How Infrared Heating Works?

Infrared heating is an electric heating system that warms people, furniture, floors and walls directly instead of mainly warming the air first. It can be installed under floors, above ceilings or in wall-mounted panels and can be used for one room or as a complete whole-home heating system.

Think of sunshine on a cold day

Have you ever stood outside on a cold day and felt warmer as soon as the sun came out, even though the air was still cool? That feeling comes largely from radiant energy reaching your skin directly.

Infrared heating works in a similar way. It sends gentle radiant heat towards people and surrounding surfaces. Floors, walls and furniture absorb the energy, warm up and then release heat into the room.

This guide explains the process in simple terms, compares infrared with convection heating, looks at ceiling and underfloor heating film, and shows why insulation, glazing, ventilation and heat-loss calculations still matter.

What is infrared heating?

Infrared heating is radiant heating. A heating element becomes warm and emits infrared energy towards the room. When that energy reaches a person or a solid surface, part of it is absorbed and converted into heat.

This is different from a heating system that transfers most of its output to the surrounding air first. Conventional wall-mounted radiators, despite their name, commonly deliver a large share of their heat by convection: air beside the emitter warms, rises and circulates through the room. Radiant systems are designed to provide a higher radiant contribution.

Infrared heating is available in several forms, including wall panels, ceiling panels, underfloor systems and thin electric infrared heating film. The most suitable format depends on the building, surface finish, room use and required heating output.

How infrared heating works in six steps

No heating system creates free energy. The building still loses heat through walls, glazing, roofs, floors, doors and ventilation. A successful infrared system must supply enough heat to replace those losses under the intended design conditions.

Radiant heat versus convection heating

All practical room-heating systems use a mixture of heat-transfer mechanisms. The difference is the balance between them.

Neither mechanism automatically guarantees lower bills. Actual energy consumption depends on the building’s heat loss, the required temperature, operating hours, control strategy, electricity tariff and occupant behaviour.

Does infrared heating heat the air?

Yes, but not only or necessarily primarily at the heating element.

Infrared energy passes through the air and is absorbed mainly by people and solid surfaces. As those surfaces become warmer, they transfer some heat to the air touching them. The room air therefore warms indirectly as part of the overall heat-transfer process.

This distinction matters because claims that infrared “does not heat air” are oversimplified. A comfortable occupied room normally contains warm surfaces, warm-enough air and an appropriate average radiant temperature.

What is far infrared heating?

Infrared is part of the electromagnetic spectrum. We cannot see it with our eyes, but we can feel it as heat.

iHelios heating film works as a low-temperature radiant heating surface and emits predominantly long-wave, or far-infrared, thermal radiation. This is the type of gentle radiant warmth commonly associated with warm floors, walls and other heated building surfaces.

The system does not produce one single wavelength. Like every warm surface, it emits a range of infrared wavelengths. The exact distribution depends mainly on the operating surface temperature.

Far infrared is different from ultraviolet radiation and is not ionising radiation. It is simply thermal radiation emitted by a warm surface.

Infrared heating film versus infrared panels

Both technologies use electrically heated surfaces, but their form and installation differ.

iHelios heating film is designed for compatible underfloor and ceiling applications. Always check the product specification, installation method, electrical design and finish compatibility before purchase.

Ceiling heating or underfloor heating?

Ceiling infrared heating

Ceiling heating can provide a clear radiant path into the occupied space without taking up wall or floor area. A correctly designed ceiling system may work well where floors must remain untouched, where broad room coverage is required or where furniture layouts make some floor areas unsuitable.

The ceiling construction, plasterboard arrangement, insulation position, available heated area and maximum permitted output must all be considered. Read the iHelios installation guide before designing a build-up.

Underfloor infrared heating

Underfloor film creates a large, low-profile heated surface beneath compatible floating floor finishes. The finish, underlay, furniture coverage, insulation below the system and floor-temperature limits all affect performance.

Thick insulating finishes can restrict heat transfer. Fixed furniture or items that prevent heat from dissipating may also affect layout decisions. The heating area should therefore be planned around the final room design rather than estimated from total floor area alone.

Can infrared heating heat an entire house?

Yes, infrared heating can be designed as the primary heating system for an entire property, but only when the available output in every room is sufficient to meet that room’s calculated heat loss.

A whole-house design should account for:

• external walls, roofs, floors, windows and doors;
• insulation standards and thermal bridges;
• ventilation and infiltration;
• room dimensions and ceiling height;
• required internal temperatures;
• local external design conditions;
• available ceiling or floor heating area;
• electrical capacity and circuit design;
• floor or ceiling build-up constraints;
• room-by-room thermostat control.

Learn more in our guide to using infrared heating film as a main heating system.

What affects infrared heating performance?

Infrared heating performance is not determined by the heater alone. The complete building and control strategy matter.

Insulation and airtightness

Better-insulated building elements lose heat more slowly. Improving insulation and controlling unintended air leakage can reduce the output and operating time required from any heating system.

Windows and external doors

Large glazed areas, older frames and frequently opened doors can significantly increase heat loss. They should be measured and included in the room calculation.

Ventilation

Healthy buildings require ventilation, but incoming colder air must be warmed. Extract fans, trickle vents, mechanical ventilation and natural infiltration all influence heating demand.

Available heated area

A room may have sufficient total floor or ceiling area but less usable installation area after allowing for fittings, partitions, fixed furniture and manufacturer clearances.

Surface finishes

Floor coverings, underlays, plasterboard layers and decorative finishes affect heat transfer. Use only constructions approved for the relevant heating product.

Control settings and occupancy

Heating an unused room to the same schedule as an occupied room wastes energy. Independent zones, sensible set temperatures and realistic schedules are important regardless of the heating technology.

Why a heat-loss calculation matters

A heat-loss calculation estimates how much heat a room loses under specified indoor and outdoor conditions. The installed heating output should be sufficient to replace that loss and raise the room to the intended design temperature.

The basic fabric heat-loss relationship is:

This calculation is repeated for walls, windows, external doors, floors and roofs or ceilings. Ventilation and infiltration losses are then added. Real design may also require allowances for thermal bridges, intermittent operation and other project-specific factors.

A simple watts-per-square-metre rule can be useful for an early estimate, but it should not replace a proper room-by-room calculation for a primary system. Use the iHelios infrared heating calculator for an initial estimate, then request a technical review for the final design.

How thermostats and zoning control infrared heating

The thermostat does not make a heater intrinsically more efficient at converting electricity into heat. Its role is to avoid unnecessary operation and maintain the required conditions more accurately.

A well-controlled infrared system may include:

• independent room or zone thermostats;
• weekly schedules;
• floor sensors where required;
• maximum-temperature limits;
• open-window detection;
• occupancy-based automation;
• remote app control;
• lockable settings for landlords or managed properties;
• timing aligned with solar generation or off-peak tariffs.

Controls should be selected for the connected electrical load and installed in line with the wiring design. Larger zones may require contactors or other switching arrangements specified by the electrical designer.

Is infrared heating efficient, and what does it cost to run?

At the point of use, resistance-based electric heaters convert the electrical energy they consume into heat within the building. However, that fact alone does not determine the bill.

Running cost is governed by:

• installed electrical output in kilowatts;
• the proportion of time the system is energised;
• electricity price per kilowatt-hour;
• room set temperatures;
• building heat loss;
• weather;
• zoning and schedules;
• solar PV, battery use or time-of-use tariffs.

Example using a 45% duty cycle

A thermostat-controlled system does not normally remain on continuously after the room reaches its target temperature. The percentage of time it is powered is called the duty cycle.

A 45% duty cycle is an example, not a guaranteed result. The actual figure changes with outdoor temperature, insulation, glazing, ventilation, set temperature, thermostat position, occupancy and how often doors or windows are opened.

During initial warm-up or very cold weather, the system may run close to 100% for a period. In a well-insulated room after the target temperature has been reached, the duty cycle may be much lower.

Advantages and limitations of infrared heating

Common infrared heating myths

Where infrared heating can be used

Correctly specified systems can be considered for:

• houses, flats and apartments;
• new-build and retrofit projects;
• extensions and loft conversions;
• garden rooms and annexes;
• HMOs and rental properties;
• holiday accommodation;
• offices, studios and retail spaces;
• modular and prefabricated buildings;
• social-housing and commercial projects.

Suitability must be assessed for each property. Electrical capacity, heat loss, build-up design, floor finish, fire strategy and relevant Building Regulations or project standards should all be checked.

Frequently asked questions