Low Cost, Manual Regeneration Air Dehydrator

Features & Benefits

  • Provides cost effective dry air at 0.5 psig (34.5 mbar)
  • Prevents vapor, dust, and small particles from entering small systems
  • Improves transmission reliability by protecting against reflection
  • Dry, clean, positive pressure extends equipment lifetime
  • International capability
  • • 120/230 volt 50/60 Hz operation
  • • Selectable English or SI calibration
  • Simple to install and operate
  • Brackets supplied for rack mounting, wall mounting, and feet for shelf or bench top use
  • Convenient front panel access for easy replacement of desiccant canister
  • Low energy usage
  • Quiet
EDH-4 Dehydrator with 19" rack mounting brackets.

EDH-4 Dehydrator with 19″ rack mounting brackets.

EDH-4 dehydrator, 19" rack mount, dimensions

EDH-4 dehydrator, 19″ rack mount, dimensions


EDH-4 Datasheet EDH-4 Manual

The EDH–4 dehydrator addresses the need for a low cost, non-regenerating air dehydrator for pressurizing small volume waveguides and coax. It is especially suited for C, X, Ku, and Ka band applications.
The output pressure is 0.5 psig (34.5 mbar) with a maximum flow rate of 6.0 scfh (2.8 lpm). It is intended for use in systems smaller than 18 cubic feet (510 liters).
The EDH–4 indicates pressure and status on a bright red LED display. Display parameters are user selectable in English or SI units.
A cut out in the front panel allows for easy inspection of the color indicating desiccant, which begins bright orange when dry and transitions to white over time. Additionally, the dehydrator will alarm after a preset number of compressor hours to indicate that the desiccant should be inspected and possibly changed.
When the time comes to change the desiccant, the front panel is easily opened exposing the desiccant canister and allowing for simple removal for replacement, or optionally, manual regeneration. No special tools are required.



Dehydrator Type Non-Programmable, Single Canister, Desiccant Dehydrator
Regeneration Method Manual Regeneration or Replacement
Regeneration Indication Desiccant Color Change and Compressor Run Time
Outlet Dew Point -40°C (New or newly regenerated desiccant) to -10°C (Desiccant requiring regeneration or replacement)
Outlet Pressure 0.3 psig – 0.5 psig (34.5 mbar)
Flow Rate 6.0 scfh (2.8 lpm)
Capacity 18 scf (510 liters) standard, 45 scf (1,274 liters) max
Discharge Port Single Port: 1/8 inch NPT female fitting, 1/4 inch (6.4 mm) hose barb
Relief Valve Pressure 1.8 psig (124 mbar)
Supply Voltage 100 – 240 VAC Auto-select
Typical dew point Below -40° C
Pressure 0.5 psig standard
Flow Rate 6.0 scfh standard
Supply Voltage 100 – 240 VAC 50/60 Hz, Auto-select
Power Requirement @120 VAC: 22 watts maximum; 8.3 watts minimum
Reliability MTBF: 100,000 hours


Air Pressure Indication Digital Display (English or SI)
Data Display Pressure, Estimated Desiccant Capacity Remaining, Error Codes
Communications Port Alarm Relay
Alarm Relay Capacity 2 Amp @ 30 VDC
Relay Connection 6-position terminal block


Dimensions 5.22″ × 11.63″ × 7.0″
(133 mm × 295 mm × 178 mm)
Weight 7.8 pounds (3.54 kg)
Mounting 19″ or 13 1/2″ Rack (3U space required),
wall mount, shelf or table top


Storage Temp -40°C to 60°C
Operating Temp 0°C to 55°C


Order Number Description
18021 EDH–4 Low Cost Air Dehydrator (Revision A)
25016 Replacement Desiccant Canister for EDH-4 (Revision A)
18138 Replacement Desiccant, 32 ounces (0.95 liters)