{{Short description|Method of heating sports stadiums}} {{Infobox machine|name=Under-soil Heating Technology|manufacturer=Various|invented=1950s<ref>{{Cite web|url=https://www.football-stadiums.co.uk/articles/undersoil-heating-in-football/|date=4 January 2026|author=|title=The History of Undersoil Heating in Football Stadiums - Football-Stadiums.co.uk |publisher=MattBar ltd}}</ref>|type=Soil heating system|application=Sports stadia, Agriculture<ref>{{Cite web|last1=Williams |first1=Patricia |url=https://stadiums.world/stadiums-with-under-soil-heating-technology/|title=Stadiums with Under-Soil Heating Technology|date=27 September 2023|work=Stadiums World }}</ref><ref>{{Cite web|url=https://www.theguardian.com/environment/2023/jul/04/improving-farming-soil-carbon-store-global-heating-target|title=Improving farming soil could help store carbon and meet global heating targets|date=July 4, 2023|author=|work=The Guardian}}</ref>|fuel_source=Electric, Gas<ref>{{Cite web|url=https://www.eia.gov/todayinenergy/detail.php?id=30672|title=Today in Energy|date=|author=U.S. Energy Information Administration|publisher=EIA}}</ref>|power=Variable, depending on system size and requirements|components=Corrosion-resistant metal pipes, Energy-efficient heating elements, Automated control units}}
'''Under-soil heating''' is a method used in various sports stadia to warm the playing surface and prevent the buildup of snow or ice, helping avoid the postponement of matches due to poor weather.<ref>{{Cite web |title=The History Of Undersoil Heating in Football Stadiums {{!}} Football-Stadiums.co.uk |url=https://www.football-stadiums.co.uk/articles/undersoil-heating-in-football/ |access-date=2023-09-27 |website=www.football-stadiums.co.uk|date=18 August 2016 }}</ref> The first ground in England to have under-soil heating installed was Goodison Park in 1958.<ref>{{cite web | title=Everton firsts |publisher=Everton F.C.| url=http://www.evertonfc.com/history/everton-firsts.html| access-date=31 December 2009}}</ref>
== Technology == Under-soil heating technology is designed to address the challenges of adverse weather conditions,<ref>{{Cite web |date=2013-07-09 |title=All You Need to Know About Geothermal Heating Systems |url=https://www.bobvila.com/articles/529-geothermal-heating-systems/ |access-date=2023-09-27 |website=Bob Vila |language=en}}</ref> specifically the accumulation of ice and snow on ground surfaces. The system consists of a network of corrosion-resistant metal pipes laid beneath the soil or turf. These pipes are connected to a central heating unit that contains energy-efficient heating elements.<ref>{{Cite web |last=Massey |first=Jake |date=2023-06-30 |title=Ground source heat pumps explained |url=https://www.which.co.uk/reviews/ground-and-air-source-heat-pumps/article/ground-source-heat-pumps-explained/how-ground-source-heat-pumps-work-aMDCm2N7jZ6X |access-date=2023-09-27 |website=Which? |language=en}}</ref> When the system is activated, the heating unit circulates warm water or air through the pipes, effectively raising the soil temperature. Modern versions of this technology often include automated control units that allow for real-time monitoring and precise temperature adjustments, ensuring that the soil temperature is maintained at a level that prevents the formation of ice and snow.
There have been numerous occasions where under-soil heating's effectiveness has been questioned. On 27 December 2005, three stadia in the FA Premier League, supposedly equipped with under-soil heating, failed to stop their pitches being covered in thick snow - this led to the matches being postponed. Subsequently, on 1 January 2006, the Premier League investigated as to why the pitches at Reebok Stadium (Bolton Wanderers), Ewood Park (Blackburn Rovers) and St. James' Park (Newcastle United) were not able to repel the snow. In the U.S., a notable example of the failure of an under-soil heating system occurred in 1967, when a newly installed system at Lambeau Field in Green Bay, Wisconsin failed before the NFL Championship game. The game would go on to be remembered as the "Ice Bowl".
== Usage ==
{{Asof|2025|07|24|alt=For the 2025-26 season}}, the English Premier League requires its teams to have an undersoil heating system for their pitch.<ref>{{cite web |title=Premier League Handbook 2025/26 |url=https://resources.premierleague.pulselive.com/premierleague/document/2025/10/22/c03ebde8-8b59-4822-9f3b-bd42ed587f92/PL_Handbook_25-26_07.10.pdf |page=172 |publisher=Premier League |access-date=10 November 2025 |date=24 July 2025}} 2025/26 rule K.25 (the exact rule number changes between seasons) states "''Each Club shall provide and maintain at its Stadium an undersoil heating system for its pitch and shall ensure, so far as is reasonably possible, that the pitch is playable on the occasion of each home League Match.''"</ref> The pitch at Old Trafford has {{convert|18.4|mi}} of under-soil heating and the system at Elland Road consists of 59 miles (95 km) of piping. {{Asof|2024|09|04|alt=As of the 2024-25 season}}, clubs in the English Football League are given the choice of providing "full pitch frost covers and/or under soil heating".<ref>{{cite web |title=EFL Handbook 2024/25 |url=https://www.efl.com/documents/efl-handbook.pdf |publisher=English Football League |access-date=10 November 2025 |page=403 |date=4 September 2024}} EFL Regulation 28.9 states "''Each Home Club shall provide full pitch frost covers and/or under soil heating (the specification of which shall meet the reasonable satisfaction of The League) which shall be operated to the extent necessary to procure, so far as it is reasonably possible, that the pitch is playable on the occasion of each match. A breach of this requirement which results in the postponement or abandonment of a match shall be dealt with in accordance with Regulation 32, and not Regulation 8.4.''"</ref>
{{Asof|2011}}, the Czech First League requires all teams to play on surfaces with under-soil heating despite the league having a winter break.<ref>{{cite web|url=http://fotbal.idnes.cz/ctyri-kluby-zadaji-svaz-vyhrivany-travnik-nemaji-hrozi-jim-stehovani-1en-/fotbal.asp?c=A090603_094313_fotbal_mn|title=Čtyři kluby žádají svaz. Vyhřívaný trávník nemají, hrozí jim stěhování|language=cs|date=2009-06-04|work=idnes.cz|access-date=2011-06-15}}</ref>
In Germany under-soil heating is mandatory for division 1 and 2 Bundesliga clubs. The first ground to have it installed was the Olympic Stadium in Munich in 1972.
The old Scottish Premier League required all its clubs to have undersoil heating, but this condition was relaxed following the restructuring of Scottish football in 2013. Instead, all clubs in the top two divisions of the new Scottish Professional Football League must have grounds at the Bronze level, which allows pitch covers as an alternative to undersoil heating.<ref>{{cite news |last1=Atkinson |first1=Mark |title=Stadium and undersoil heating regulations set to be relaxed |url=https://www.scotsman.com/regions/stadium-and-undersoil-heating-regulations-set-to-be-relaxed-1594203 |access-date=10 November 2025 |work=The Scotsman |date=12 January 2013 |language=en}}</ref> {{Asof|2023}}, undersoil heating is only required for grass pitches at the Gold or Platinum levels in Scotland.<ref>{{cite web |title=SFA Club Licensing Manual 2023 |url=https://www.scottishfa.co.uk/media/9978/sfa-club-licensing-manual-2023.pdf |publisher=Scottish FA |access-date=10 November 2025 |page=30 |date=21 December 2022}} Criterion 5.6 (Technical Solutions to Maintain Field Quality) for Gold grounds requires "''Clubs shall have in place adequate irrigation and drainage systems as well as an under soil heating system. If a compliant artificial surface is in place then under soil heating is not required.''"</ref>
Several American football teams in the National Football League also have such a system installed. With American football, it is more a matter of player safety, since NFL games are never postponed on account of cold weather.
==References== {{reflist}}
== External links == * {{Commons category-inline}} * [http://www.sportvenueconstruction.com/products/under-soil-heating/ Under-soil Heating Technology at Sport Venue Construction]
Category:Association football terminology Category:Playing field surfaces