Sizing & Specs
BTUs, dimensions, and matching the right size unit to your room.
btu room sizing
- How many BTUs per square foot do I need to heat a room with a fireplace?
- What is a BTU and what does it mean on a fireplace spec sheet?
- How many square feet will a 30,000 BTU gas fireplace heat?
- Does ceiling height matter when sizing a fireplace for a room?
- Do climate, insulation, and windows change what size fireplace I need?
- Can a gas fireplace be too big for a room?
- What happens if my gas fireplace is undersized for the space?
- How many BTUs does a typical gas fireplace put out?
- What does the 'heats up to X square feet' rating on a fireplace spec sheet really mean?
- What is zone heating and how does it change what size fireplace I need?
- Can one gas fireplace or wood stove heat an entire house?
- Does high altitude reduce a gas fireplace's BTU output?
- Can I turn a gas fireplace's heat down if it's too much, and by how much?
gas log sizing
- How many BTUs do gas logs put out?
- What size gas logs do I need for a 36-inch fireplace?
- When a gas log set is called 24 inches, what does that measurement actually refer to?
- What do front width and rear width mean on a gas log sizing chart?
- Can gas logs be too big for my firebox?
- Is it a problem if gas logs are too small for my fireplace?
- How much clearance do gas logs need from the firebox walls?
- What is the minimum firebox depth for a vented gas log set?
- Do vented and ventless gas logs of the same size fit the same fireboxes?
- Does the burner size or the log size determine whether a gas log set fits?
- Are gas log BTU ratings different for propane versus natural gas?
efficiency ratings
measuring firebox
- How do I measure my fireplace for a gas insert?
- How do I measure my firebox for gas logs?
- My firebox is narrower at the back than the front — which width do I use?
- How do I measure firebox depth correctly?
- Do I measure firebox height to the damper or to the top of the opening?
- How can I tell if I have a masonry or prefab fireplace when measuring for an insert or logs?
- How do I measure a fireplace with an arched opening?
- How do I measure for a corner fireplace?
- How do I measure my fireplace opening for glass doors?
- What measurements does a fireplace dealer need before quoting an insert or log set?
ventless sizing
insert sizing
- What size gas insert will fit my existing fireplace?
- What are the minimum firebox dimensions for a gas insert — will one fit a small fireplace?
- Can a gas insert go into a shallow firebox?
- Will an insert fit a prefab zero-clearance fireplace?
- How much smaller than my fireplace opening will an insert's viewing window be?
- What is the surround or flashing panel on an insert and how is it sized?
- How far does a fireplace insert stick out onto the hearth?
- How do I size a wood-burning insert to my firebox?
- Do fireplace inserts come in different depths?
standard dimensions
- What are standard gas fireplace dimensions?
- What is a standard fireplace opening size?
- What does a fireplace's listed size like '42-inch' actually measure — viewing area or frame?
- What is the rough opening or framing size for a built-in direct vent fireplace?
- How much wall depth does a built-in gas fireplace need — will it fit in a 2x4 wall?
linear sizing
viewing vs heating
see-through sizing
weight support
gas line sizing
- What size gas line does a gas fireplace need?
- Is a 1/2-inch gas line big enough for a gas fireplace?
- How do I know if my existing gas line can handle a new fireplace?
- Does the length of the gas line run change what pipe size I need?
- How many BTUs can a 3/4-inch gas line supply?
- What gas pressure does a fireplace need for natural gas versus propane?
- Can a fireplace tee off the gas line that already feeds my furnace or range?
- Can my gas meter or propane regulator handle adding a fireplace?
- What size gas line does an outdoor fire pit or outdoor fireplace need?
fuel specs
electrical requirements
- Does a gas fireplace need electricity, and will it still work in a power outage?
- Do I need an electrical outlet inside or near the fireplace for the blower and ignition?
- Can I plug an electric fireplace into a regular 120V outlet or does it need a dedicated circuit?
- How many watts and amps does an electric fireplace draw?
- Are there 240V electric fireplaces, and when do you need one?
- Can I use an extension cord or power strip with an electric fireplace?
- Does a wood stove or wood-burning insert need an electrical outlet?
electric specs
- How many BTUs of heat does an electric fireplace put out?
- How many square feet can an electric fireplace actually heat?
- Does the size of an electric fireplace change its heat output?
- What sizes do electric fireplace inserts come in?
- What size electric log set fits my existing fireplace?
- How much wall depth does a recessed electric fireplace need?
blower specs
glass types
ember bed media
- What is the ember bed on a gas log set and how big should it be?
- Can I add extra embers or sand to my gas logs?
- Why do propane log sets use vermiculite instead of sand?
- What size fire glass do I need for my burner?
- How much fire glass does it take to fill a fire pit?
- Can I use fire glass instead of logs in an indoor gas fireplace?
wood stove sizing
- What size wood stove do I need for my square footage?
- What does firebox cubic feet mean on a wood stove?
- What length firewood fits in a wood stove — how is log capacity measured?
- Does a bigger firebox mean longer burn times on a wood stove?
- Why do wood stove BTU ratings vary so much between brands?
- Does an open wood-burning fireplace have a BTU rating?
clearance specs
venting flue size
fire pit sizing
- How many BTUs is a typical gas fire pit burner?
- What size burner ring do I need for my fire pit's diameter?
- How big should a fire pit be for my patio and seating area?
- How many BTUs does a fire pit need for you to actually feel heat outdoors?
- How deep and wide should the burner pan be relative to the fire pit enclosure?