Bar (unit) (symbol: cbar), and millibar (symbol: mbar or mb). The notation bar(g), though deprecated by various bodies, represents gauge pressure, i.e., pressure in bars above ambient or atmospheric pressure. The bar is defined using the SI derived unit, pascal: ≡ 100,000 Pa ≡ 100,000 N/m. Thus, is equal to: and 1 bar is approximately equal to: Notes: The word "bar" has its origin in the Greek word (), meaning weight. The unit's official symbol is bar; the earlier symbol b is now deprecated and conflicts with the use of b denoting the unit barn, but it is still encountered, especially as
Blower door SI pressure measurement unit Pascal (pa). Imperial measurement units are commonly water column inches (WC Inch or IWC). The conversion rate is 1 WC inch = 249 Pa. Examples below use the commonly accepted pressure of 50pa which is 20% of 1 IWC. This is the first metric that results from a Blower Door Test. The airflow, (Imperial in Cubic Feet / minute; SI in liters / second) at a given building-to-outside pressure differential, 50 pascal (Q). This standardized single-point test allows for comparison between homes measured at the same reference pressure. This is a raw number reflecting only the