no local code applies, installation follows the National Fuel Gas Code ANSI Z223.1 in the USA or CSA B149.1 in Canada. A permit and a licensed gas installer are the normal path, and frequently required by code or insurance — plan both into the project, not after it.

California Proposition 65

This product can expose you to chemicals including carbon monoxide, which is known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to www.P65warnings.ca.gov.

Ships with the insert

• Atmosphere insert body in the configured size — 25-inch Gi25LE, 27-inch Gi27LE, 29-inch Gi29LE, or 33-inch Gi33LE — with Infusion burner, ceramic glass, and 30° vent termination collars (3" intake × 3" exhaust; 3" × 4" on the 33)
• Electronic ignition system with battery backup
• Variable-speed blower, factory-installed
• Proflame II GTMF remote control with thermostat function
• Configured at order with required log set — Oak, Birch, or Driftwood on all sizes; High-Definition Oak available on the 29 and the 33. On the 29 and 33, Oak and Birch sets include the required log grate and ember media, and the Driftwood set includes the required lava embers and one crushed-glass pack (Coal Black supplied as the default; confirm Iceberg or Ginger at order, same price)
• Configured at order with required faceplate or finishing trim — 3-Sided Finishing Trim, 4-Sided Finishing Trim, Flush 3-Sided Faceplate, Flush 4-Sided Faceplate, or Regular 3-Sided Faceplate — each with the Invisimesh safety screen built in
• Black Steel inner panels included as the standard interior on the 29 and the 33 (interior panels are required on these two sizes)
• Owner's installation and operation manual and product documentation

Sold separately

• Venting — required, sized to the chimney: Regency co-linear vertical termination cap and flashing (946-529 for the 25/27/29; 946-588 for the 33) with 3" × 35 ft flex liners (948-305) and, for the 33, a 4" × 35 ft exhaust liner (948-336); the 25's 2" × 3" alternative uses the 946-582 cap with a 2" × 35 ft liner (948-316); approved DuraVent alternatives include the 46DVA-CL33 / 46DVA-CL34 co-linear kits, 46DVA-VC and 46DVA-VCH caps, 46DVA-GK adaptor, and 46DVA-34CLTA conversion; horizontal co-linear kits 46DVA-HCL33 (29, NG only) and 46DVA-HCL34 (33)
• LP conversion kits, installed by the gas fitter — 262-969 (25, serial 601000403+), 550-969 (27), 311-969 (29), 391-969 (33)
• Interior panel upgrades, each replacing the standard interior — Rustic Brown or Volcanic Black brick (262-901/262-905 for the 25; 550-901/550-905 for the 27; 311-901/311-905 for the 29; 391-901/391-905 for the 33), Herringbone brick (262-903 / 550-903 / 311-903 / 391-903), Castle Stone Grey (311-904, 29 only), reflective black glass (550-906 for the 27; 311-906 for the 29; 391-906 for the 33)
• Premium faceplate surrounds for the Regular 3-Sided faceplate — Black, Grey, White, Sunset Bronze, Brushed Nickel (550-920 to 550-924 for the 25/27; 311-920 to 311-924 for the 29; 391-920 to 391-924 for the 33)
• Traditional surrounds for the Flush 3-Sided faceplate — Black and Brushed Antique Copper (550-927/550-928; 311-927/311-928; 391-927/391-928)
• Backing plates for oversized or irregular openings — 3-Sided Oversize (262-936 / 550-936 / 311-936 / 391-936) and made-to-measure Custom 3- or 4-Sided plates per Regency's order form
• Custom flush faceplates, special order with required separate mesh screen — custom 3- or 4-sided plus the model's mesh screen part (262-916 / 550-916 / 311-916 / 391-916)
• Adjustable hearth trim for raised installations (262-941 for the 25/27; 311-941 for the 29; 391-941 for the 33) and mantel deflectors that reduce mantel clearance (262-940 / 550-940 / 311-940 / 391-940)
• Gas insert hardwire kit with armored cable for a cordless 110V connection (946-854) and WiFi app-control kit for the Proflame Connect Plus app (946-799)
• Crushed-glass media in Coal Black, Iceberg, or Ginger (946-780 / 946-781 / 946-779) and lava embers (946-783) — replacement or alternate-color media for Driftwood fire beds
• BTU reduction orifice for the 29 at 2,000–4,500 ft altitude (311-980)
• Installation by a licensed gas professional, with permit per the local authority — required for code, certification, and warranty; in Massachusetts, a licensed plumber or gas fitter

Gas-insert ratings are inputs: the BTU figure is fuel burned per hour, not heat delivered to the room. The honest arithmetic multiplies input by fireplace efficiency. At maximum input on natural gas, delivered heat lands at roughly 13,000 BTU/hr on the 25 (20,500 × 63.6%), 15,900 on the 27, 20,100 on the 29, and 24,800 on the 33. That is the number to weigh against the room — and it is real, continuous, thermostat-controlled heat, not the transient peak of a wood fire.

One table per size. "Maximum input" is the most gas the burner can use in an hour — the size of the fire. "Turndown" is how low the flame can idle on a mild evening. Efficiency is the certified share of that gas that becomes heat in your room.

25-Inch — Gi25LE

27-Inch — Gi27LE

29-Inch — Gi29LE

33-Inch — Gi33LE

The modulation range is what daily life feels like. Each burner turns down — to 14,500 BTU/hr on the 25, 17,000 on the 27 and the 29, 20,500 on the 33 — and the Proflame II remote's thermostat mode cycles and modulates the flame to hold a set room temperature. In practice the larger units' higher turndown floors matter: a 33 in a modest, well-insulated room will cycle off and on rather than idle low, while the 25's 14,500 floor lets it run long and low in a small space. Match the size to the room as well as to the opening.

The CSA P.4.1 fireplace-efficiency ratings — 63.6% on the 25 up to 64.30% on the 33 — are the regulated, cross-brand comparable numbers, and they sit in the ordinary range for traditional-style log inserts rather than the top of it. Regency's separate steady-state efficiency table reads higher (65.12% on the 25 up to 71.45% on the 29) because it measures sustained operation differently. Buyers ranking efficiency above flame realism should know the wider Regency lineup before deciding: the Liberty LRI4E and LRI6E carry FE ratings around 70%, and the Energy E33 posts an 84% steady-state figure with a more utilitarian presentation — sold through Regency dealers rather than here.

What the Atmosphere line trades that efficiency margin for is the fire itself. The Infusion burner sits inside the log set, so flames climb through and around the logs instead of rising in a curtain behind them — the architecture conventional pan burners cannot reproduce. The 29 and the 33 add ember-bed lighting under the fire bed, which keeps a glowing-coal presence when the burner is off or modulated low. The glass viewing areas — 221 sq in on the 25, 243 on the 27, 319 on the 29, 504 on the 33 — are large for each opening class, and the Invisimesh screen is fine enough that the certified barrier reads as near-invisible at viewing distance.

On propane, the 25 and the 29 hold their natural-gas maximum inputs; the 27 drops to 22,000 BTU/hr and the 33 to 36,500. The 29 additionally derates on natural gas at altitude — 30,500 BTU/hr maximum from 2,000 to 4,500 ft, with a derating orifice part for the application. None of these are defects; they are the published physics of orifice sizing, and they belong in the sizing decision rather than in a post-install surprise.

During a power outage the battery-backup ignition keeps the burner lighting and heating. Expect reduced comfort rather than none: the blower that pushes convective heat into the room is a 110V device, so outage heat is radiant and natural-convection only, and the ember lights are dark until power returns.

Efficiency is mid-pack, not class-leading. FE ratings of 63.6–64.3% are ordinary for traditional log inserts. Regency's own Liberty LRI4E (70.27% FE) and LRI6E (70.37% FE) deliver meaningfully more heat per therm, and the Energy E33 posts an 84% steady-state efficiency. The Atmosphere premium buys the Infusion flame and the configurability, not the efficiency crown — buyers heating primarily on dollars-per-BTU should weigh the Liberty line first.

Ember-bed lighting skips the 25 and the 27. The glowing-ember LED effect is standard on the 29 and the 33 only. A 25 or a 27 shows its log set by flame light alone, and the difference is visible in the off-season when the burner is dark.

The turndown floor rises with size. A 33 cannot burn lower than 20,500 BTU/hr in. In a small, tight room the thermostat will cycle the big burner on and off rather than hold a gentle low flame — fine functionally, less serene visually. If the room is modest, the smaller insert with the lower floor is the better fire, not just the cheaper one.

Faceplate choice changes the required opening. The minimum-opening figures most buyers quote are for the Regular faceplate; flush faceplates and trims need roughly an inch or more in width, height, and depth on every size, and backing plates add again. A firebox that fits one configuration can fail another — the installer must measure against the exact front being ordered.

The Driftwood fire bed carries extra required media. On the 29 and the 33 the contemporary Driftwood set requires lava embers plus a crushed-glass pack; both are included in the configured price here, but glass color must be confirmed at order and replacement media is a consumable line later. Oak and Birch on those sizes require the log grate, also included in the configured price. The High-Definition Oak set carries no grate requirement in the price book; its glowing center logs are built into the set itself.

Premium finishes carry short warranty coverage. Under Regency's current gas warranty, brushed nickel, antique copper, and black chrome faceplates and surrounds, and the reflective black-glass panels, are covered for one year — and the policy explicitly expects plated finishes to change color with heating cycles. Choose the upgrade finishes for the look with that understanding, not as lifetime hardware.

Electrical work is part of the install. The blower, ember lights, and WiFi kit need 110V inside or beside the firebox. If there is no outlet, the hardwire kit and an electrician join the budget. The battery backup covers ignition in an outage, not the blower.

Propane and altitude shave the numbers. The 27 on LP: 22,000 BTU/hr maximum, not 25,000. The 33 on LP: 36,500, not 38,500. The 29 above 2,000 ft: 30,500 on NG. The 25's LP kit applies only to serial 601000403 and up. Quote the configuration's real figure, not the brochure's.

Horizontal venting is narrow. Only the 29 and the 33 list horizontal co-linear kits, only through a masonry chimney's back wall, and the 29's is natural-gas-only with a tight 9–10 ft rise and 18" maximum horizontal. If the chimney cannot take a vertical liner pair, confirm the horizontal geometry early — it eliminates configurations.

The conversion is one-way. Once the insert is installed, the host fireplace is labeled and cannot legally burn wood again unless the original parts are restored and the fireplace is re-approved by the local authority. Buyers ambivalent between gas convenience and wood ritual should settle that question before this purchase, not after.

No heat ducting. Unlike some zero-clearance fireplaces, these inserts do not offer a ducted heat-distribution option. The heat serves the room the fireplace is in; whole-home distribution remains the furnace's job.

First burns. The first several hours of operation cure the high-temperature paint and burn off manufacturing residues. Expect odor and a light film on the inside of the glass; ventilate the room, run the unit at a high setting for the initial burns, and clean the glass once cool. The smell is temporary and normal.

Daily operation. The Proflame II remote handles on/off, flame height, blower speed, and thermostat mode; in thermostat mode the unit modulates and cycles to hold the set temperature like any other heating appliance. The optional WiFi kit moves the same controls to the Proflame Connect Plus app. There is no pilot consuming gas between fires — electronic ignition lights on demand. An optional continuous-pilot (CPI) mode is selectable on the remote; its on-demand pilot shuts itself off automatically after seven full days without a call for heat, and one off-on press relights it.

Blower behavior. In thermostat mode the fan waits about five minutes after the burner lights before starting, and runs on for about twelve minutes after shutoff while the unit cools; in manual mode it responds immediately from the remote. That delay and after-run are the design working, not a fault. Keep the blower intake free of dust and pet hair; a vacuum at the louvers each season keeps it quiet.

Power outages. The battery-backup ignition lights the burner with the power out, delivering radiant and natural-convection heat without the blower. Keep fresh batteries in the backup pack at the start of each heating season — a dead backup discovered during a winter outage is the predictable failure mode.

Glass and screen. Clean the ceramic glass only when cool, with a gas-fireplace glass cleaner — never abrasives, and never household ammonia cleaners on hot glass. A white film developing over time is mineral deposition from combustion and normal; clean it before it bakes in. The Invisimesh barrier screen stays in place whenever the fireplace operates: the glass behind it runs hot enough to burn skin on contact, and the screen is the certified safeguard, particularly with children or pets in the house.

Log and media placement. The Infusion burner only produces its flame pattern — and only burns cleanly — with the logs, embers, and media placed exactly per the manual's diagrams. Improvised arrangements cause sooting, impingement, and service calls. After any cleaning, restore the placement to the diagram, not to memory.

Annual service. Once a year, a licensed gas technician should clean the burner and pilot assembly, verify the flame picture, check gas pressures, inspect and reseal glass gasketing as needed, confirm the venting is intact and unobstructed from appliance to cap, and test the safety systems. Annual maintenance is a stated condition of the warranty — keep the receipts, because FPI can ask for maintenance records with a claim.

What never goes in the firebox. Nothing. No wood, no paper, no decorative objects beyond the listed Regency media for the configured fire bed. This is a sealed gas appliance, not a stove with a gas option — the converted fireplace's label says the same thing in regulatory language.

Vent checks. Glance at the termination cap each fall: bird nests, leaf packs, and snow drifts over the cap are the common airflow failures. The liner run is sealed and passive, but the cap lives outdoors and earns a yearly look.

The Atmosphere inserts are covered by the FPI / Regency Limited Lifetime Warranty for indoor gas products (current policy effective August 1, 2025), extended to the original purchaser with the appliance in its original place of installation. The warranty is non-transferable. Coverage is parts-and-labor by component as below, with labor paid at subsidized, pre-determined rates — dealers may charge travel and time beyond the subsidy, and dealer travel costs are not covered.

Coverage by component

Conditions worth knowing before a claim, not after: the appliance must be installed per the manual and all codes by a qualified installer; the original purchaser is responsible for documented annual maintenance, and FPI may request the records; claims are submitted by the servicing dealer with the bill of sale; FPI may require field inspection before authorizing a claim; replacement appliances are limited to one per warranty term, and if no suitable replacement exists FPI may refund 50% of the verified purchase price of the appliance and its FPI accessories. Plated finishes are expected to change color with heating cycles — color change, fingerprints, and abrasive-cleaner damage are excluded, as are lava rock, glowing embers, batteries, gasketing, and damage from improper venting, unqualified installation, corrosive environments, misuse, or unapproved third-party components.

Warranty service runs through the authorized selling dealer, with FPI (Fireplace Products US, Inc. for US customers) as warrantor — Kaminos supports buyers through purchase, and final warranty approval rests with FPI. Regency registration is requested within 90 days of purchase. Replacement log sets, panels, media, glass, remotes, blowers, and venting components are openly available through the Regency dealer and parts network.

Coverage applies to defects in manufacture or factory-assembled components; component coverage varies with the options purchased.

Coverage details can change by component and warranty revision; the current FPI/Regency written warranty controls.