Starting point only — override below for exact project altitude
Actual installed altitude — overrides preset. ISO 2533 Patm correction.
P_atm (kPa)Calculated from altitude
101.325
Any-Two-Property Calculator
Select first known property
Numeric value for property 1
Controls chart shape & colour
Select second known property
Numeric value for property 2
Short identifier for chart
✓ Saved — View on Chart →
Calculated Properties
Saved State Points
State points appear here from two sources: Manual — calculated and saved above. Process — auto-created when you run a process in the Processes tab. Both appear on the chart.
#
Label
Source
Type
DB °C
WB °C
RH %
W g/kg
h kJ/kg
v m³/kg
No state points saved yet.
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Interactive Psychrometric Chart
Scroll to zoom · Drag to pan · Click to read · DB: −10°C to 55°C
ⓘ Chart axes are always in SI (°C / g/kg). Switch to SI to match chart values exactly.
ⓘ Desktop-optimised view. For best results use a 1280px+ wide screen.
HVAC Process Calculators
Each process auto-saves entering and leaving state points to the States tab, auto-connects them on the chart, and calculates heat transfer loads (kW / TR).
7 HVAC process models
System design airflow rate
AHU Cycle Schematic — Once Return
Run a process to generate schematic.
Process Chain Summary
#
Process
Airflow L/s
ṁ kg/s
Enter DB °C
Leave DB °C
Enter h kJ/kg
Leave h kJ/kg
Enter W g/kg
Leave W g/kg
Q_s kW
Q_l kW
Q_t kW
TR
Engineering Advisor
Complete a process for advice.
PROTo reorder processes — delete from the step you want to change and re-enter in the correct order. Drag-and-drop AHU sequencing and multi-zone analysis are available in DENOVA Psychrometrics Pro.
Manual Chart Connections
Manually draw arrows between state points on the chart. Use this for points saved in the States tab. Note: the process chain above auto-creates connections — no need to add them manually here.
⚠ CONN — Save at least 2 state points first.
From
To
Type
Δh kJ/kg
Two-Stream Adiabatic Mixing
Stream 1 — Outside Air
Outdoor dry bulb
Outdoor relative humidity
Outside air flow rate
Stream 2 — Return Air
Return air dry bulb
Return air humidity
Return air flow rate
Apparatus Dew Point & Bypass Factor
Entering air dry bulb
Entering air humidity
Leaving air dry bulb
Typical 88–95%
For pressure correction
Data Export
JSON — Full Psychrometric Data
All 18 properties per state point. Use to reload this session or pass data to other DENOVA tools.
CSV — State Points (SI)
All state points in SI units. Suitable for spreadsheet review, documentation, or manual import.
CSV — State Points Summary
All saved state points in a simple spreadsheet-ready format. Use for documentation or review.
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Save points and run processes to generate report.
Point Type Legend
Each type gives the point a unique shape and colour on the psychrometric chart. Process calculators auto-assign types — you can override manually.