Portable Gas Heaters

A common starting estimate is 30-60 BTU per square foot for typical conditions, adjusted upward for poor insulation, high ceilings, drafty or outdoor spaces, and colder climates. This is a rough guideline, not a precise calculation — for critical applications like concrete curing, use a proper heat-loss calculation rather than square footage alone.

Unvented heaters release combustion byproducts, including carbon monoxide, directly into the space, so they're only safe indoors with confirmed adequate fresh-air ventilation per NFPA 58 and local code, and generally require a functioning carbon monoxide detector in the space. Enclosed or poorly ventilated indoor spaces should use a vented heater or confirm the unvented unit is explicitly rated and sized correctly for that enclosed volume.

A forced-air heater uses a blower to push heated air through the space, which efficiently heats large open volumes but loses effectiveness in drafty or open-air conditions. A radiant heater emits infrared heat that directly warms objects and people in its line of sight, working well outdoors or in drafty spaces where forced air would just blow away.

No, not without a manufacturer-approved conversion kit — natural gas and propane burn at different pressures and require different orifice sizing, so using the wrong fuel without proper conversion is a safety hazard and typically voids the heater's certification. Confirm the heater's fuel type matches your supply before purchasing.

Look for a tip-over safety switch that automatically shuts off the heater if it's knocked over, and for unvented indoor-rated units, an oxygen depletion sensor (ODS) that shuts the heater off if oxygen levels in the space drop too low. These are standard on heaters certified for the space they're rated for, but confirm both features are present before using a heater in an enclosed area.