Mario Carpo

Publication History:

“Central Heating,” in Extinct. A Compendium of Obsolete Objects, edited by Barbara Penner, Adrian Forty, et al., 61-65. London: Reaktion Books, 2021

The text posted here is a preprint draft and it is different from the published version. Please only cite from copy in print

After the loss of Roman engineering, domestic heating in medieval Europe was for centuries a sorry ad-hoc operation: rooms in some buildings had fireplaces, where people lit fires when they could.  Then came stoves, which, alongside the radiant heat they delivered, could also be used to generate hot air, hot water, or steam; as Ben Franklin and a few others soon found out, these fluids could carry heat some distance, thus separating the production of heat from its localized consumption.  The logical next step was a bigger stove, or furnace, tucked away in a service room, often in a basement; thence, heat and hot water would be delivered to a whole house or multi-storey building—a system often called central heating.  As the technical logic of the industrial revolution gained ground, it appeared that even bigger economies of scale could be reaped by centralizing and mass-producing domestic heat for entire town blocks, or even cities—so long as the costs of distribution and the related thermal losses would be less than the savings generated by more efficient and cleaner, industrial grade heat producing plants (district heating, chauffage urbain, Fernwärme, etc.): the New York City Steam Company started operations in 1882 and its successor, Consolidated Edison, to this day delivers steam for heating (and increasingly other purposes) to most of Manhattan.

When heat is produced remotely, and delivered to residents by dint of some heavy infrastructure, domestic comfort is at the mercy of various technologies for local temperature control.  Electric space heaters, and gas burners, can be switched on and off at will.  Hot water radiators, and steam radiators, typically have valves that can be open and shut, or do so automatically.  Vents can be opened and closed at will too.  But for other modes of heating local control may be more impervious, and for some centralized systems a personal, discretionary control of room temperatures has often been seen as almost impossible.  This did not happen for any overarching technical reason.  In many parts of the world non-customizable, standardized heating was for a long time a social, political, and ideological choice.

As with so many other myths of twentieth century modernism, the idea of a standardized, uniform, and universal thermal environment emerged in the course of the technophilic 1920s, and found one of its purest formulations in Le Corbusier’s early writing.[1] Corb’s plan of keeping all humans in perfectly sealed, purified environments at a steady temperature of 18 Celsius degrees—everywhere and at all times—may appear today like the hallucination of a madman, yet it was for at least two generation of modernists a realistic and operative design inspiration, instantiated and materialized in many instances, experiences, and cultural technologies of modern life, from the geodesic dome to pressurized air travel.  In the mid-twentieth century underfloor heating, a relatively new mode of central heating, appeared best suited to fulfil and express this quintessentially modernist dream.  When properly engineered, underfloor heating delivers gentle, isotropic, homogeneous heat at constant temperatures; it is as ubiquitous as it is invisible: due to thermal inertia (the delay whereby different temperatures between the surfaces result in actual heat transfer) it is slow to react to changes in the supply or demand of heat, and therefore it best works in an “always on” mode.  Underfloor heating is ideally a cradle-to-grave provision, offered to all citizens, equally, by the invisible hand of some benevolent higher authority, under the exclusive control and jurisdiction of a remote, impersonal and often unreachable central administration. 

Unlike ancient hypocausts, where heating came from flues built in the floor understructure—a technique largely maintained in many Eastern countries until industrialization—modern underfloor heating uses small hot water pipes variously embedded in the floor.  A UK patent from 1907 describing a similar system, called “panel warming”, appears to have been exploited mostly in Switzerland, and there is anecdotal evidence of some underfloor heating in use in Europe and in the US before the Second World War. In London Oscar Faber, the noted structural engineer, retrofitted panel heating to some rooms of the Bank of England before the war, and in the rebuilding of the House of Commons immediately after.[2]  Nobody knows why Chamberlin, Powell and Bon, who designed the Barbican Estate in London from 1955 onwards, chose underfloor technologies for heating all 2,014 flats of the estate, and by electric cables rather than hot water pipes embedded in all floors—a choice unprecedented at that scale, and that must have seemed at the time daring, outlandish, and quirky.  It was approved without discussion, and diligently carried out from 1963, when building started, to 1976, when the last of the three residential high rises of the Estate was completed.  The Barbican heating system was designed between 1956 and 1959:[3] 1956 is also the date of the first Clean Air Act, of the Suez Canal energy crisis, and of the inauguration of the first nuclear power station in the UK—all of which may explain the choice of electricity, instead of fossil-fired heating.  In 1959 the architects went the extra-mile to explain that ubiquitous underfloor heating in the Estate was only intended to provide a uniform “background”, on top of which residents were free to add individual heating from their own electrical fires, or space heaters, “to their personal liking”, but at their own expense.[4]

To this day, the 4,000 or so residents of the Barbican are also free to open (some) windows when the temperature in their flats goes up beyond their taste.  That’s about all the freedom they get.  The humble bimetallic thermostat has been known since the 1830s, and as an electric switch since 1886.  Thermostats are perfectly compatible with most central heating technologies, yet they are never mentioned in the Barbican technical documentation.  It is a commonplace of media studies that the TV remote control spelled the rise of post-modernism.  By introducing choice, differentiation, variation, and granular customization to the control of the immediate environment of the human body, the room thermostat is the rival and nemesis of modernist centralised heating.  The first thermostatic systems were developed in France at the end of the 18th century to provide steady temperatures for poultry breeding,[5] but modern electro-mechanical thermostats (and today’s electronic, networked thermostats) allow for and encourage controlled variations in the distribution of heat, and today’s post-modern dwellers expect that temperatures—just like everything else in the digital economy—should be served on demand: where needed, when needed, as needed.  Central heating, and with it the political and ideological project of a standardized, machine-made thermal environment, where all receive the same amount of centrally planned heat at all times, has been consigned to the dustbin of technical and social history.

 1. Le Corbusier, Précisions sur un état présent de l’architecture et de l’urbanisme (Paris: G. Crès, [1930]), 64-66.  See Reyner Banham, The Architecture of the Well-tempered Environment (Chicago: University of Chicago Press, 1984), 159-60. First published London: The Architectural Press, 1969.

2. Robert Bean, Bjarne W. Olesen, Kwang Woo Kim, “History of Radiant Heating and Cooling Systems, Part II,” Journal of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers, 54, 2 (February 2010), 51-55.

 3. Chamberlin, Powell, and Bon, Report to the Court of Common Council of the Corporation and City of London on Residential Developments Within the Barbican Area, May 1956, Appendix VI, page ix; and, (same title), April 1959, Section 3, pages 5, 8-9.

 4. Ivi, 9.

 5. Emmanuelle Gallo,”Jean Simon Bonnemain (1743-1830) and the Origins of Hot Water Central Heating,” paper presented at the Second International Congress on Construction History, Queens’ College, Cambridge, 29 March-2 April 2006.