HVAC Refrigerant Charging Calculator & Live P-h Diagram | CED

HVAC Smart Charging Advisor

Tabulated Saturation Data (IIR Datum) • Fitted Compression Model (η_is = 0.72) • Bubble/Dew Glide Tracked

P_atm:

Condenser Coil Design Class (CTOA Reference):

Quick Baseline Benchmark

Enter Outdoor Ambient Temperature below to estimate typical operating pressures and normal indoor load bands.

Insert Outdoor Ambient Dry-Bulb Temp: Primary Input

°C

°F

Indoor Return Air Wet-Bulb Temp (Default 19 °C = 24 °C DB @ 50% RH):

°C WB

°F WB

Evaporator Dew-Point Sat. Temp (Rule-of-Thumb: WB + Ambient):

°C

°F

Typical Suction Pressure (Reference Only)

Estimated Low-Side Pressure

Normal Band (±2 °C WB): --

Assumes 19.0 °C (66.2 °F) Indoor WB • Charge by Subcooling/Superheat per OEM (use Med/Adv tab)

Target High Pressure

Est. Discharge Temp

Default TXV Subcooling

6.0 °C

(10.8 °F target)

Typical Air ΔT: 8–12 °C (14–22 °F)

Low-Pressure Gauge Only Mode

No high-side service port? Probe a two-phase return bend near the middle of the condenser coil to estimate T_{bub, cond}.

Expansion Metering Device:

System is fitted with a Liquid Receiver tank

Outdoor Ambient Dry-Bulb Temp:

°C

°F

Target Subcooling (Nameplate):

°C Δ

°F Δ

Target Superheat (Auto Formula):

°C Δ

°F Δ

Condenser Mid-Coil U-Bend Surface Temp:

°C

°F

Mid-Coil to Outlet Bubble Offset (Default 0.8 °C Circuit ΔP):

°C Δ

°F Δ

Liquid-Line Exit Pipe Temp:

°C

°F

Suction Pressure (LP Manifold Gauge):

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Suction Line Pipe Temp (Service Port):

°C

°F

Full Dual-Gauge Diagnostic Mode

Expansion Metering Device:

System is fitted with a Liquid Receiver tank

Outdoor Ambient Dry-Bulb Temp:

°C

°F

Target Subcooling (Nameplate):

°C Δ

°F Δ

Target Superheat (Auto Formula):

°C Δ

°F Δ

High-Side Pressure (HP Manifold Gauge):

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Liquid-Line Pipe Temp:

°C

°F

Low-Side Pressure (LP Manifold Gauge):

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Suction Line Pipe Temp (Service Port):

°C

°F

Compressor Discharge Pipe Temp (Est., η_is = 0.72):

°C

°F

Field Engineering & Regulatory Disclaimer: Indicative diagnostic guidance and modelled cycle estimates (η_is = 0.72). Always follow OEM service manual procedures, factory nameplate subcooling/superheat targets, and gravimetric weigh-in specifications. Refrigerant handling, recovery, and charging must be performed by certified personnel in accordance with EPA Section 608, EU F-Gas, or applicable national regulations, observing ASHRAE 15 / EN 378 safety protocols for Class A2L mildly flammable refrigerants.

Thermodynamic P-h Cycle Diagram
R-134a • Class A1 • GWP 1430 • Pure HFC (0 K Glide)

Actual Cycle (A→B→C→D, η_is = 0.72 or Measured T_dis) Ideal Isentropic Path (A→B_s, s = s_A) Constant-Entropy (s) Field Lines (Fitted)

Condensing Sat. Temp (T_{sat, cond}):	--
High-Side Pressure:	--
Actual Subcooling:	--
Evaporator Sat. Temp (T_{sat, evap}):	--
Total Superheat (at Service Port):	--
Condenser Temp Over Ambient (CTOA):	--
Discharge Line Temp (Model Est.):	--
Cooling Effect (q_e):	--
Cycle COP (model, η_is = 0.72):	--

Quick Baseline Benchmark

Low-Pressure Gauge Only Mode

Full Dual-Gauge Diagnostic Mode

Thermodynamic P-h Cycle Diagram 🔍 Zoom / Pan Chart R-134a • Class A1 • GWP 1430 • Pure HFC (0 K Glide)

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Thermodynamic P-h Cycle Diagram
R-134a • Class A1 • GWP 1430 • Pure HFC (0 K Glide)