Infrared Patio Heaters: Hardwired or Plug-In, Voltage and Mounting

An infrared patio heater warms the people and surfaces under it instead of the air. The electric models from Bromic, Infratech and Heatstrip are hardwired fixtures that run mostly on 240 V, draw 6.3 to 25 A at that voltage, and mount about 6 to 12 feet up. The one plug version in their documents, a 2,400 W Heatstrip Enhance, still calls for fixed wiring by a licensed electrician. Settle the voltage, the amps and the mounting height before you pick a model.

Every figure below is cited in the sources. I have not tested any of these heaters. For the three makers side by side, see Bromic vs Infratech vs Heatstrip.

What Makes a Heater Infrared?

Infrared heat travels as radiation and warms whatever absorbs it: skin, a tabletop, the floor. Infratech says its quartz elements heat solid objects rather than the air, so the heat does not simply blow away in a breeze. The catch is the footprint. Heatstrip's manuals show the warmest spot directly under the heater and the temperature falling as you move away, so people have to sit inside that pattern.

Infrared is split into bands by wavelength. Ceramicx, an infrared element maker, gives short-wave as 0.78 to 1.4 micrometers, medium-wave as 1.4 to 3.0 and long-wave as 3 to 1,000. Its white paper on comfort heating says the longer bands are better absorbed by human skin.

On a patio, the difference you notice is light. Infratech says short-wave halogen heaters throw very bright, harsh-colored light, and that its medium-wave quartz elements give a soft glow that is practically unnoticeable. Bromic calls its Tungsten and Cobalt elements a soft glow with no harsh glare.

Only Infratech names its band in the documents I read. If glare matters on your patio, ask the maker which band the element is.

Are Electric Patio Heaters Hardwired or Plug-In?

Hardwired, nearly always. Bromic's Tungsten Electric manual says the heater must be permanently installed and hard wired by an authorized person, and Infratech's manuals say the same with a licensed electrician. Heatstrip's manuals call for a fixed installation by a licensed electrical professional, and its Max DC Commercial must be hard-wired.

The one exception is Heatstrip's Enhance manual, which describes a 2,400 W plug version and a 3,200 W hardwired version, then says the fixed wiring must be installed by a licensed electrician in both cases. Ask Heatstrip which applies to the US model you are buying.

The other variation is voltage. Infratech's FAQ says a 120 V heater tops out at 1,500 W and suits garages, indoor work areas or an outdoor space no larger than 5 by 5 feet, though its reference manual lists a 1,600 W SL-1612 at 120 V and 13.3 A. For anything larger it points to a 240 V circuit, which it says takes the same amount of wiring and two spaces in the breaker panel.

The wiring is code work. Heatstrip's manual says US installs follow the National Electrical Code (NEC). Bromic's says the installer must meet the local electrical code, use supply wire rated at least 90°C, and build a disconnect into the fixed wiring. Article 424 of the NEC covers fixed electric space-heating equipment. EC&M's summary of 424.3(B) says it counts as a continuous load, which puts the branch circuit at 125 percent of the heater's current, and Infratech specs its relay panels the same way, fed at 125 percent of the heaters' full amperage. Your inspector decides which NEC edition applies, and a licensed electrician sizes the circuit.

What Voltage Does an Electric Patio Heater Need?

Most of the lines here are 240 V single phase. Infratech also lists 208, 277 and 480 V models, and Bromic's Tungsten comes in 208, 220 to 240 and 277 V. Heatstrip's US models are listed at 240 V.

Check your actual voltage before you order. Infratech says many new homes and businesses are supplied with 208 V, and that a 240 V heater on 208 V power produces only about 60 percent of the desired infrared energy. Models built for 208 V draw more current for the same watts. Bromic's 6,000 W Tungsten lists 21.66 A at 277 V, 25 A at 240 V and 28.85 A at 208 V.

Patio Heater Amps and Circuit Sizing

The makers print the current. The last column is 125 percent of it, which is where an electrician starts.

Sources: Infratech C-Series and CD-Series page; Bromic cut sheets and Tungsten manual; Heatstrip Classic manual.

The last row shows why the big heaters are a panel question. At 125 percent, one 6,000 W heater does not fit a 30 A breaker. Heatstrip's manual sets its own rule, an overcurrent device rated at 150 percent of the heater's rating, which works out to about 20 A for the 13.3 A Classic. Bromic says to use only one branch circuit for its 2,000 and 3,000 W models. Follow the manual for your model and your electrician's calculation.

How Many Watts Does a Patio Heater Need Per Square Foot?

Makers publish the area each heater covers, which is the closest thing to a sizing rule. Divide watts by that area and they do not agree.

Three things explain the spread. Infratech ties each area to a mounting height. Heatstrip's selection guide gives a figure for each exposure, falling about a fifth from indoor protected to outdoor enclosed and a third to outdoor exposed, though the same manual's spec table gives the 2,400 W only 43 to 54 sq ft. Bromic's own documents disagree: its cut sheets give up to 130 and 160 square feet for the 4,000 and 6,000 W Tungsten and Cobalt, and its manuals give up to 120 and 144.

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. Heatstrip says coverage drops by up to 40 percent when its Classic is wall mounted at an angle. Reasoning from those numbers, I would size from the cautious rows. A patio open on two sides sits closer to Heatstrip's exposed row than its enclosed one. The BTU calculator shows the full range for your area.

Heatstrip also advises spot heating the high-use zone, such as the dining table, instead of the whole patio. Infratech cites Pacific Gas & Electric testing that puts a good installation at 3 to 7 degrees of perceived warmth at 60°F, and says more than 7 is too warm to sit in for long.

Mounting Height and Clearances

Each maker publishes a minimum mounting height.

Clearances come from each manual and are not interchangeable.

• Infratech: keep combustibles at least 6 in behind the heater, 18 in from the sides and ends, and 36 in in front. Wall and ceiling mounts sit at least 6 ft above the floor if the label says UL Listed and 8 ft if it says UL/CUL Listed.
• Bromic: leave 3 ft in front, and at least 20 in between heaters. The Tungsten manual says its stated clearances reflect a surface 117°F above room temperature and that the installer must protect nearby materials.
• Heatstrip: keep 100 mm (3 15/16 in) from the ceiling or wall behind the heater and 2.1 m above the surface below. Lights, fans and sprinklers must not sit below it, and it must not go directly below or in front of a socket outlet.

Orientation matters too. Bromic says the elements must be horizontal and that mounting vertically voids the warranty. Infratech's flush-mount frames go only on a flat, level ceiling. Heatstrip says the heating surface must never face the ceiling.

Can an Infrared Patio Heater Get Rained On?

The makers publish ingress protection (IP) ratings. IPX4 means protection against splashing water from any direction, and IPX5 means protection against water jets, per the IEC 60529 summary in the sources. A 5 in the first digit, as in Heatstrip's IP55 rating for the Classic, adds dust protection.

An IP rating is not the same as a damp or wet location listing. OSHA's definitions put a roofed open porch in the damp category and an unprotected, weather-exposed spot in the wet category. The manuals I read for these heaters do not use the terms "damp location" or "wet location", so ask your inspector which listing your location calls for.

The makers' advice differs. Bromic's Tungsten and Cobalt manuals say to mount outdoors with the face angled down, under cover where possible, and Platinum's says the unit must not be directly exposed to rain. Heatstrip's Intense manual calls that model suitable for permanently exposed courtyards and patios. The rating also depends on the wiring parts: Bromic says to use IPX4 rated conduit fittings to keep a Tungsten at IPX4.

Controls: Switches, Dimmers and Timers

• Infratech: on/off and duplex switches (20 A maximum per switch), an INF regulator that cycles single-element heaters up to 3,000 W (15 A) and is not a dimmer, solid-state zone controllers with digital timers from 15 minutes to 4 hours, and a Universal Control that works with a 0 to 120 V dimmer. Infratech says its controls adjust a heater from zero to 100 percent of power, and that competitor controls may void its warranty.
• Bromic: Affinity on/off and dimmer controllers, with the dimmer adjusting heat in 1 percent steps. A single channel handles 6 kW, and the app adds Wi-Fi and Bluetooth control, timers and schedules. Eclipse has its own controller and three heat settings.
• Heatstrip: the Classic comes with or without remote and app control, and Intense and Enhance include them. The brochure gives every remote and app model three heat levels and a timer from 0 to 24 hours.

Heaters draw their rated watts at full power: 1.5 kWh an hour at 1,500 W, 6 kWh at 6,000 W. Multiply by your utility rate. Infratech's installation manual says not to leave powered heaters unattended, and the Bromic and Heatstrip manuals call for extreme caution whenever a heater is left operating unattended.

What to Check Before You Buy

• Voltage at your panel: 208 or 240 V, confirmed by an electrician.
• Amps and breaker space: use the listed current and the manual's overcurrent rule for your model.
• Ceiling height: compare it to the mounting range for the wattage you want.
• Clearances: combustibles, fans, lights, sprinklers and outlets near the heater's spot.
• Rating and listing: IP rating, ETL or UL mark, and the damp or wet location your inspector requires.
• Coverage figure: read the basis, whether height or exposure, before you trust the area.
• Permits and codes: ask your building department about an electrical permit. For the fire code side of the patio, see the state fire code library.

If part of the space is covered, outdoor heaters for covered patios covers what suits it. For the fuel and mounting choice across electric, propane and natural gas, read how to choose a patio heater. The makers are profiled at Bromic, Infratech and Heatstrip.