Vent-free gas fireplace · Duluth Forge

Duluth Forge DF300L Dual-Fuel Vent-Free Gas Fireplace

Vent-free gas fireplace, up to 1,400 sq ft, 26,000 BTU/h

Heats up to (maker)
1,400 sq ft
Heat output (maker)
26,000 BTU/h
Efficiency (maker)
99.9%
Fuel
dual fuel
Venting
ventless
Thermostat
thermostat
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In short

Built for supplemental heat for one room.

Wins
26,000 BTU/h.
Gives ground
Adds moisture to the room.
Suits
Supplemental heat for one room.

Updated October 2026

What you get

The Duluth Forge DF300L Dual-Fuel Vent-Free Gas Fireplace is a vent-free gas fireplace that its maker rates at 26,000 BTU per hour and says heats up to 1,400 square feet.

Treat the 1,400 square feet as the maker's best case for an open, reasonably insulated space, and check it against your room before choosing.

At full fire it burns about 25 cubic feet of natural gas or about 0.28 gallons of propane an hour (its 26,000 BTU/h divided by EIA's heat content for each fuel).

Vent-free means no pipe: combustion air comes from the room and the exhaust stays in it. The manual's room-size and altitude limits and its oxygen-depletion sensor are part of using it safely; check local code first. Vent-free vs direct-vent.

Fuel, per the listing: dual fuel. Never connect a gas heater to a fuel it isn't set for.

Ignition: Piezo ignition.

Also on the listing: overall dimensions of 7.84 in (D) x 27.95 in (W) x 18.05 in (H), a shipping or unit weight of 31 lb and ceramic construction.

The figures, from the maker

Each figure is the maker's or the listing's own, with its source marked. A figure the maker doesn't give is shown as not stated.

Model numberDF300LRetailer
PowerGas PoweredRetailer
Dimensions (seller)7.84"D x 27.95"W x 18.05"HRetailer
MaterialCeramicRetailer
Mounting / installationBuilt In,Wall MountRetailer
Heat output (maker)26,000 BTU/hRetailer
Features (seller)Dual Fuel Technology, Thermostat ControlRetailer
Model nameDF300LRetailer
Product weight31 lbRetailer
Heats up to (maker)1,400 sq ftRetailer
Efficiency (maker)99.9%Retailer
VentingventlessRetailer
Fueldual fuelRetailer
ThermostatthermostatRetailer
IgnitionPiezo ignitionRetailer

Is it the right heater for the room?

Pick it when

  • Supplemental heat for one room
  • Homes with gas or propane
  • Heat without electricity

Pass on it when

  • Bedrooms and small rooms the manual excludes
  • Places where local code bans vent-free heaters

Where it wins, where it gives ground

Wins

  • 26,000 BTU/h
  • No chimney needed
  • dual fuel
  • Works in a power cut

Gives ground

  • Adds moisture to the room
  • Restricted by some local codes
  • Needs a gas line

Know before you install

  • Figures are the maker's own and are rated in the maker's conditions. Installation, venting, chimney, gas and electrical work follow the manual and local code, carried out by a qualified installer.

Heaters to weigh against it

Other gas stoves, fireplaces and inserts in the same heat range

Every gas stoves, fireplaces and inserts on one chart · All Duluth Forge models listed

Buying this model

The button opens this exact model's listing. Prices and stock change, and installation parts are usually sold separately; check the box contents and the manual's venting list before you order.

Prices change often; the button shows today's price.

Each button opens this exact model. We may earn a commission on tracked links; it never changes what we publish. Disclosure

Questions about this model

How much gas does the Duluth Forge DF300L Dual-Fuel Vent-Free Gas Fireplace use?
At full fire, about 25 cubic feet of natural gas or about 0.28 gallons of propane an hour, from its 26,000 BTU/h rating and EIA's heat contents; lower settings use less.
Does the Duluth Forge DF300L Dual-Fuel Vent-Free Gas Fireplace need a vent or chimney?
No: it's vent-free. Its manual sets the minimum room size and other limits, and some local codes restrict vent-free heaters.

Bottom line

Built for supplemental heat for one room.