Editing Room temperature

{{Short description|Range of indoor air temperatures preferred by most people}}
{{Other uses}}
[[File:Mercury Thermometer.jpg|thumb|upright|[[Mercury-in-glass thermometer]] measuring an ''ambient temperature'' of {{convert|23|C|F}} a little above the normal "room temperature" range]]

'''Room temperature''', colloquially, denotes the range of air [[Temperature|temperatures]] most people find comfortable indoors while dressed in typical clothing. Comfortable temperatures can be extended beyond this range depending on [[humidity]], [[Room air distribution|air circulation]], and other factors.

In certain fields, like [[science and engineering]], and within a particular context, room temperature can mean different agreed-upon ranges. In contrast, '''ambient temperature''' is the actual temperature, as measured by a [[thermometer]], of the air (or other medium and surroundings) in any particular place. The ambient temperature (e.g. an unheated room in winter) may be very different from an ideal ''room temperature''.

Food and beverages may be served at "room temperature", meaning neither heated nor cooled.

==Comfort temperatures==
{{main|Thermal comfort}}
Comfort temperature is interchangeable with neutral temperature in the scientific literature, which can be calculated through regression analysis between thermal sensation votes and indoor temperature. The neutral temperature is the solution of the resulting regression model by setting the thermal sensation vote as zero. ''[[The American Heritage Dictionary of the English Language]]'' identifies room temperature as around {{cvt|20-22|C|F K}},<ref>{{cite book|title=The American Heritage Dictionary of the English Language|edition=5th|date=2014|url=https://ahdictionary.com/word/search.html?q=room+temperature|url-status=live|archive-url=https://web.archive.org/web/20150108000657/https://ahdictionary.com/word/search.html?q=room+temperature|archive-date=2015-01-08}}</ref> while the ''[[Oxford English Dictionary]]'' states that it is "conventionally taken as about {{cvt|20|C|F K}}".<ref>Oxford English Dictionary, Third Edition, November 2010), sub-entry at ''room''.</ref>

Ideal room temperature varies vastly depending on the surrounding climate. Studies from [[Indonesia]] have shown that the range of comfortable temperature is {{convert|24|-|29|C|0}} for local residents.<ref name="IndonesiaTemperature">{{cite journal |last1=Karyono |first1=Tri Harso |title=Predicting Comfort Temperature in Indonesia, an Initial Step to Reduce Cooling Energy Consumption |journal=Buildings |publisher=School of Architecture, Tanri Abeng University, Jalan Swadarma Raya No 58, Pesanggarahan, Jakarta 12250, Indonesia |date=21 July 2015 |volume=5 |issue=3 |pages=802–813 |doi=10.3390/buildings5030802 |doi-access=free }}</ref> Studies from [[Nigeria]] show a comfortable temperature range of {{convert|26|-|28|C|0}}, comfortably cool {{convert|24|-|26|C|0}} and comfortably warm {{convert|28|-|30|C|0}}.<ref name="Analysis of thermal comfort in Lagos, Nigeria">{{cite journal|last1=Komolafe|first1=L. Kayode|last2=Akingbade|first2=Folorunso O. A.|year=2003|title=Analysis of thermal comfort in Lagos, Nigeria|url=https://www.ajol.info/index.php/gjes/article/view/2407#:~:text=Frequency%20distribution%20of%20air%20temperatures,warm%20between%20280C%20and%20300C.|journal=Global Journal of Environmental Sciences|volume=2|pages=59–65|doi=10.4314/gjes.v2i1.2407|access-date=4 March 2021|doi-access=free}}</ref> A field study conducted in [[Hyderabad, India]] returned a comfort band of {{convert|26|-|32.45|C|0}} with a mean of {{cvt|29.23|C|F|0}}.<ref name="Hyderabad">{{cite journal |last1=Indraganti |first1=Madhavi |date=16 July 2009 |title=Using the adaptive model of thermal comfort for obtaining indoor neutral temperature: Findings from a field study in Hyderabad, India |url=https://www.sciencedirect.com/science/article/abs/pii/S0360132309001760 |journal=Building and Environment |volume=45 |issue=3 |pages=519–536 |doi=10.1016/j.buildenv.2009.07.006 |access-date=10 August 2023 |via=Elsevier Science Direct|url-access=subscription }}</ref> A study conducted in [[Jaipur, India]] among healthy young men showed that the neutral thermal comfort temperature was analyzed to be {{cvt|30.15|C|F|0}}, although a range of {{convert|25.9|-|33.8|C|0}} was found.<ref name="Jaipur">{{cite journal |last1=Dhaka |first1=Shivraj |title=Assessment of thermal environmental conditions and quantification of thermal adaptation in naturally ventilated buildings in composite climate of India |url=https://www.sciencedirect.com/science/article/abs/pii/S0360132313001200 |journal=Building and Environment |publisher=Department of Mechanical Engineering, Malaviya National Institute of Technology Jaipur, India |access-date=10 August 2023 |archive-url=https://web.archive.org/web/20220130122252/https://www.sciencedirect.com/science/article/abs/pii/S0360132314003965?via%3Dihub |archive-date=30 January 2022 |date=2014-12-13 |volume=66 |pages=42–53 |doi=10.1016/j.buildenv.2013.04.015 |url-status=live|url-access=subscription }}</ref>

People are highly sensitive to even small differences in environmental temperature. At {{cvt|24|C|F|0}}, a difference of {{cvt|0.38|C-change|F-change|2}} can be detected between the temperature of two rooms.<ref name="Battistel Vilardi Zampini Parin 2023 p.">{{cite journal |last1=Battistel |first1=Laura |last2=Vilardi |first2=Andrea |last3=Zampini |first3=Massimiliano |last4=Parin |first4=Riccardo |date=2023 |title=An investigation on humans' sensitivity to environmental temperature |journal=Scientific Reports |volume=13 |issue=1 |page= 21353|doi=10.1038/s41598-023-47880-5 |issn=2045-2322 |pmc=10695924 |pmid=38049468}}</ref> 

Owing to variations in humidity and (likely) clothing, recommendations for summer and winter may vary; a suggested{{by whom|date=October 2024}} typical range for summer is {{cvt|23-25.5|C|F|0}}, with that for winter being {{cvt|20-23.5|C|F|0}}.<ref name="airQuality">{{cite book|url=https://books.google.com/books?id=KBbHmp2yisEC&q=+ASHRAE++%22recommended+temperatures%22&pg=PA149|pages=149–151|title=Managing Indoor Air Quality|publisher=Fairmont Press|year=2011|first1=H. E.|last1=Burroughs|first2=Shirley|last2=Hansen|access-date=25 December 2014|url-status=live|archive-url=https://web.archive.org/web/20140920182354/http://books.google.com/books?id=KBbHmp2yisEC&lpg=PA149&ots=yTqUP4xIOx&dq=%2BASHRAE%20%2B%22recommended%20temperatures%22&pg=PA149#v=onepage&q=+ASHRAE%20+%22recommended%20temperatures%22&f=false|archive-date=20 September 2014|isbn=9780881736618}}</ref> Some studies have suggested that thermal comfort preferences of men and women may differ significantly, with women on average preferring higher ambient temperatures.<ref>{{cite journal |last1=Beshir|first1=MY|last2=Ramsey|first2=JD |date=March 1981|title=Comparison between male and female subjective estimates of thermal effects and sensations|journal=Applied Ergonomics|volume= 12|issue= 1|pages= 29–33|doi= 10.1016/0003-6870(81)90091-0|pmid=15676395}}</ref><ref>{{cite journal |last1=Karjalainen |first1=Sami |date=April 2007|title=Gender differences in thermal comfort and use of thermostats in everyday thermal environments|journal=Building and Environment|volume= 42|issue= 4|pages= 1594–1603|doi= 10.1016/j.buildenv.2006.01.009|bibcode=2007BuEnv..42.1594K }}</ref><ref>{{cite journal |last1=Kingma|first1=Boris|last2=van Marken Lichtenbelt |first2=Wouter|date=August 2015|title=Energy consumption in buildings and female thermal demand|journal=Nature Climate Change |volume= 5|issue= 12|pages= 1054–1056|doi= 10.1038/nclimate2741|bibcode=2015NatCC...5.1054K|s2cid=83899840 }}</ref>

In the recent past, it was common for house temperatures to be kept below the comfort level; a 1978 UK study found average indoor home temperatures to be {{cvt|15.8|C|F}} while Japan in 1980 had median home temperatures of {{cvt|13|C|F}} to {{cvt|15|C|F}}.<ref name="Mavrogianni Johnson Ucci Marmot 2021 p.">{{cite journal | last1=Mavrogianni | first1=A. | last2=Johnson | first2=F. | last3=Ucci | first3=M. | last4=Marmot | first4=A. | last5=Wardle | first5=J. | last6=Oreszczyn | first6=T. | last7=Summerfield | first7=A. | title=Historic Variations in Winter Indoor Domestic Temperatures and Potential Implications for Body Weight Gain | journal=Indoor and Built Environment | volume=22 | issue=2 | date=2021-06-02 | pages=360–375 | pmid=26321874 | doi=10.1177/1420326X11425966 | pmc=4456148 }}</ref>

Rooms may be maintained at an ambient temperature above the comfort temperature in hot weather, or below it in cold weather, if required by cost considerations or practical issues (e.g. lack of air conditioning or relatively high expense of heating.)

In the UK, the [[Offices, Shops and Railway Premises Act 1963]] provides for a minimum temperature in commercial premises, but not for a maximum temperature.

==Health effects==
{{See also|Sick building syndrome}}
[[File:Room Temperature during Heat wave in Mexico.jpg|thumb|A [[digital thermometer]] reading an ambient temperature of 36.4°C (97°F) in an unventilated room during a [[heat wave]]; a high indoor temperature can cause [[heat exhaustion]] or [[heat stroke]] in a person.]]
The [[World Health Organization]] in 1987 found that comfortable indoor temperatures of {{convert|18|–|24|C|F}} were not associated with health risks for healthy adults with appropriate clothing, humidity, and other factors. For infants, elderly, and those with significant health problems, a minimum of {{convert|20|C|F}} was recommended. Temperatures lower than {{convert|16|C|F}} with humidity above 65% were associated with respiratory hazards including allergies.<ref name="WHO 1990">{{cite book|author=World Health Organization. Environmental Health in Rural and Urban Development and Housing Unit. |title=Indoor environment : health aspects of air quality, thermal environment, light and noise. |url=https://apps.who.int/iris/bitstream/handle/10665/62723/WHO_EHE_RUD_90.2.pdf#page=17|page=17 |date=1990}}</ref><ref>{{cite news|url=https://www.bbc.co.uk/news/magazine-12606943|title=BBC News Magazine: How warm is your home|url-status=live|archive-url=https://web.archive.org/web/20171231162144/http://www.bbc.co.uk/news/magazine-12606943|archive-date=2017-12-31|work=[[BBC News]]|date=2011-03-03|last1=Lane|first1=Megan}}</ref>

The WHO's 2018 guidelines give a strong recommendation that a minimum of {{convert|18|C|F}} is a "safe and well-balanced indoor temperature to protect the health of general populations during cold seasons". A higher minimum temperature may be necessary for vulnerable groups including children, the elderly, and people with cardiorespiratory disease and other chronic illnesses. However, the recommendation regarding risk of exposure to high indoor temperatures is only "conditional". Minimal-risk high temperatures range from about {{convert|21|to|30|C|F}} depending on the region, with maximum acceptable temperatures between {{convert|25|and|32|C|F}}.{{sfn|WHO|2018
| p = [https://apps.who.int/iris/rest/bitstreams/1161792/retrieve#page=54 34]: 
4 Low indoor temperatures and insulation / 4.1 Guideline recommendations / ...  For countries with temperate or colder climates, 18 °C has been proposed as a safe and ...
}}{{sfn|WHO|2018
| p = [https://apps.who.int/iris/rest/bitstreams/1161792/retrieve#page=74 54]: 
5 High indoor temperatures / 5.4 Research recommendations / Table 5.2 Research recommendations: high indoor temp / Current state of the evidence / Few high-quality studies have assessed the direct effects of indoor temperature on health.
}}

==Definitions in science and industry==
Temperature ranges are defined as ''room temperature'' for certain products and processes in industry, science, standards, and consumer goods. For instance, for the shipping and storage of [[pharmaceuticals]], the [[United States Pharmacopeia]]-National Formulary (USP-NF) defines ''controlled room temperature'' as between {{convert|20|and|25|C}}, with excursions between {{convert|15|and|30|C}} allowed, provided the [[mean kinetic temperature]] does not exceed {{convert|25|C}}.<ref name="USP 2017">{{Cite web |url=http://www.uspnf.com/sites/default/files/usp_pdf/EN/USPNF/revisions/659_rb_notice.pdf |title=General Chapter < 659> Packaging and Storage Requirements  |date=1 May 2017 |website=[[United States Pharmacopeia]] |access-date=2018-04-04}}</ref> The [[European Pharmacopoeia]] defines it as being simply {{convert|15|to|25|C}}, and the [[Japanese Pharmacopeia]] defines "ordinary temperature" as {{convert|15|to|25|C}}, with room temperature being {{convert|1|to|30|C}}.<ref name="ECA 2017">{{Cite web |url=https://www.gmp-compliance.org/gmp-news/what-are-the-regulatory-definitions-for-ambient-room-temperature-and-cold-chain |title=What are the regulatory Definitions for "Ambient", "Room Temperature" and "Cold Chain"? |date=2 March 2017 |website=ECA Academy |access-date=2018-04-04}}</ref><ref name=Chow2007a>{{cite book|url=https://books.google.com/books?id=x9XccGzr4wIC&q=%22room+temperature%22+definition&pg=PA7|title=Statistical Design and Analysis of Stability Studies|author=Shein-Chung Chow|publisher=[[CRC Press]]|year=2007 |series=[[Chapman & Hall]]/[[CRC Press|CRC]] [[Biostatistics]] Series|access-date=4 April 2018 |isbn=9781584889069|page=7|quote=1.2.3.3 Definition of Room Temperature: According to the ''United States Pharmacopeia National {{sic|Forumlary|expected=Formulary}} (USP-NF)'', the definition of room temperature is between 15 and 30 °C in the United States. However, in the EU, the room temperature is defined as being 15 to 25 °C, while in Japan, it is defined being 1 to 30 °C.}}</ref> [[Merriam-Webster]] gives as a medical definition a range of {{convert|15|to|25|C}} as being suitable for human occupancy, and at which laboratory experiments are usually performed.<ref>{{cite book|date=2016|title=Merriam Webster's Medical Dictionary|url=http://www.merriam-webster.com/medical/room%20temperature|url-status=live|archive-url=https://web.archive.org/web/20100410144100/http://www.merriam-webster.com/medical/room%20temperature|archive-date=2010-04-10}}</ref>

==See also==
* [[Standard conditions for temperature and pressure]]
* {{anl|ISO 1}}
*[[Indoor air quality]]

==References==
{{Reflist}}
{{refbegin}}
{{cite q | Q95379102
| access-date        = 2022-11-22
| ref                = {{sfnref|WHO|2018}}
}}
{{refend}}

{{HVAC}}
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[[Category:Environmental engineering]]
[[Category:Heating, ventilation, and air conditioning]]
[[Category:Science experiments]]
[[Category:Atmospheric temperature]]