Cleveland Controls DFS-221 Switch

The Cleveland Controls DFS-221 Air Flow Switch is a high-precision, factory-set differential pressure switch designed for air proving in demanding HVAC and energy management systems. Engineered to detect positive, negative, or differential pressure, this SPDT air pressure sensing switch is factory-calibrated to operate on a pressure rise at 0.05" ± 0.02" w.c.. Its non-adjustable design ensures consistent performance in duct heaters, ovens, and sequence-sensitive applications where tampering must be avoided. The rugged plated housing contains a durable silicone diaphragm compatible with air and non-corrosive combustion by-products, maintaining a maximum pressure rating of 0.5 psi.

For efficient field integration, the DFS-221 features 1/4" barbed sample line connections and standard 1/4" 90° male quick-connect spade terminals. This HVAC airflow proving switch is rated for 120-277Vac and provides reliable switching for pilot duty loads. When installing, ensure the diaphragm is mounted in a vertical plane to maintain the specified set point. This unit is an essential component for furnace draft proving and airflow monitoring in confined or restricted-access surface-mount installations.

• Fixed Set Point Accuracy: Pre-calibrated at 0.05" w.c. to ensure reliable system safety without the risk of field adjustment errors.
• Versatile Pressure Sensing: Capable of monitoring positive, negative, or differential air pressure across a wide variety of HVAC equipment.
• Contractor-Friendly Installation: Equipped with dual 1/4" barbed fittings and 1/4" spade terminals for rapid wiring and tubing connection.
• Durable Construction: Features a zinc-plated steel housing and a silicone diaphragm designed for long-cycle life in temperatures ranging from -40°F to 180°F.

• Can I mount the DFS-221 in any orientation? For the switch to trip at the stated 0.05" w.c. set point, it must be mounted with the diaphragm in a vertical plane.
• Is this switch compatible with flue gases? Yes, it is designed for use with air and combustion by-products that do not degrade silicone.
• What size tubing does the DFS-221 require? The unit features 1/4" barbed connections suitable for standard flexible tubing.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.