Resideo (Honeywell) AEL-222185 Automatic Expansion Valve – AEL 5.0 | 1-7 bar Constant Pressure, 3/8" × 5/8" ODF

Resideo (Honeywell) AEL-222185 is an automatic expansion valve (constant pressure valve). The difference from a thermostatic valve: it does not operate according to superheat but according to evaporating pressure — it keeps the evaporator pressure constant at the set value. It opens when the load drops and throttles when the load increases; this keeps the evaporator pressure, and therefore its temperature, constant.

Constant Evaporating Pressure: Dehumidification and Ice Machine Applications

According to the official Honeywell documentation, the AEL series is designed for systems with single-injection evaporators without a distributor: air conditioners, dehumidifiers, air dryers, water coolers and ice machines. Load is highly variable in these applications; while a thermostatic valve goes into hunting, a constant pressure valve keeps the evaporator stable and prevents freezing.

Technical Specifications (Official Honeywell Product Data)

• Model: Resideo (Honeywell) AEL-222185 | Valve Size: AEL 5.0
• Type: Automatic expansion valve — fixed orifice (4.75), internally equalized
• Nominal Capacity: 22.4 kW (R22) · 15.9 kW (R134a) · 15.8 kW (R404A) · 15.9 kW (R507A)
  at t₀ +4 °C / t𝒸 +38 °C, 1 K subcooling
• Evaporating Pressure Setting Range: 1 – 7 bar(a) | Factory setting 2.2 bar(a)
• Connections (ODF solder): Inlet 3/8" · Outlet 5/8"
• Max. Pressure: PS 25.5 bar(a) · test pressure PF 28 bar(a) | Max. ambient temperature 100 °C
• Dimensions: C 64 · D 47 · E 122 · F 69 mm | Weight: ≈0.28 kg — official dimension drawing in the 2nd image
• Body: Hermetic construction, stainless steel head + stainless diaphragm welded under protective gas
• Compatible Refrigerants: All CFC / HCFC / HFC refrigerants — not for use with ammonia (R717)

• 🔧 Adjustment: The factory setting is 2.2 bar(a). Turn the adjusting screw in small steps and wait for the system to stabilize; lowering the pressure lowers the evaporator temperature.
• Where it is not used: This valve is not suitable for evaporators with a distributor and multiple circuits — an externally equalized thermostatic valve (TXV) is used there.
• Cool the body with a wet cloth during brazing; keep the flame away from the adjusting spindle and diaphragm area.
• Family: The same series includes AEL 0.5 / 1.0 / 2.0 / 3.0 / 4.0 / 6 sizes; selection is made according to capacity.