If you work in HVAC, civil engineering, or building science, you know the psychrometric chart is your best friend—until you need to plot 50 different data points. Doing it manually with a green glass ruler and a pencil is a rite of passage, but in today’s fast-paced world, efficiency is king.
That is where the comes in.
Head to your favorite HVAC forum or university extension site, grab a trusted file, and test it against a known chart point (e.g., 80°F DB / 67°F WB should give you about 50% RH). If it matches, you just saved yourself $500 on software. Do you have a favorite free Excel psychro sheet? Share the link in the comments below to help fellow engineers stay cool and dry! psychrometric calculator excel free download
