Kumongo wezakhiwo ezonga amandla, "i-U-value" ivamise ukusho ukuqhutshwa kokushisa kwento ethile noma ingxenye, eyaziwa nangokuthi i-U-factor noma i-U-value, okuyisilinganiso sekhono lento yokudlulisa. ukushisa ngeyunithi ngayinye yomehluko wezinga lokushisa ngeyunithi yesikhathi ngeyunithi yendawo, futhi kuvame ukuvezwa ngamayunithi ka-W/m²-K (ama-watts ngemitha yesikwele nge-kelvin ngayinye).
I-U-value ephansi, ngcono ukugxilwa kwempahla futhi kuphumelela kakhulu ekumiseni ukudluliswa kokushisa, ngaleyo ndlela kuthuthukisa ukusebenza kahle kwamandla kwesakhiwo. Ekwakhiweni kwesakhiwo esonga amandla, ukukhetha izinto zokwakha ezinamavelu e-U aphansi kubalulekile ekwehliseni ukusetshenziswa kwamandla okushisa nokupholisa.
Nakuba i-U-value (noma i-U-factor) isemhlabeni wonke, amanani e-U angavezwa ngamayunithi ahlukene. Emazweni amaningi, inani le-U livezwa ngamayunithi e-SI.
Emazweni amaningi, inani le-U livezwa njengamayunithi e-SI,
W/(m2⋅K):
E-United States, inani le-U livezwa njengamayunithi ashisayo ase-British (Btu) ngehora-square feet-degrees Fahrenheit.
I-Btu/(h⋅ft2⋅°F)
Kuwo wonke lo mbhalo, amanani e-U avezwa njenge-SI ngaphandle kwalapho kushiwo ngenye indlela. Ukuze uguqule i-SI ibe amanani esintu ase-US, hlukanisa ngo-5.678.
I-Thermal conductivity iphansi ezingxenyeni ezivaleleke kahle zesakhiwo futhi iphakeme ngezingxenye ezingavalekile kahle. ama-u-values acabangela ukulahlekelwa ngenxa yemisebe yokushisa, ukuguquguquka kokushisa, nokuqhutshwa kokushisa.
Nakuba amayunithi we-thermal conductivity afana nama-coefficients okudlulisa ukushisa, ukuhanjiswa kwe-thermal kuyahluka ngokuthi ama-coefficients okudlulisa ukushisa asetshenziselwa ukuchaza ukudluliswa kokushisa oketshezini, kanti ukuqhutshwa kwe-thermal kusetshenziselwa ukwenza lula izibalo ngezinhlobo eziningana ezahlukene zokumelana nokushisa.
Ichazwa ngezibalo ezilandelayo:
φ = A × U × (T1 - T2 ) lapho Φ iwukudluliswa kokushisa ngama-watts, i-U iyi-thermal transmittance, i-T 1 izinga lokushisa ngakolunye uhlangothi lwesakhiwo, i-T 2 izinga lokushisa ngakolunye uhlangothi lwesakhiwo. , kanye no-A indawo ngamamitha-skwele.
Ukudluliswa okushisayo kwezindonga eziningi nophahla kungabalwa kusetshenziswa i-ISO 6946 ngaphandle uma kukhona i-metal bridging insulation, lapho kungasetshenziswa khona i-ISO 10211. Ezitezi eziningi eziphansi, i-ISO 13370 ingasetshenziswa. Kumawindi amaningi, ukudluliswa kwe-thermal kungabalwa kusetshenziswa i-ISO 10077 noma i-ISO 15099.
I-ISO 9869 ichaza ukuthi ungakala kanjani ngokuhlolwa ukudluliswa kwe-thermal kwesakhiwo. Ukukhethwa kwezinto zokwakha kanye nekhwalithi yokufaka kunethonya elibalulekile ekusebenzeni kokufakwa kwamafasitela. Ukufakwa kwefreyimu nokutywinwa kabili kwesistimu yamafasitela kungamaphuzu angempela abuthaka okufakwa kwamafasitela.
Isikhathi sokuthumela: Aug-15-2024