A pressure reading of 10 inches water column is approximately equal to how many psig?

A pressure reading of 10 inches water column is approximately equal to how many psig?

• A. 0.10 psig
• B. 0.25 psig
• C. 0.50 psig
• D. 0.36 psig

Answer: (D)

Converting inches of water column to psi is how we interpret low-pressure HVAC readings. For water, 1 inch of water column is about 0.0361 psi. Multiply by 10, you get 0.361 psi, which rounds to roughly 0.36 psig. Since psig is gauge pressure (above atmospheric pressure), this reading makes sense for a ten-inch water column. The other options correspond to about 7, 14, or 3 inches of water, which don’t match ten inches, so 0.36 psig is the best fit.

Converting inches of water column to psi is how we interpret low-pressure HVAC readings. For water, 1 inch of water column is about 0.0361 psi. Multiply by 10, you get 0.361 psi, which rounds to roughly 0.36 psig. Since psig is gauge pressure (above atmospheric pressure), this reading makes sense for a ten-inch water column. The other options correspond to about 7, 14, or 3 inches of water, which don’t match ten inches, so 0.36 psig is the best fit.