Water Penetration Testing Units

As in most professions there is jargon.  Here is guide to the most common jargon related to air tightness and water testing. 

Pressures

Pascals – the international unit of pressure. It takes 6894.75 Pascals to equal 1 psi.  Windows are often put under 200 Pascals or more negative air pressure when they are tested for water infiltration in order to simulate wind driven rain.

“ w.c. (Inches water column) – a common engineering unit of pressure used in the U.S., used often in HVAC applications.  248 Pascals equal 1” w.c.

psf (pounds/sq foot) – another common engineering unit of pressure used in the U.S. 48 Pascals equals 1 psf 

psi (pounds/sq inch)- the most familiar unit of pressure in the U.S. What we use to gauge the pressure in our tires.  This unit is often used for setting the water pressure on the spray rack or gun. 

Weight and Volume 

Grams - the metric unit used to describe the total amount of water that is allowed to “leak” in during some types of water tests. Never more than 14 grams.    

Oz. (ounces) – the English unit used to describe the total amount of water that is allowed to “leak” in during some types of water tests.  Never more than 1/2 oz.    

ml – (milliliter) – the metric unit of volume used to describe the total amount of water that is allowed to “leak” in during some types of water tests. Never more than 15 ml.  

1 gram of water ~ 1 ml of water ~ 0.03 oz. of water. Because water has a density of 1, a gram of water is equal to a ml of water.  

Go to "Blower Door & Air Leakage Units" or Go to "Test Type Descriptions"