Inches of water, wc, inch water column (inch WC), inAq, Aq, or in H2O It is defined as the pressure exerted by a column of water of 1 inch in height at defined conditions. For example, 39 °F (4 °C) at the standard acceleration of gravity; 1 inAq is approximately equal to 249 pascals at 0 °C. Alternative standard conditions in uncommon usage are 60 °F, or 68 °F (20 °C), and depends on industry standards rather than on international standards. 1 inAq ≈ .036 psi, or 27.7 inAq ≈ 1 psi. {|