Product Description
APS Atmosphere Air Pressure Switch is a compact, fixed-set-point pressure sensing switch with an integrated timer module, ideal for controlling inline fans based on duct pressure levels. Designed for accurate operation and durability, it detects rising air pressure and activates equipment such as booster fans with precise timing control. This unit features a built-in 10-minute ON / 15-second OFF cycle recycling delay timer, making it perfect for ventilation systems where airflow demand varies.
Brand: Atmosphere
Model: APS
Set Point: 0.05" ± 0.02" w.c.
Switch Type: SPST-NO (Single Pole Single Throw - Normally Open)
Timer: 10-minute ON / 15-second OFF delay cycle
Power: 120V AC ±10%, 50/60 Hz
Shipping Weight: 1.2 lbs
Free shipping on orders over $250
Product Benefits
- Automatically activates booster fans based on air pressure rise
- Built-in timer module ensures controlled fan cycling
- Pre-calibrated set point simplifies installation with no field adjustments
- Compact and rugged design for long-term HVAC performance
Key Features
- Fixed Pressure Set Point: Activates at 0.05" ± 0.02" w.c. with optional screw adjustment
- Recycling Delay Timer: 10-minute ON and 15-second OFF for sustained operation
- Wide Temperature Range: Operates from -40°F to 140°F
- Solid-State Relay Output: Rated for 8A resistive or 1/8 hp inductive loads
- Tool-Free Connection: Barbed tubing connection accepts 1/8"–1/4" flexible tubing
Technical Specifications
| Specifications | |
|---|---|
| Model | APS |
| Set Point | 0.05" ± 0.02" w.c. |
| Switching Differential | 0.02" ± 0.01" w.c. |
| Max Current Rating | 8 Amps resistive / 1/8 hp inductive |
| Voltage | 120V AC ±10% |
| Timer Cycle | 10 minutes ON / 15 seconds OFF |
| Operating Temp | -40°F to 140°F (-40°C to 60°C) |
| Enclosure Dimensions | 6.15" x 4.41" x 3.34" |
| Shipping Weight | 1.2 lbs |
Application Examples
- Triggers inline duct booster fans when air pressure increases
- Ideal for HVAC return/exhaust ducting in residential and commercial spaces
- Used in interlock control systems based on airflow activity
- Applicable for dryer booster fans, range hoods, and ERV/HRV systems
Installation Tips
- Mount the unit vertically on a stable surface using provided screw holes
- Connect the sample line to the high-pressure side of the duct
- Use flexible 1/8" to 1/4" tubing for pressure input
- Wire into 120V AC line and connect output to fan or relay circuit
- Ensure power is disconnected before installation or service
Frequently Asked Questions
Q: What triggers the APS switch to turn on?
A: When air pressure rises to approximately 0.05" w.c., the internal switch closes and activates the output circuit.
Q: Is the set point adjustable?
A: The factory set point is fixed at 0.05", but APS-A variants allow adjustment up to 0.22" w.c.
Q: Does the APS have a built-in timer?
A: Yes, it includes a recycling timer that turns the fan on for 10 minutes and off for 15 seconds repeatedly.
Q: Can I use it with a 277V system?
A: The internal relay supports up to 277V AC switching, but the control power must be 120V AC.
Q: What kind of wiring terminals does it use?
A: Screw-type terminals compatible with 12–24 AWG wire.
Q: Is this unit UL or ETL approved?
A: Yes, it is ETL approved for safety compliance.
