This Standard specifies the calculation of thermal transmittance through the central part of glazing 1) used for building apertures (U value).<\/p>\n
\nThe combined edge effects due to the thermal bridge of insulating glass spacer and of vacuum glass edge seal, and of the window frame are not included 2).<\/p>\n
\nThese calculations are intended to enable the heat loss through a window glass of building estimated from the thermal transmittance through the central part of glazing, together with heat losses through the opaque elements of the building, and used to determine the capacity of the heating or cooling plant.<\/p>\n
\nIn addition, U values for other purposes can be calculated using the same procedure, in particular for predicting:<\/p>\n
\na) heat gains in summer by conduction;<\/p>\n
\nb) condensation on glass surfaces;<\/p>\n
\nc) seasonal heat loss through window glasses in determining overall energy use in buildings;<\/p>\n
\nd) contribution of the amount of absorbed solar radiation in determining total solar energy transmittance.<\/p>\n
\nThe calculations have been made as simple as possible consistent with accuracy.<\/p>\n
\nNOTE The International Standard corresponding to this Standard and the symbol of degree of correspondence are as follows.<\/p>\n
\nISO 10292:1994 Glass in building\u2014Calculation of steady-state U values (thermal transmittance) of multiple glazing (MOD)<\/p>\n
\nIn addition, symbols which denote the degree of correspondence in the contents between the relevant International Standards and JIS are IDT (identical), MOD (modified), and NEQ (not equivalent) according to ISO\/IEC Guide 21-1.<\/p>\n
\nNote 1) Glazing is as follows.<\/p>\n
\na) Glazing mainly manufactured from soda lime silicate glass by continuous moulding process.<\/p>\n
\nGlass having diffuse transmissivity, such as figured glazing, is included.<\/p>\n
\nb) Glazing in a) of which the surface is processed with optical coating of wavelength-selective reflection such as a heat reflecting glass in wavelength region of solar radiation, and a reflecting glass (Low-E glass) in wavelength region of thermal radiation at ambient temperature such as a low radiation glass.<\/p>\n
\nc) Laminated glass, tempered glass, heat-strengthened glass, tempered fire resistance glass, etc. intended for fragment retention, strength enhancement, etc., on which the process of a) or b) is given.<\/p>\n
\nd) Insulating glass and vacuum glass using the flat glass of a) to c), except those containing lattice, etc. in a gas space.<\/p>\n
\nNote 2) When calculating the thermal transmittance of whole window, the edge effects due to the thermal bridge of insulating glass spacer and of vacuum glass edge seal, and of the window frame should be considered (see JIS A 2102-1 [1]).<\/p>\n
\n[1] JIS A 2102-1 Thermal performance of windows and doors\u2014Calculation of thermal transmittance\u2014Part 1: General<\/p>\n","protected":false},"excerpt":{"rendered":"
Calculation of thermal transmittance of glazing<\/b><\/p>\n\n\n
\n Published By<\/td>\n Publication Date<\/td>\n Number of Pages<\/td>\n<\/tr>\n \n JIS<\/b><\/a><\/td>\n 2019-03-20<\/td>\n 31<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":660135,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[1158,2655],"product_tag":[],"class_list":{"0":"post-660121","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-81-040-20","7":"product_cat-jis","9":"first","10":"instock","11":"sold-individually","12":"shipping-taxable","13":"purchasable","14":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/660121","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/660135"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=660121"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=660121"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=660121"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}