10 Best Gas Fireplace Inserts 2025 in the United States

The Duluth Forge Dual Fuel Ventless Gas Fireplace is a versatile insert designed to heat spaces up to 1,500 square feet with a strong 32,000 BTU output. Its standout feature is the ability to use either natural gas or liquid propane, giving flexibility depending on your home's fuel setup. Being ventless means it doesn’t require a chimney or ductwork, making installation easier and less costly, but it needs proper room clearance and good ventilation for safety. The fireplace comes with a stylish antique white mantle and six hand-painted ceramic logs that look realistic, adding a cozy, classic feel to your living space. The remote control with an LCD screen lets you easily switch between manual and thermostat modes to maintain your preferred temperature without hassle.

With an efficiency rating of 99.9%, the unit converts most of the fuel into heat, helping save on energy costs. Safety features include an oxygen depletion sensor that shuts off the unit if air quality drops, along with a reliable battery-assisted Piezo ignition system. The unit is fairly large (45" wide and deep, 15" high), requiring a good amount of space and clearance, which may limit its fit in smaller rooms. Additionally, as a ventless model, monitoring indoor air quality and following installation guidelines carefully is important to avoid ventilation issues. This product is well suited for homeowners seeking an easy-to-install, efficient heating solution that offers fuel flexibility combined with attractive design, while those with smaller rooms or a preference for vented systems might consider other options.

The Duluth Forge Ventless Stainless Outdoor Gas Fireplace Insert offers 24,000 BTUs of heat, which is sufficient to warm a moderate outdoor space comfortably. It operates on natural gas or propane and features a manual control ignition, requiring you to turn it on and adjust the flame yourself without an automatic ignition system. Being ventless, it doesn’t need a chimney or vent pipe, simplifying installation and saving space, which is especially useful for a clean look or limited room.

This insert has a slim, rectangular design that fits easily into existing setups or wall mounts. It uses a stainless steel H-burner with reflective copper glass media, creating a visually appealing flame effect that adds style without the need for logs. Made with high-quality materials and assembled in the USA, it is designed to be fuel-efficient by providing warmth without excessive fuel use.

Since it is vent-free, it may not be suitable for all indoor spaces due to ventilation concerns, and the manual control means less convenience compared to models with remote or electronic ignition. Weighing only 10 pounds, it is relatively easy to handle during installation. If you want a straightforward, stylish outdoor gas insert that offers warmth and ambiance without a complex setup, this model is a solid choice, though manual operation and proper placement for safety and comfort should be considered.

The Duluth Forge Dual Fuel Ventless Gas Fireplace Insert offers a strong 32,000 BTU heating capacity, making it suitable for warming spaces up to 1,500 square feet. Its ventless design means you don’t need a chimney or outside duct, which simplifies installation and saves space. One standout feature is its flexibility to use either natural gas or liquid propane, providing convenience depending on your fuel availability. The included remote control with an LCD screen and manual flame adjustment adds easy, modern operation. Aesthetically, it has a realistic look with six hand-painted ceramic logs, a mesh double door, and a sprayed brick liner that can nicely complement many living rooms. The compact size allows for wall mounting or recess installation, fitting well in various spaces.

The unit also scores high on efficiency at 99.9%, meaning most of the fuel converts to heat, which helps keep energy costs lower. However, being ventless means it relies on indoor air circulation and may not be ideal for tightly sealed rooms without proper ventilation. It requires 7 AAA batteries for the remote, which might need occasional replacement. Also, although it’s advertised as safe with push-button ignition and zero-clearance installation, ventless units can produce some indoor moisture and combustion byproducts, so proper use and room monitoring is important. This insert suits homeowners looking for a powerful, easy-to-install heating solution with dual fuel options and modern controls, especially where adding a chimney is not practical.