Hi-Velocity CU-51-EC-BU Air Handler

The CU-51-EC-BU is a compact CU-51 Cube-series air handler with a backward-curved centrifugal fan and 24 V control board — designed for space-constrained applications such as attics, crawl spaces, garages and single-zone space heating/cooling. Fits 1.5–2 ton of cooling capacity.

Key features

• Compact cube cabinet — installs in Hi-Boy, horizontal or counter-flow positions
• Backward-curved centrifugal fan for consistent static pressure
• Standard 24 V circuit board — prioritizes thermostat calls, controls heating/cooling output and fan speed
• Hydronic coil connections: 3/4" I.D. copper sweat
• Ducted or unducted operation; steam humidifier compatible (18" downstream of supply collar)
• Rear return-air access; single-side service access
• CSA / UL / AHRI / DOE compliant

Specifications

Applications

The Cube Series suits attic and crawl-space installations, garage heaters, single-room add-ons and other space-constrained retrofit jobs — anywhere a full HE-Z or LV cabinet won't fit but rear-return, high-static-pressure air delivery is still required.

Documents

• Cube EC Installation Manual (PDF)
• HE-Z Standard Brochure (PDF)
• HE-Z Engineering Specifications (PDF)