A cikin mahallin gine-gine masu amfani da makamashi, "U-darajar" yawanci yana nufin yanayin zafi na wani abu ko bangaren, wanda kuma aka sani da U-factor ko U-value, wanda shine ma'auni na ikon abu don canjawa wuri. zafi kowane raka'a na bambancin zafin jiki kowace naúrar lokaci ta hanyar naúrar fili, kuma yawanci ana bayyana shi a cikin raka'a na W/m²-K (watts kowace murabba'in mita kowace kelvin).
Ƙananan darajar U-darajar, mafi kyawun rufin kayan aiki kuma mafi tasiri shi ne a dakatar da canja wurin zafi, don haka inganta ingantaccen makamashi na ginin. A cikin ƙirar gine-gine mai amfani da makamashi, zabar kayan da ƙananan U-daraja yana da mahimmanci don rage yawan amfani da makamashi don dumama da sanyaya.
Kodayake U-darajar (ko U-factor) na duniya ne, ana iya bayyana ƙimar U a cikin raka'a daban-daban. A yawancin ƙasashe, ana bayyana ƙimar U a cikin sassan SI.
A yawancin ƙasashe, ana bayyana ƙimar U azaman raka'o'in SI,
W/(m2⋅K):
A cikin Amurka, ana bayyana darajar U azaman raka'o'in thermal na Biritaniya (Btu) a cikin sa'a-sa'a-square ƙafa-digiri Fahrenheit.
Btu/(h⋅ft2⋅°F)
A cikin wannan daftarin aiki, ana bayyana ƙimar U a matsayin SI sai dai in an faɗi. Don canza SI zuwa ƙimar al'ada ta Amurka, raba ta 5.678.
Ƙunƙarar zafin zafi ya yi ƙasa sosai a cikin ɓangarorin ginin da aka keɓe kuma mafi girma a cikin ɓangarorin da ba su da kyau. u-darajar tana yin la'akari da asara saboda zafin zafin radiation, zafi zafi, da kuma tafiyar da zafi.
Ko da yake raka'a na thermal conductivity sun kasance daidai da ma'auni na canja wurin zafi, zafin zafin jiki ya bambanta a cikin cewa ana amfani da ma'aunin zafi don bayyana canjin zafi a cikin ruwaye, yayin da ake amfani da wutar lantarki don sauƙaƙe daidaito tare da nau'i daban-daban na juriya na thermal.
An siffanta shi da ma'auni mai zuwa:
φ = A × U × (T1 - T2) inda Φ shine canjin zafi a cikin watts, U shine watsawar thermal, T 1 shine zafin jiki a gefe ɗaya na tsarin, T 2 shine zafin jiki a gefe na tsarin. , kuma A shine yanki a cikin murabba'in mita.
Ana iya ƙididdige yawan watsawar thermal na yawancin bango da rufin ta amfani da ISO 6946 sai dai idan akwai rufin gadar ƙarfe, a cikin wannan yanayin ana iya amfani da ISO 10211. Ga mafi yawan benayen ƙasa, ana iya amfani da ISO 13370. Ga yawancin windows, ana iya ƙididdige watsawar thermal ta amfani da ISO 10077 ko ISO 15099.
TS EN ISO 9869 yana bayanin yadda ake gwada gwajin yanayin watsawar tsarin. Zaɓin kayan aiki da ingancin shigarwa suna da tasiri mai mahimmanci akan tasiri na rufin taga. Ƙaddamarwa da rufewa sau biyu na tsarin taga sune ainihin wuraren da ke da rauni na rufin taga.
Lokacin aikawa: Agusta-15-2024