Radiant heating
Heat transfer mechanisms include:
All bodies which are hotter than 0°K emit thermal radiation. They also absorb thermal radiation emitted by their surroundings. The difference in the total amount of radiation emitted and absorbed by a body at any given moment may result in a net heat transfer which will produce a change in the temperature of that body.
Solar radiation may be considered to include the ultra violet, visible and near or short wave infra-red radiation. However, most 'terrestrial' radiation, emitted by bodies at normal temperatures on earth, is far or long wave infra-red radiation.
Radiant heat transmits in straight lines, only warming surfaces that are ‘visible’ to the source. However, these surfaces in turn re-radiate heat and warm air adjacent to them by convection. This allows heat from a radiant source to distribute through a space. Because it is directly heating, rather than heating the air (as in convective heating), it can be more efficient, particularly in large spaces, in spaces with poor insulation or in unenclosed or semi-enclosed spaces.
Radiant heating systems tend either to be low-temperature systems spread over large surface areas, or high temperature localised systems.
Radiant heating systems include:
- Underfloor heating systems.
- Wall heating systems (including tempering heating).
- Radiant ceiling panels.
- Integrated service modules.
- Gas fired heated tubes.
- Gas powered ceramic burners.
- Local electric heaters.
- Open fires.
Some radiant heating systems also heat by convection, for example hot water radiators, often found in domestic buildings, radiate heat directly to their surroundings, but also draw air through heated elements resulting in convective heating.
Water-based systems such as underfloor heating can be used to provide cooling as well as heating. Radiant heating systems can incorporate renewable energy sources such as solar thermal panels, solar photovoltaics, ground source heat pumps, air source heat pumps and so on. They may also be used in combination with thermal mass and night-time purging.
Compared to other forms of heating, radiant heating (depending on the system used) can be:
- More healthy, separating heating from ventilation, and so reducing problems associated with dust, pollen and other pollutants.
- More durable.
- More comfortable, giving a more even temperature distribution.
- More instantaneous.
- Space saving and unobtrusive.
- Quieter.
- Less expensive to run in certain situations. Low temperature systems in particular can run at a lower overall temperature than conventional heating systems whilst still achieving comfortable conditions.
- Easier to maintain.
- More directed.
Radiant heating also has less impact on air moisture content than other heating methods.
However, depending on the system adopted:
- High temperature electric radiant heaters can be expensive to run.
- It can impose restrictions on floor and wall coverings.
- It can be expensive to install.
- It can be less effective at cooling, and there can be condensation issues.
- There can be poor familiarity amongst designers and installers.
- It can be difficult to retrofit.
- It can be difficult to repair.
[edit] Related articles on Designing Buildings Wiki
- Air handling unit.
- Approved documents.
- Building services.
- Building services engineer.
- Building regulations.
- Co-heating test.
- Cold stress.
- Cooling.
- Corrosion in heating and cooling systems.
- Fan coil unit.
- Heating.
- Heat pump.
- Heat recovery.
- Heat stress.
- Heat transfer.
- HVAC.
- Radiation.
- Tempering heating.
- Thermal comfort.
- Underfloor heating.
- Visible light.
Featured articles and news
CIAT responds to the updated National Planning Policy Framework
With key changes in the revised NPPF outlined.
Councils and communities highlighted for delivery of common-sense housing in planning overhaul
As government follows up with mandatory housing targets.
CIOB photographic competition final images revealed
Art of Building produces stunning images for another year.
HSE prosecutes company for putting workers at risk
Roofing company fined and its director sentenced.
Strategic restructure to transform industry competence
EBSSA becomes part of a new industry competence structure.
Major overhaul of planning committees proposed by government
Planning decisions set to be fast-tracked to tackle the housing crisis.
Industry Competence Steering Group restructure
ICSG transitions to the Industry Competence Committee (ICC) under the Building Safety Regulator (BSR).
Principal Contractor Competency Certification Scheme
CIOB PCCCS competence framework for Principal Contractors.
The CIAT Principal Designer register
Issues explained via a series of FAQs.
Conservation in the age of the fourth (digital) industrial revolution.
Shaping the future of heritage
Embracing the evolution of economic thinking.
Ministers to unleash biggest building boom in half a century
50 major infrastructure projects, 5 billion for housing and 1.5 million homes.
RIBA Principal Designer Practice Note published
With key descriptions, best practice examples and FAQs, with supporting template resources.
Electrical businesses brace for project delays in 2025
BEB survey reveals over half worried about impact of delays.
Accelerating the remediation of buildings with unsafe cladding in England
The government publishes its Remediation Acceleration Plan.
Airtightness in raised access plenum floors
New testing guidance from BSRIA out now.