The only way you could make this unit work with rectangular ducts would be to get adapters to go from rectangular duct to round duct then another adapter to go from round back to rectangular. As the staff member indicated, there are other fans that are intended for use with rectangular ductwork.
Tjernlund Booster Fan — 8in., 300 CFM, 120V, Model# EF-8

This is a carousel with one large zoomable image and a track of thumbnails on the left. Select any of the thumbnail buttons to change the zoomable image on the right. If a thumbnail is a video or 360 degree image thumbnail, or the last thumbnail in the list, the button will open the product media modal.

Click or Tap image to Zoom
- Powerful Airflow (Up to 325?CFM): Delivers robust airflow in 8" ducts, helping overcome static pressure drops and ensuring even heating or cooling in distant or underserved areas of your home.
- Heavy-Duty Galvanized Steel Housing: Built for durability and heat resistance (up to 150?°F), this robust housing protects the motor and blade assembly and withstands long-term use in HVAC systems.
- Metal Fan Blade with C-Frame Motor: Equipped with a high-performance metal fan blade and C-frame motor architecture for consistent speed and better pressure-handling capability than plastic-blade models.
- Low Power Consumption: Operates on only 56?W (1.1?A at 120?V), keeping energy usage minimal while still providing significant airflow gains—a more efficient option than running an oversized HVAC blower.
- Minimal Maintenance & Simple Control Options: Designed to work with standard HVAC filters so no blade cleaning is needed. You can control the fan manual on/off, use Tjernlund’s optional SC?1 speed controller, or automate operation with a duct-mounted airstat sensor.
See full description
Recently Viewed Items
This is a carousel with auto-rotating slides. Activate any of the buttons to disable rotation. Use Next and Previous buttons to navigate, or jump to a slide with the slide dots.



