Lithini ixabiso lika-U lefestile okanye ucango?

Kumxholo wezakhiwo ezisebenza ngamandla, "ixabiso le-U" lidla ngokubhekisa ekuqhubeni kwe-thermal yemathiriyeli okanye icandelo, ekwaziwa ngokuba yi-U-factor okanye i-U-value, engumlinganiselo wokukwazi ukudluliselwa kwesixhobo. ubushushu ngeyunithi nganye yomahluko weqondo lobushushu ngeyunithi yexesha ngeyunithi yendawo yomphezulu, kwaye idla ngokubonakaliswa ngeeyunithi ze-W/m²-K (iiwatts ngeskwere semitha ngekelvin).

Ixabiso eliphantsi le-U, ngcono ukugquma kwezinto kunye nokusebenza ngakumbi ekumiseni ukuhanjiswa kobushushu, ngaloo ndlela kuphuculwe ukusebenza kakuhle kwamandla kwesakhiwo. Kuyilo lolwakhiwo olusebenza ngamandla, ukukhetha izinto ezinexabiso eliphantsi le-U kubalulekile ekunciphiseni ukusetyenziswa kwamandla okufudumeza nokupholisa.

Nangona ixabiso le-U (okanye i-U-factor) lihlabathi lonke, ixabiso le-U lingabonakaliswa kwiiyunithi ezahlukeneyo. Kumazwe amaninzi, ixabiso le-U libonakaliswa kwiiyunithi ze-SI.

Kumazwe amaninzi, ixabiso le-U libonakaliswa njengeeyunithi ze-SI,

W/(m2⋅K):

EUnited States, ixabiso le-U libonakaliswa njengeeyunithi ze-thermal zaseBrithani (Btu) ngeyure-square feet-degrees Fahrenheit.

Btu/(h⋅ft2⋅°F)

Kulo lonke olu xwebhu, ixabiso le-U libonakaliswa njenge-SI ngaphandle kokuba kuchazwe ngenye indlela. Ukuguqula i-SI kumaxabiso aqhelekileyo ase-US, yahlula ngo-5.678.

I-Thermal conductivity iphantsi kwiindawo ezikhuselwe kakuhle zesakhiwo kwaye ziphezulu kwiindawo ezingakhuselekanga kakuhle. U-ixabiso lithathela ingqalelo ilahleko ngenxa yemitha yobushushu, ukuhanjiswa kobushushu, kunye nokuqhutywa kobushushu.

Nangona iiyunithi ze-thermal conductivity zifana ne-coefficients yokudlulisa ubushushu, i-thermal conductivity iyahluka ekubeni i-coefficients yokudlulisa ubushushu isetyenziselwa ukuchaza ukuhanjiswa kobushushu kumanzi, ngelixa ukuhanjiswa kwe-thermal kusetyenziselwa ukwenza lula i-equations ngeendlela ezahlukeneyo zokumelana ne-thermal.

Ichazwa ngolu hlobo lulandelayo:

φ = A × U × (T1 - T2) apho Φ ukuhanjiswa kobushushu kwi-watts, i-U yi-thermal transmittance, i-T 1 yiqondo lokushisa kwelinye icala lesakhiwo, i-T 2 yiqondo lokushisa kwelinye icala lesakhiwo. , kunye no-A yindawo ekwimitha yesikwere.

I-thermal transmittance yeendonga ezininzi kunye nophahla ingabalwa ngokusebenzisa i-ISO 6946 ngaphandle kokuba kukho i-metal bridging insulation, apho i-ISO 10211 ingasetyenziswa. Kwimigangatho emininzi ephantsi, i-ISO 13370 ingasetyenziswa. Kwiifestile ezininzi, ukuhanjiswa kwe-thermal kungabalwa kusetyenziswa ISO 10077 okanye ISO 15099.

I-ISO 9869 ichaza indlela yokuvavanya ukuhanjiswa kwe-thermal yesakhiwo. Ukukhethwa kwezinto eziphathekayo kunye nomgangatho wofakelo kunempembelelo ebalulekileyo ekusebenzeni kwe-insulation yefestile. Ukuqulunqa kunye nokutywinwa kabini kwenkqubo yefestile zezona ndawo zibuthathaka zokufakelwa kwefestile.