How to Choose the Best Patio Heater: Size, Fuel and Mounting

The best patio heater is the one whose published coverage matches the spot where people sit, on a fuel and mounting your site allows. Start with three facts: the square feet you want warm, the ceiling height and how open the sides are. Under a roof with a 240 V circuit available, a hardwired electric heater fits. In open air, a propane or natural gas heater does. This guide helps you select a heater and does not rank them. Firepit HQ has not tested any heater, and every figure comes from a maker's document listed in the sources.

Electric, Propane or Natural Gas?

• Electric: a hardwired fixture, mostly on a 240 V circuit, listed at 6.3 to 25 A at that voltage. A licensed electrician runs it. There is no flame and no tank. Inputs run from 1,500 to 6,000 W for the makers covered in the infrared patio heater guide. Bromic says to mount its electric heaters under cover where possible. Heatstrip's Intense manual says that model does not need full protection.
• Propane: the portable route. Heatstrip's portable heater runs 32,225 BTU/h and Bromic's freestanding tower 38,500, each from a 20 lb cylinder. You refill or swap cylinders. Bromic requires open-air placement, and Heatstrip says to use its heater only in a well ventilated area.
• Natural gas: the fixed route. Bromic's Tungsten Gas comes in 26,000 and 43,000 BTU/h, Heatstrip's wall-mounted heater is 32,225 BTU/h, and Lava Heat Italia towers come in natural gas versions. Bromic's manual says a gas heater must be installed by authorized persons under local code or NFPA 54. A licensed gas fitter sizes the line, and the gas line sizing calculator shows the math to expect.

A gas heater can still need power. Bromic's wall and ceiling Tungsten Gas lists a rated current of 110 V and 2 A on its cut sheet.

Freestanding, Wall or Ceiling Mounting

Freestanding needs floor space and headroom. Bromic's freestanding heater is 2,160 mm (7.1 ft) tall and weighs 123.5 lb. Its cut sheet lists a minimum floor clearance of 121 in and draws it from floor to ceiling, with 36 in above the heater and to the side. Lava Heat Italia states a minimum ceiling height for each tower. The Positano Capri is 72.5 in tall and needs 8 ft 0.5 in, and the 2G and Lava Lite at 92.5 in need 9 ft 8.5 in, which is the tower height plus the 24 in the page requires overhead and on all sides. The page adds that a standard 8-foot covered patio will not take any of them. Bromic's freestanding manual lists a flame failure device and an anti-tilt switch, and Lava Heat Italia lists tilt shut-off and flame-failure protection on its towers, so check for both on any freestanding unit.

Wall mounting frees the floor. Bromic's Tungsten, Platinum and Cobalt electric heaters sit at least 72 in above the floor, and so do Infratech's when labeled UL Listed (8 ft when labeled UL/CUL). Bromic's Tungsten Gas wants 96 in and recommends a heat deflector if the space overhead is under 42 in. Heatstrip's manual says coverage drops by up to 40 percent when its electric Classic is wall mounted at an angle.

Ceiling mounting puts the heater over the seating. Bromic publishes a 96 in ceiling minimum for its electric heaters, Heatstrip's strips need 2.1 m, and Infratech's flush-mount frames need a drywall pocket built into a flat ceiling. For gas, Heatstrip's brochure says its wall-mounted heater needs only 500 mm overhead because of its reflector, but that heater's manual says not to use it under any overhead, so get Heatstrip's answer in writing.

Quick Picks by Situation

How Big a Heater Do You Need?

No published standard says how much heat a patio needs. ASTM F2644 is a test method that rates a commercial heater's effective heated area, for gas and electric models. It rates the heater and says nothing about your patio, and I did not read its text. What you can use is each maker's published coverage.

1. Measure the zone where people sit, not the whole patio.
2. Note the mounting height you can actually reach.
3. Choose the exposure that matches your space, covered and walled or open.
4. Find the maker's published area for that height and exposure. When there is only one number, read how it is qualified: Bromic marks its gas figures "in ideal conditions," and Infratech calls its chart figures average coverage.
5. Cover a large zone with more than one heater. Bromic wants at least 20 in between its electric heaters.

The last column is calculated here. In watts, Infratech's chart works out to 40 to 64 W per sq ft, Heatstrip's Classic to 46 to 56 outdoors, and Bromic's electric cut sheets to 24 to 37.5. Heatstrip's Classic manual sets a minimum of 46 W per sq ft for a protected outdoor area; its Classic rows come from the manual's selection guide, since its spec table gives the 3,200 W a narrower 54 to 65 sq ft. Watts convert at 3.412 BTU/h each, the ratio in Infratech's own table, where 4,000 W is 13,648 BTU and 6,000 W is 20,472. Electric input and gas input are not the same thing, so read the column as each maker's own claim and nothing more. Lava Heat Italia's coverage figures are left out because its pages do not line up. The Positano page lists 400 sq ft for the 42,000 BTU Capri and 350 for the 56,000 BTU Lava Lite.

The BTU calculator lists these models and their sources and returns a range for your area.

Do Patio Heaters Work in Wind and Cold?

They work less well, and makers say so. Infratech's chart notes that well-protected spaces generally exceed its average coverage and that heaters may cover less in extremely cold or windy conditions. Its FAQ says colder or draftier areas may need more heat. It also cites Pacific Gas & Electric testing that puts a good installation at 3 to 7 degrees of perceived warmth at 60°F. Infratech says infrared heat does not simply blow away in a breeze, and its own chart still carries the caution.

Heatstrip's Classic figures show the effect in numbers. The 3,200 W model covers 86 sq ft indoor protected, 69 outdoor enclosed and 57 outdoor exposed, a drop of about a third. Schwank's tip for colder locations is to choose its 80,000 or 115,000 BTU/h models.

Gas heaters publish wind speeds. Bromic's Tungsten Gas manual says the heater is designed to work in winds up to 10 mph and can perform worse or fail in high wind or extreme saturation, though the product page says 8 mph. Heatstrip's brochure gives its wall-mounted gas heater a wind rating of 16 km/h, about 10 mph. Bromic's Platinum electric manual calls that heater wind resistant and gives no speed.

Reasoning from those numbers, I would size an open patio from the exposed figure and shelter the seating zone before adding output.

Covered or Open: Which Heaters Fit?

Electric heaters are the natural fit under a roof. Gas heaters carry location rules. Bromic's Tungsten Gas manual allows use only in an above-ground open-air situation with natural ventilation, and says it is not approved for indoor use. Among the layouts it permits are a roof over no more than two walls, and a roof over more than two walls only if at least 25 percent of the total wall area is completely open and at least 30 percent of the remaining wall area is open and unrestricted. It also says to protect the heater from rain.

Those are one maker's rules, and your manual governs. Fire codes can add limits of their own for portable propane heaters, and outdoor heaters for covered patios goes through the model code and the makers' roof rules. For the electric makers side by side, see Bromic vs Infratech vs Heatstrip.

How Long Does a 20 lb Propane Tank Last on a Patio Heater?

A 20 lb cylinder holds 4.7 gallons of propane (Manchester Tank), and a gallon holds 91,500 Btu (PERC). Multiply, then divide by the heater's BTU/h.

• Bromic's freestanding heater at 38,500 BTU/h: 430,050 Btu, or about 11.2 hours at full output.
• Heatstrip's portable heater at 32,225 BTU/h: about 13.3 hours.

To cost an hour of heat without a price printed here, divide the BTU/h by 91,500 for gallons of propane per hour, about 0.42 for the Bromic freestanding, and multiply by what you pay. For electric, multiply kilowatts by your rate per kWh. A lower setting stretches the hours. Bromic's manual describes adjustable heat output. PERC says vaporization slows when the air is colder and the tank holds less liquid, so on a cold night a 20 lb cylinder can fall behind the burner before it is empty. Heatstrip's manual says to use a 20 lb tank with an overfill prevention device and never fill it past 80 percent. The propane tank runtime calculator runs your burner.

What to Check Before You Buy

• The zone: measure the seating area and the mounting height before you read a coverage number.
• The supply: a 240 V circuit and an electrician, a licensed gas fitter for natural gas, or a 20 lb cylinder and a place to swap it.
• The headroom: ceiling height against the heater's published minimum, plus the 24 in Lava Heat Italia adds around its towers.
• Open-air limits: the manual's rules for roofs and walls, if the heater is gas.
• The coverage basis: mounting height and exposure behind each published area.
• The listing: the safety mark on the label and the manual for your exact model, with the warranty terms.
• Local rules: your building department, your installer and, for fire code questions on the patio, the state fire code library.