SEMCO Website Login
SEMCO Rectangular to Round & Oval Conversion Calculator
SEMCO'S MicroLink™ Rectangular to Round and Oval Conversion Calculator is designed to aid in the conversion of rectangular HVAC layouts to round and oval duct and fittings. Enter the rectangular size shown on drawings and it will calculate the equivalent round diameter and list SEMCO's recommended round diameter and oval major/minor. The History button will give you a printable listing of all sizes calculated during the current session. When you start up your next session, you will be prompted to clear the history for the last session.
In the example above, rectangular duct with a width of 52" and a height of 18" with a 1" Dual Wall converts to a 32" round or 53" major and 18" minor as recommended by SEMCO. For oval sizes with a major greater than 70", only Oval Longitudinal Seam is available.
Note: If the program does not have a history option, or does not look like the one above, you may have to adjust your computer settings to 'Small Fonts' in the 'Settings' menu of the 'Control Panel.'
Click here to Download.
MicroLink™ is a registered trademark of SEMCO.