MDH Series

MDH Series Desiccant
Air Dryers

0.4 to 3.2 SCFM

The MDH Series Heatless Desiccant Air Dryers are one of our smallest desiccant air dryers. It’s miniature, compact design is perfect for OEM applications and can be paired with small fractional horsepower air compressors.

  • 6 Models Available to Match Your Application Requirements and Minimize Energy Loss
  • Solid-State Timer with Built-In Memory Ensures Reliable Drying Cycles
  • Efficient Air Drying Performance from 50 PSIG to 120 PSIG Standard
    (Custom options down to 30 PSIG)
  • -40°F/C Standard Outlet Dew Point
    (ISO 8573.1 Class 2)
Standard Features:
  • Standard Outlet Dew Point
    • -40° F/C Pressure Dew Point (PDP)
  • Available Input Voltages
    • 120 VAC
    • 240 VAC
    • 12 VDC
    • 24 VDC
  • Maximum Pressure - 120 PSIG
  • Maximum Inlet Temperature - 120°F / 49°C
Optional Features:
  • Filtration Kit -
    • 5 Micron and 0.01 Micron Prefilters
    • 0.5 Micron Afterfilter
  • Filter / Regulator Kit
    • Filtration Kit (above)
    • Outlet Regulator & Gauge
General Specifications:
(SCFM @ 100 PSIG)
0.40 0.80 1.10 1.60 2.40 3.20
(SCFM @ 100 PSIG)
0.10 0.20 0.27 0.40 0.60 0.80
(SCFM @ 100 PSIG)
0.30 0.60 0.83 1.20 1.80 2.40
Inlet / Outlet Ports
1/8" 1/4"
MDH1 1.4 7.0 3.5 3.3
MDH2 1.5 10.3
MDH3 1.6 8.8 4.0 3.5
MDH4 1.9 10.1
MDH5 2.2 9.5 5.0 3.8
MDH6 3.1 11.5
MDH Series Dimensions
Multiplier Table (For INLET Pressures other than 100 PSIG):

Maximum Inlet Flow (-40° F/C PDP) = INLET Flow (above) x INLET Flow Factor (A) @ Actual Pressure (below)

Purge Flow = PURGE Flow (above) x PURGE Flow Factor (B) @ Actual Pressure (below)

Rated OUTLET Flow = Calculated Maximum Inlet Flow - Calculated Purge Flow

Actual Pressure (PSIG) 50 60 70 80 90 100 110 120
INLET Flow Factor (A) 0.32 0.43 0.56 0.70 0.85 1.00 1.09 1.17
PURGE Flow Factor (B) 0.57 0.65 0.74 0.83 0.91 1.00 1.09 1.18

MDH Series Drying Process

The MDH Series Heatless Regenerative Desiccant Air Dryers employ Pressure Swing Adsorption (PSA) technology to remove water vapor from ordinary compressed air. The 4-Way Valve directs the wet air into one of the two Desiccant Towers, where nearly all of the water vapor is removed. The ultra-dry air leaving the Desiccant Tower passes through the Outlet Shuttle Valve to the application. A Precision Purge Orifice in the Outlet Shuttle Disk allows a portion of the dry air to be redirected back through the off-ine Desiccant Tower, purging it of the accumulated moisture. The purge air then exits the unit through the 4-Way Valve and Muffler. A Solid-State Timer governs the process by controlling the 4-Way Valve.

This tool will help you size the perfect MDH Series Desiccant Air Dryer for your Compressor Output and Environmental Conditions. Simply enter the data & conditions and you'll be presented with the Part Number for the MDH Series Air Dryer that will work optimally for those conditions. We will also provide Part Numbers for the Filter Kits that were created to match that MDH Series Air Dryer perfectly.

Please use the latest version of Chrome, Firefox or Safari.
Internet Explorer not currently supported.

Required *

Filter Kit

Filter Kit

Filter Kit

Filter Kit

Please use the latest version of Chrome, Firefox or Safari.
Internet Explorer not currently supported.

Need A Custom Sized Air Dryer?

Contact Altec AIR for assistance selecting the right dryer for your application.
All you need is the required Inlet or Outlet Flow Rate, Operating Pressure, and the required Dew Point.