Patio heater FAQ

Roughly 20 BTU per square foot for an open patio in mild conditions — but the multiplier is the whole answer. An exposed site in real wind can need two to three times what an enclosed one of the same size needs. A 200 sq ft open patio lands near 4,000 BTU sheltered and well past 10,000 exposed. Put your own numbers into the BTU calculator, which prints the formula it used.

A 1,500 W electric heater costs about $0.28 an hour at the current US average of 18.34 cents per kWh. A 46,000 BTU propane heater burns roughly half a gallon an hour, about $1.35. Propane costs more per hour and produces far more heat, so the comparison that matters is cost per BTU — it is on the cost page.

Electric, per unit of heat actually delivered to a person, at typical US rates — and it is not close once you account for infrared putting its output where people are instead of into the air. Propane wins on total output and on needing no outlet. The full comparison, with the arithmetic.

About 10 hours on a typical 46,000 BTU mushroom heater at full output, and proportionally longer turned down. A 20 lb cylinder holds roughly 4.7 gallons, which is about 430,000 BTU. Runtime for every cylinder size and burn rate.

Nine times out of ten it is wind, and this is the most misunderstood thing in the category. A breeze does not reduce a heater's output — it removes the warmed air that output produced, before you feel it. That is why a heater correctly rated for your patio size can still leave you cold. What to do about it.

Yes, and it is usually the cheapest thing you can change. Blocking the wind on the exposed side of a patio can cut the heat you need by more than half — a bigger effect than buying a bigger heater. Windbreak options, including ones you can build.

Only with the clearances the manufacturer specifies, and many units publish a minimum overhead clearance that a standard patio roof does not give you. Gas heaters also produce combustion byproducts that need ventilation. Your own manual is the authority, always. Covered patios, in detail.

With the right base clearance and a stable, level footing, yes — but tip-over risk matters more on a deck than anywhere else, and downward radiant heat is a real consideration for some designs. Wood decks, and the general clearance rules.

They answer different questions. Infrared warms objects and people directly, which makes it far more effective in wind and much cheaper to run. Propane warms the air, produces far more total heat, and needs no outlet. Side by side.

Mushroom heaters spread heat in a wider circle and generally cost less. Pyramid heaters look better and concentrate heat closer in. Neither is meaningfully warmer than the other at the same BTU rating. The comparison.

For atmosphere, easily. For warmth, a fire pit heats one side of you at a time and needs you close to it, while a heater covers a circle. They solve different problems, and plenty of patios want both. Heater vs fire pit.

Less than you would expect. Enclosure is the single biggest variable in the sizing calculation, often halving the requirement compared with the same area open to the sky — at which point ventilation becomes the constraint instead. Screened porches.

Usually the thermocouple, the tip-over switch, or a tank that is emptier or colder than you think. There is an order to check them in that saves taking the thing apart. The fault tree.

Less than it implies, and there is no standard behind the claim. A published radius describes where some warmth is detectable in still air, not where a patio is comfortable. We convert every claim into an area and label whose number it is. Coverage, honestly.

They measure the same thing in different units: 1 kW is 3,412 BTU per hour. Electric heaters are sold in watts and gas heaters in BTU, which makes them look incomparable when they are not. The conversion, and why it misleads.

Neither. This site earns Amazon Associates commissions when a reader buys through a link, at no extra cost to them. No free product, no sponsored placements, no paid positions on any list. The full disclosure.

No, and we say so on every page. There is no test lab and no owned units. What this site does instead is compile published manufacturer specifications and print the arithmetic they imply, so you can check every figure yourself. How we pick.

Because a score implies an evaluation we did not perform. You get a plain verdict, a stated best-for, an explicit not-for, and the computed numbers behind all three. We also emit no rating markup to search engines, deliberately.

Not exactly. We use national US averages, both sourced and dated, and residential electricity rates vary by more than a factor of three across the country. Every cost page shows the formula so you can substitute the rate from your own bill. Cost to run.

Disconnect the cylinder and store it outdoors and upright — never in a garage or basement — and protect the burner assembly from moisture more carefully than the paintwork. Off-season storage.

Tell us which page and which figure at our contact page. Every number here has either a named source or its arithmetic printed beside it, so a correction can be about a specific step — and we fix it on the page rather than quietly.