A brief History of Radiators

In the 19th Century interest in hygiene, personal comfort and the decline in disease, were met with the development of central heating, water, piped gas and a network of underground cast iron sewers.

These systems all improved with the coming of the industrial revolution.

Mass production of cast iron radiators made central heating affordable to many. Some radiators were elaborate and included special warming chambers for plates and linen. Ornamental grilles provided decorative cover for functional heaters in public places.

By the turn of the 20th Century it was common to have all these modern amenities as an integral part of the building.


Cast-iron radiator enclosure with marble top at Lanhydrock House, Cornwall (Photo: Frank Ferris, CIBSE Heritage Group)

The term ‘radiator’ is a misnomer since for column radiators some 70 per cent of the heat output is by convection (from the circulation of warm air), not radiation. The development and mass production of radiators was an American phenomenon, the first patents dating from around 1841. Early radiators were variously shaped ‘heat distributors’, a mixture of pipes and metal plates. Then came the introduction of vertical wrought-iron welded tubes fixed between horizontal top and bottom headers. These were followed by the ‘looped tube’ type, an inverted-U, fixed to a base plate, used for both steam and hot water. Tasker in Philadelphia patented a primitive sectional radiator in 1858. It is the factory mass production of radiator sections that could be connected together that distinguishes them from pipe coils.

Radiators, coils and coil-cases from the 1900 catalogue of Mackenzie & Moncur, Edinburgh

Radiators, coils and coil-cases from the 1900
catalogue of Mackenzie & Moncur, Edinburgh

Another pioneer was Joseph Nason who had spent time working in England with AM Perkins. It was Perkins who devised a high-pressure system of hot-water heating in 1831 which used a solid-fuel-fired brick furnace or metal chamber containing a sinuous coil of small-bore seam-welded wrought iron pipe. With a 6mm thick wall, the pipes were capable of operating at temperatures approaching 170°C and pressures close to 15 times atmospheric pressure. The system gained rapid acceptance and was installed in many important buildings but the concerns of insurance companies led to the system being operated at lower temperatures and pressures and it was later largely discontinued. However, modified systems, converted to oil-firing can still be found in a number of churches and chapels (below). The small bore pipe was distributed around the space to be heated, sometimes rising in banks of concertinaed coils like a modern radiator.

Until 1892 numerous American manufacturers produced a variety of designs, many highly ornamental, but in that year the three principal manufacturers merged to form the American Radiator Company. This firm, trading in Britain as the National Radiator Company, opened a factory in Hull in the early 1900s where they manufactured Ideal radiators. During the 1890s, radiators of American manufacture were imported into Britain, but from the turn of the century the domestic radiator manufacturing industry became predominant. Radiators were often housed in decorative casings (above, top picture).

Early British patents for hot-water radiators include those of Keith (1882 and 1884), Waters (1882), Cannon (1887) and Heap (1887). At the end of the 19th century, one expert claimed that British radiator design had fallen behind the current American offerings. However, this opinion was based on external appearance and not on the technical performance. British designs were generally plain, although there were exceptions. American ones were ornate. Gradually, improvements in foundry technology enabled more elaborate castings to be made. Radiators having one, two and then three columns became available. By 1917, radiators with four columns were being used.

Although probably developed some 50 years earlier, it was not until the beginning of the 20th century that the ventilating radiator was gaining acceptance. The idea was to remedy the lack of ventilation afforded by the ordinary ‘direct’ radiator. Essentially, the lower part of the radiator was blanked off against the entry of room air, and fresh air was fed into the base of the radiator by a channel in the wall behind it. These were sometimes termed ‘indirect’ radiators when located outside the room being warmed.

In 1904, claims and counterclaims relating to the introduction of radiators into Britain abounded. Acknowledging that steam radiators were of American origin, the firm of Longden in Sheffield claimed to have played a major part in introducing hot-water radiators to the British market. Rosser & Russell of London claimed to be the original inventors of the ventilating radiator, but did not give a date. Other claimants include The Thames Bank Iron Company and Weekes & Company. The case remains unproven, but one of the earliest is the ventilating radiator introduced by Walter Jones in 1881. His radiator design was awarded a silver medal in the same year.

A hot-water heater with decorative vertical tubes by Vincent Skinner found in a Bristol church (Photo: Frank Ferris, CIBSE Heritage Group)

A hot-water heater with decorative vertical tubes by Vincent Skinner found in a Bristol church (Photo: Frank Ferris, CIBSE Heritage Group)

The number and variety of radiator styles and pattern names available as the Victorian era came to a close is overwhelming. In 1891, Keith was advertising both the Universal and the Ornamental, while the Coalbrookdale Co listed its Hydro-Caloric (Heap’s Patent). By 1897, the American Radiator Co was promoting in London their National Single Column and Rococo designs. H Munzing in London was importing a variety of American radiators including Royal Union, Coronet, Union, and Walworth Patent. Longden of Sheffield featured the Sunbeam (Leed’s Patent). Wontner-Smith Gray of London had the Finsbury, while the Meadow Foundry of Mansfield made the Count and the Peer. Other British companies merely advertised their radiators as ‘ornamental’ or ‘special,’ including firms like Haden of Trowbridge, Williams of Reading, and Thames Bank Iron and WG Cannon, both in London. Other early British manufacturers include Beeston, Crane, Hartley & Sugden, Lumbys, National Radiator (later Ideal Standard), Vincent Skinner (above right) and Wm Graham.

In 1906, the London catalogue for the American Radiator Company listed: Astro Hospital Swinging, Circular, Colonial Wall, Corner, Curved, Detroit, Excelsior, Italian, National, Peerless, Perfection, Primus, Rococo, and Sanitary Pin. Many of these came in a choice of heights, widths, column numbers/ arrangements, and in ‘flue’, ‘ventilating’ and ‘non-ventilating’ designs. (See Recommended Reading for sources of further information on makes and styles of Victorian and Edwardian radiators and stoves).

The Ideal Fitter Book

Click on the picture above to read The Ideal Fitter Book

Early radiators and heating systems are of special historic significance both in their own right and as part of the character and significance of a building. If the building is listed, the permission of the local authority (listed building consent) will be required for any alterations which affect the character of the building as a listed building. This could include the removal of any part of the heating system, including the boiler itself, but it does not mean that the building must continue to be heated by an antiquated or inefficient system.

The importance of sustainability is well recognised, and the use of efficient heat generation is a key element in the sustainable adaptation of historic buildings. In some cases it may be possible to adapt an existing system to accommodate a new and more efficient heat source. In other cases it may be necessary to leave the existing appliances in situ, and run a new system alongside it, maintaining the existing ducts and appliances.

Whichever approach is taken, it is vital to seek professional advice from a qualified consultant who is used to dealing with historic fabric. Heating equipment should only be operated, opened up or dismantled by competent engineers familiar with health and safety procedures and having appropriate tools and equipment. Needless to say, rotating equipment, high-pressure pipelines, fuel systems, steam and electrical systems may be hazardous.