Empire Gateway 3500 Wood Stove Size Guide

The Empire Gateway 3500 is rated by the manufacturer to heat 1,000 to 2,700 square feet. Heat output ranges from 17,200 to 57,800 BTU per hour under EPA test conditions, with a maximum heat output of 110,000 BTU per hour on dry cordwood. Average efficiency is 71% HHV / 76% LHV; particulate emissions are 1.6 g/h (lowest in the Gateway series). Maximum burn time is 10 hours on a single load, also the longest in the series. The 3500 is the largest wood stove in the Empire Gateway lineup.

• Large homes (2,000 to 2,700 sq ft). The 3500 is sized for whole-home primary heating in larger homes.
• Great rooms with cathedral ceilings. The peak 110,000 BTU output handles the additional volume of high-ceiling spaces.
• Cold climates (IECC zones 5-7). Drop a 3500 into a 1,800 to 2,400 sq ft home in a cold climate; the lower end of the rated range matches the higher heat-loss factor.
• Overnight 10-hour burns. The largest firebox in the series and 10-hour burn time eliminate middle-of-the-night reloads.
• Longer firewood (22 inch logs). The 3500 firebox is the only Gateway that accepts logs up to 22 inches east-west.
• Lowest emissions and lowest creosote. 1.6 g/h particulate emissions reduces chimney creosote buildup and lowers maintenance frequency.

• Small homes or single-room heating. The 3500's 110,000 BTU peak output will over-heat smaller spaces. Drop to the Gateway 2300 for 1,500 to 2,100 sq ft or the Gateway 1700 for under 1,800 sq ft.
• Homes under 1,000 sq ft. Below the rated minimum heating area; the stove will run hotter than the space needs.
• Tight installation footprints. The cabinet measures 28-1/8 inches wide by 24-5/8 inches deep, the largest in the Gateway series. Confirm the install location accommodates the larger cabinet plus required clearances.
• Cooking applications. The Gateway 3500 is a room heater, not a cook stove.
• Burning anything other than dry cordwood. The Empire warranty explicitly limits approved fuel to cordwood.

• Mild climate (IECC zones 1-3): The 3500 is over-sized for most installations in this band; consider the 2300 unless the home is over 2,200 sq ft.
• Moderate climate (IECC zones 4-5): A strong match for 2,000 to 2,500 sq ft homes; size to the mid-to-upper end of the rated range.
• Cold climate (IECC zones 6-7): Drop to the bottom half of the rated range. 1,500 to 2,000 sq ft homes are well-matched; up to 2,400 sq ft is achievable with a tight, well-insulated home.
• Cathedral ceilings and open multi-story. The 3500 is the typical pick when the home has substantial vertical volume. The optional 130 CFM blower helps distribute warm air to second-floor spaces through stairwells and open landings.

• Non-combustible material: continuous steel sheet minimum 0.015 inch (0.38 mm), or ceramic tiles sealed with grout, cement board, or brick. No R-factor required.
• Front extension (USA): 16 inches measured from the door opening.
• Side extension (USA): 8 inches from each side of the stove.
• Materials per ASTM E136 and UL 763 are considered non-combustible (steel, iron, brick, tile, concrete, slate, glass).
• Non-combustible floors (concrete, brick, slate): no additional floor protection is required.

• Flue outlet diameter: 6 inches.
• Recommended connector pipe: 6 inch diameter, blued or black steel, minimum 24-gauge.
• Approved chimney types: UL 103 HT (2,100°F rated) factory-built, ULC-S629 in Canada, or code-approved masonry chimney with a stainless steel flue liner.
• Minimum chimney height: 12 feet measured from the floor protector.
• 3-2-10 rule: chimney must extend at least 3 feet above the roof penetration and 2 feet higher than any portion of a building within 10 feet horizontally.

• Build on a hot coal bed. Add new wood when the previous load has burned down to bright embers; this keeps secondary combustion lit during the reload.
• Load east-west. Place logs with the sides visible through the glass (parallel to the door).
• Leave space for air circulation. Stack with gaps between logs for combustion air to flow.
• Stay within the EPA loading volume. The 2.88 cu ft EPA loading volume is the maximum recommended fuel load.
• Run the air control wide open after loading. Let the load light off and reach full secondary combustion before stepping down.
• 10-hour overnight burns require a full load. Pack within the EPA loading volume; with hardwood at 18+ percent moisture, a full load reaches the 10-hour burn time.

• Approved fuel: dry cordwood only, at or below 20 percent moisture content.
• Hardwood vs softwood: hardwoods (oak, hickory, maple, beech) burn longer and produce more heat per cord; softwoods burn faster and produce more creosote.
• Seasoning: typical 6 to 12 months under cover with airflow.
• Loading density: EPA loading density 7 to 12 lb/cu ft; maximum heat output density 15 to 20 lb/cu ft on dry cordwood.