R-value (insulation)

（重定向自U value）

Aerogel is an extremely efficient synthetic insulator and has a very high R-value.

The R-value is a measure of thermal resistance used in the building and construction industry. Under uniform conditions it is the ratio of the temperature difference across an insulator and the heat flux (heat transfer per unit area per unit time, $\dot Q_A$ ) through it or $R = \Delta T/\dot Q_A$ . Thermal resistance varies with temperature but it is common practice in construction to treat it as a constant value.

单词	U value
释义	U value 英语百科 R-value (insulation) （重定向自U value） The R-value is a measure of thermal resistance used in the building and construction industry. Under uniform conditions it is the ratio of the temperature difference across an insulator and the heat flux (heat transfer per unit area per unit time, $\dot Q_A$ ) through it or $R = \Delta T/\dot Q_A$ . Thermal resistance varies with temperature but it is common practice in construction to treat it as a constant value.
随便看	admittance function admittance gap Admittance matrix admittance measurement admittance measuring instrument admittance meter admittance modulation admittance,motional Admittance operator admittance parameter admittance plethysmograph admittance relay admittance relays admittance admittance spectroscopy admittance,static admittance,transducer input admittance transformation admittance triangle admittance unbalance measuring set admittance valve admittance wave admittatur admittaturs admittaunces