How Does a Patio Heater Work? | Radiant Heat Basics

The physics behind how a patio heater works comes down to one principle: radiation. Instead of warming the air around you like an indoor space heater, a patio heater sends infrared energy outward in straight lines. That energy heats your skin, your chair, and the table in front of you the moment it lands on them. The air stays cool, but you feel warm—which is exactly why these units function so well outdoors, where breezes would otherwise carry heated air away in seconds.

Radiant Heat: The Core Mechanism

Radiant heat is the dominant principle in virtually every patio heater on the market. The unit generates heat at a source—a burning flame or an electric element—and that heat travels outward until it strikes a solid object or a person. A reflector dome above the source helps direct more of that energy downward and outward instead of letting it escape uselessly into the sky.

This is the same reason you feel warmth from the sun on a cold day: the radiation itself travels through cold air without warming it, then heats whatever it touches. Wind barely matters, because moving air cannot carry away radiation the way it carries away convected heat.

Gas vs. Electric: Two Ways to Make the Heat

Gas models, fueled by propane or natural gas, work by burning fuel at a burner. The flame heats a metal screen or element above it, and that element glows and radiates heat. A reflector dome then focuses that energy toward the seating area. Propane versions carry their fuel in a tank mounted at the base, which makes them portable; natural gas units connect to a fixed line and stay put.

Electric models skip combustion entirely. Electricity powers a heating element or lamp that produces infrared radiation directly, with no flame and no fuel to manage. Many electric units are rated up to 1,500 watts, and they are generally simpler to install—though they must sit near an outlet or be hardwired, depending on the model.

Types, Placement, and What to Expect

Patio heaters come in several configurations, and the right one depends on your space. Freestanding pole models with mushroom-style domes are the classic gas choice—portable, powerful, and easy to move around a patio or deck. Wall-mounted and ceiling-mounted units preserve floor space and are common in covered porches and pergolas. Tabletop and tank-top models heat smaller areas and suit cozy seating nooks.

Once you understand how a patio heater works, one expectation matters most: these units are spot heaters, not air heaters. They warm whatever faces them, so positioning is everything. Place the heater where the radiant beam reaches your seating area directly, and you will feel the difference immediately. Expecting it to warm every corner of the patio like an indoor furnace will only lead to disappointment.

If you’re ready to shop, our tested roundup of the best electric patio heaters compares the top models for coverage, wattage, and mounting style.

How to Light a Propane Patio Heater Safely

For a typical propane model, the ignition sequence is straightforward. Open the tank valve, place the propane tank securely in the cylinder housing, then press and turn the control knob to the pilot position. Hold it there, press the igniter button until the burner lights, and keep holding the knob for a few seconds after ignition before releasing it and setting your desired heat level.

If the burner fails to ignite after several attempts, stop and consult the manufacturer’s instructions rather than forcing the unit. Combustion produces flame, so correct fueling and outdoor clearance are non-negotiable. Electric models sidestep these concerns entirely, which is one reason many homeowners prefer them for covered spaces.

Wind exposure matters for both types. Radiant heat holds up far better outdoors than convection heating, but performance still depends on placement. A unit tucked into a sheltered corner will always outperform one standing in an open, gusty area.