rooftop HVAC units

This article describes how to scratchbuild HO scale rooftop HVAC units.

Materials needed:


Stack 2 Legos together (these are the 2x3 size with 6 nubs). Turn upside down so the nubs become the feet of the unit. Cut 3 pieces of styrene: 2 angled sides, and a top. You can also make a shorter unit with just one Lego.


Add a small styrene rectangle to the side for an electrical disconnect. Snap some more Legos on for a temporary painting handle.


Paint units "HVAC Green". Penn Central's Jade Green will do nicely if you have that. Color the disconnect box with a silver Sharpie.


Make fans by gluing flat washers to the top, then cover the washer holes with discs made by punching thin styrene with a paper punch. Color silver with the Sharpie marker and you are done! Hoist them up to the roof and start cooling your building.

Home • Revised Dec 26 2016 RM