PsychroView User Manual

PsychroView is a free online tool for psychrometric calculations and for visualising air treatment processes in the Mollier h-x chart. It is built for engineers, building services designers and students of ventilation and air conditioning.

What PsychroView is and who it is for

PsychroView is a web psychrometric application for professional psychrometric calculations in ventilation and air conditioning. It lets you model and compare air treatment processes — heating, cooling, humidification, heat recovery and more — and plot them in an interactive Mollier h-x chart or a Carrier T-x chart (the psychrometric chart familiar from ASHRAE practice) straight in the browser. The theory behind the field is summarised in the article What is psychrometrics; for a short definition see the glossary entry psychrometrics.

As an online psychrometric calculator it needs no installation. You can run psychrometric calculations from any device at app.psychroview.com.

Who PsychroView is for

Calculations follow the ASHRAE Handbook – Fundamentals 2021; in the settings you can switch to the constants and correlations used in Czech technical literature for ventilation and air conditioning.

Availability

PsychroView and its user interface are fully localized into German, English, French, Czech and Slovak – making it suitable for international projects or as HVAC software for companies operating in multiple countries. The software includes climate data from publicly available sources, Germany (DWD) and Austria (GeoSphere), as well as a search function on sites throughout Europe.

Quick start – your first calculation

This walkthrough takes a new user from opening the application to the first point plotted in the h-x chart. The same tutorial is available as an interactive guide inside the application (it is offered in the welcome dialog; a guide for a specific process opens from the ? icon on the process card).

Step by step

1. Open the application at app.psychroview.com. Free access requires no sign-up but is limited in features. Signing up is recommended to unlock more of them.
2. Once you have signed up, you land on the Projects overview, which mainly gives you an overview of your projects and access to the example projects.
3. Click New project to enter the PsychroView workspace. On the left is a narrow vertical panel with the process (treatment) tiles, and next to it the overview panel of the processes in the project / sets.
4. Set the atmospheric pressure — the default is the standard pressure of 101.325 kPa (corresponding to an altitude of 0 m a.s.l.). For locations at higher altitudes, enter the altitude in metres and the application converts it to pressure automatically. Atmospheric pressure affects every psychrometric calculation. Set it either in the small dialog inside the chart or in the right-hand panel, section Boundary conditions.
5. Add the first process — click the Air Point tile in the process palette. A process card with a form opens.
6. Enter the inlet air conditions — temperature t [°C], relative humidity φ [%] and volume flow rate V̇ [m³/h]. You can type the values in, or take them from the climate data of the selected location in a single click (winter/summer design conditions). The application plots the point in the Mollier h-x chart immediately and derives the humidity ratio, the moist-air enthalpy, the dew point and the remaining quantities.
7. Add a treatment process — clicking a tile such as Heating or Cooling appends another step to the chain. The outlet of the preceding process automatically becomes the inlet of the new one.
8. Watch the chart — every process you add appears as a point and an arrow in the Mollier chart. The whole air treatment sequence is visible at a glance.
9. Export the results — the PDF button in the top bar generates the complete technical output: chart, summary table and detailed results of every process.

Projects

The application organises work into projects, where one project corresponds to one or more sets of calculations within a single job. You can have several projects open in one window at once — they appear as tabs in the top bar, much like browser tabs. Projects are saved to the cloud automatically. Closing a project tab only closes the project; it stays ready for further editing on the Projects overview.

Projects overview

The first tab in the bar is always Projects — the home screen of the application. It contains:

• a list of saved projects with the number of sets and processes, opened by clicking,
• example projects — ready-made sample calculations (heat recovery, cooling, humidification…) that can be browsed for free; you open them as your own editable copy,
• creating a new project and opening an .hxp file from disk.

You can return to the overview at any time by clicking its tab; it cannot be closed, as it is the base surface of the application.

Creating a project

Click the + icon to the right of the tabs in the top bar, use the New project button in the overview, or choose New project from the File menu.

Switching between projects

Click the project tab. The active project is underlined in blue.

Renaming a project

Click the pencil icon on the project tab or double-click the tab name. Type the new name and confirm with Enter, or cancel with Escape. Renaming is also possible from the Projects overview.

Closing a project

Click the × icon on the tab.

• Signed-in user — data is saved to the cloud continuously; the tab can be closed with no risk of data loss.
• Anonymous user — the application shows a warning, because the data is not stored in the cloud.

Deleting a project

Open the Projects overview and click the bin icon next to the project you want to remove. The project is deleted permanently and cannot be restored.

Scrolling the tabs

With a larger number of projects, ‹ / › arrows appear for horizontal scrolling of the tab bar.

Project information

Every project carries a set of metadata that appears in the header of the exported PDF and in the chart info panel. Expand the section by clicking the Project information header in the right-hand panel.

Project information is available to signed-in users.

Process sets – calculation variants

A set holds one process chain, that is, one set of processes and points. A single project can contain several sets — each set represents one variant of the calculation chain. Sets are colour-coded in the chart, so you can compare a variant with and without heat recovery directly in one Mollier h-x chart, or a summer and a winter operating state. Sets are also handy for visualising several operating states side by side.

Adding a set

Use the + Add set button in the set panel. The options are:

• Blank set — a new chain from scratch
• Copy of the active set — carries over the whole process configuration; ideal for comparing variants (for example different types of heat recovery exchanger or different coolant temperatures)

Set settings (the ⋯ menu, or click the name)

Undo / Redo

The application keeps a change history for the active set. Undo or redo an operation with the ← Undo / → Redo buttons or the keyboard shortcuts Ctrl+Z / Ctrl+Y.

Process palette

The palette in the left vertical panel is used to add processes to the active set. Clicking a tile appends that process type to the end of the calculation chain. New processes are always appended at the end — behind the last process in the set.

Inserting a process in the middle of the chain

Processes do not have to go at the end. Hovering between two process cards (or before the first / after the last card) reveals a + circle. Clicking it marks the insertion point; you then pick the process type in the palette — the new process is inserted exactly at the chosen position and the chain is recalculated automatically.

Customising the palette (the ⚙ icon in the palette header)

Grid: number of columns, tile size (XS / S / M / L), whether labels are shown.

Tile order and visibility:

• Drag the ⋮⋮ icon next to the process name to change the order in the palette.
• Click the eye icon to hide processes you do not need at this stage of the project.
• The Reset button restores the factory palette settings.

Overflow (+N): If more processes are active than the configured grid can hold, a +N more processes tile appears. Clicking it expands a panel with the remaining types.

Tip: Hovering over any tile shows a tooltip with the full process name and a short description — a handy quick psychrometric chart tutorial for new users.

The process card – controls and settings

Every process you add appears as a card in the left-hand process overview panel. Cards are ordered top to bottom following the calculation chain — the outlet (outlet air) of the upper card is the inlet of the card below it. Cards are linked into the calculation chain automatically.

Card header

The card header is coloured (the colour of the process or of the set) and holds the controls:

Display settings panel (⚙)

The settings panel opens directly above the card form. It lets you set:

A custom process name — name the process however you like (e.g. “HRV – plate exchanger 75%”). The name appears in the header, in the summary table and in the exported PDF.

Field visibility by category:

• Inlet air (from chain) — contextual display of the air state coming from the preceding process
• Input parameters — the parameters you enter
• Results — the calculated output values

Extended air properties (inlet / outlet sections) — hidden in the basic view; switch on only those you need for the calculation at hand:

• Dew point t_d, wet-bulb temperature t_wb
• Partial pressure of water vapour p_w, saturation vapour pressure p_ws
• Degree of saturation μ, specific volume v, air density ρ, specific heat capacity c_p, mass flow rates ṁ, ṁ_da, ṁ_w

The global default visibility of the extended properties is set in Account settings → Process property display. A setting made on an individual card overrides that global default.

Process description

The text field below the header is for notes — assumptions, data source, reference to a standard. The text appears in the exported PDF in the detail of that process.

Moving a card

Drag the card by the grip handle (⋮⋮) to the left of the header to its new position in the chain. The calculation is recalculated automatically from the point of the move.

Overriding the inlet air (disconnecting from the chain)

Instead of taking the inlet from the preceding process, any process can accept a manually entered inlet air state. Activate the function with the Override switch in the “Inlet air” section of the process card; the From chain option takes you back. The first process in the chain offers the inlet straight away — either typed in, or taken from the climate data in one click.

Typical use: testing different inlet conditions without changing the whole chain; simulating seasonal variation in an HVAC design.

Binding the inlet to a point of another process (branching)

The Point button in the inlet air section binds the process inlet to any earlier point in the chain — not just to its immediate predecessor. Side ports are available too: the side branch of a Flow Split process, or the warm air (out) port of a heat recovery unit. This is how you model branched ventilation systems (one branch downstream of a splitter continues to a reheater, the other feeds a different zone, for instance). An active binding is marked “in ←” on the card; Remove binding clears it.

Air treatment processes – detailed description

A total of 13 process types is split into four groups: Inputs, Heat, Moisture and Mixing / Split. The physics of the individual processes and how they run in the chart are covered in the article Moist air processes in the h-x chart.

Group: Inputs

Air Point

Defines the inlet air state — the start of the calculation chain. This card is typically the first in every calculation; it corresponds to point A in the classic Mollier chart.

Inputs: temperature t [°C], relative humidity φ [%], volume flow rate V̇ [m³/h]. The values can be filled in from the climate data of a location (winter ❄ / summer ☀ design conditions).

The Disconnect from previous switch — the point is plotted as a stand-alone point without an arrow linking it to the preceding process (useful for showing outdoor and exhaust air side by side).

Group: Heat processes

Air heating

Models air heating calculations — dry heating at constant humidity ratio. In the Mollier h-x chart this is a move along the line x = const towards higher enthalpy.

Input modes (always one; the rest is derived):

• Target temperature t_out [°C]
• Heater capacity Φ [kW]
• Heat loss — the heater sized to cover the specified heat loss of the space

Outputs: heater capacity Φ [kW], outlet air state. The card also holds the room balance solver for heating (see the Space balance solvers chapter).

Typical use in ventilation design: a heater in the supply branch of an air handling unit, an electric or hot-water heater in air conditioning and ventilation system design, warm-air heating.

Air cooling with condensation

Covers full air cooling calculations — including the sensible and latent parts of the capacity and the condensate calculation (the step-by-step cooling coil design procedure is covered in the article Air cooling in an AHU). It corresponds to the “cooling with condensation” process on a finned cooling coil.

Inputs:

• Target parameter — one of four modes: Temperature t_out [°C], Power Φ [kW], Condensation [kg/h], or Humidity ratio x_out [g/kg] (target dehumidification)
• Coil type — CHW (Chilled Water) with the inlet/outlet temperature of the heat-transfer medium EWT/LWT, or DX (direct expansion) with the saturated suction temperature SST
• Circuit medium (CHW) — water, propylene glycol 30/50%, ethylene glycol 30/50%, custom
• Fin pitch: coarse 3.5–5 mm / medium 2.5–3.5 mm / fine 1.5–2.5 mm
• Coolant presets — saved temperature pairs for repeated use, which you can edit and extend

Outputs: total capacity Φ [kW], sensible part Φ_s, latent part Φ_lat, SHR (Sensible Heat Ratio), condensate ṁ_cond [kg/h], ADP (Apparatus Dew Point — the effective fin surface temperature), the contact factor CF and the bypass factor BF, MTD [K], the UA coefficient [kW/K], the temperature span of the heat-transfer medium ΔT_w and its flow rate V̇_w.

The card also carries the space load solver for cooling and a read-only cooling coil check (sanity advisories on the parameters you entered).

HRV – heat recovery

Calculates heat recovery between the supply and the extract air — air-to-air heat exchange through a heat exchanger. It is one of the most used processes in the design of mechanical ventilation systems. For the definition see the glossary entry heat recovery; the calculation of effectiveness and savings is covered in the article Heat recovery (HRV).

Exchanger types:

Inputs:

• Side e1 (typically the cold supply air) — from the chain, entered manually, or bound to a point
• Side e2 (typically the warm extract air): t, φ, V̇ — or bound to an earlier point in the chain (the extract branch)
• Temperature efficiency η_T [%]
• Hygroscopic effectiveness η_w [%] — enthalpy rotary exchanger only
• Stream designation (outdoor / extract / exhaust / supply air) for the labels

Outputs: actual η_T, η_w, enthalpy effectiveness η_HRV, capacity Φ_HRV [kW], mode (pre-heating / pre-cooling), condensate on both sides, exchanger surface temperature, an automatic frost warning (t_surf < 0 °C) and a warning when the e1/e2 flow rates are markedly unbalanced.

Adiabatic cooling (adiabatic humidification)

Models adiabatic cooling — cooling by water evaporation with no heat added or removed, along the isenthalpic line. In air conditioning installations it is used as pre-cooling ahead of the cooling coil, or as evaporative cooling. See the glossary entry adiabatic cooling and the article Evaporative cooling.

Calculation modes:

• Adiabatic efficiency η_a [%] — 100% corresponds to saturation at t_wb
• Target temperature t_out [°C]
• Target relative humidity φ_out [%]

Outputs: wet-bulb temperature t_wb [°C], actual efficiency η_a, water consumption [kg/h].

Heat load

Simulates internal heat gains (people, lighting, equipment) — sensible heat added without changing the humidity ratio of the air. It corresponds to the process taking place in the room in an air conditioning design.

Input: heat input Φ [kW].

Heat loss

Dry heat loss through the building envelope — sensible heat removed without condensation. Input: capacity Φ [kW]. If the outlet temperature drops below the dew point of the inlet air, the application shows a warning. Condensation in building structures and how to prevent it are covered in the article Water vapour condensation in buildings.

Group: Moisture processes

Air humidification

Complete humidification calculations — three different ways of humidifying air. Steam, adiabatic and ultrasonic humidification are compared in the article Air humidification in AHUs.

Inputs: target relative humidity φ [%] or target humidity ratio x [g/kg]; steam temperature t_s [°C] and steam quality q_s for the steam variants; water temperature t_w for water humidification. The slope of the process in the h-x chart is set by the quantity dh/dx (the specific enthalpy of the humidifying medium).

Outputs: humidification capacity Φ [kW], humidification flow rate ṁ_evap [kg/h], steam enthalpy h_s [kJ/kg]. The card also holds the combined Heat + humidify solver (see Space balance solvers).

Humidity load

Isothermal moisture addition — models the moisture produced by people, food or wet surfaces. Enter it either as a moisture flow rate [g/h] or as the required increase in humidity ratio Δx. Outputs: actual moisture flow rate, Δx, latent capacity Φ_lat [kW].

Sorption dehumidification

Adsorption of water vapour on a solid desiccant (silica gel, molecular sieves) — see the glossary entry desiccant dehumidification and the article Desiccant dehumidification. The calculation gives the minimum power needed to regenerate the desiccant. Inputs: target φ [%] or x [g/kg]. Outputs: moisture removed [kg/h], adsorption power [kW], regeneration power [kW], outlet temperature (adsorption releases heat).

Group: Mixing and split

Mixing of 2 streams

Mixing of two airstreams — a basic operation in every ventilation and air conditioning calculation (mixing outdoor and recirculated air).

Inputs:

• Stream 1 — automatically from the preceding process, manually (disconnected from the chain), or bound to a point
• Stream 2 — manually: t, φ, V̇, or bound to an earlier point in the chain (e.g. the side branch of a Flow Split — recirculation)

Outputs: mixed air state (t, φ, x, h, ρ, V̇), condensate when the mixture is subcooled below its dew point [kg/h].

Mixing of 3 streams

Mixing of three airstreams — an extension of the previous process for three-component mixing calculations (e.g. outdoor + recirculated + extract air). Inputs: t, φ, V̇ for each of the three streams. Outputs: mixed state, condensate [kg/h].

Flow split

Splitting one airstream into two branches by a given ratio — typically in ventilation ductwork or as a recirculation take-off.

Input: branch 1 fraction.

Outputs:

• Branch 1 — continues as the outlet into the next process in the chain
• Branch 2 — the secondary branch, shown in the chart and the table; the inlet of another process can be bound to it (binding to a point)
• Flow rates of both branches [m³/h] and [kg_da/h]

Space balance solvers

The Cooling, Heating and Humidification cards contain integrated deterministic solvers that derive the required processes from the room balance automatically — with no manual iteration.

Space load solver (Cooling)

Enter the target band for the space (t_min–t_max, φ_min–φ_max), the heat gain — either as a total or split into sensible + latent parts — the moisture production [g/h], the permitted ΔT between supply and space and the coolant temperature range. The solver determines the required supply state, the temperature span of the heat-transfer medium t_c,in/t_c,out, the cooling capacity, the condensate, the SHR and any reheat needed. The Apply button writes the calculated processes into the chain.

Room balance solver (Heating)

From the heat loss of the space, the moisture production and the target band it determines the required supply state, the heater capacity and any humidification needed (steam or adiabatic), including the steam/water flow rate.

Heat + humidify (Humidification)

A combined calculation: from the target temperature and relative humidity it determines the heater capacity, the steam flow rate and the intermediate point after heating.

The solvers report readable errors whenever the input is physically impossible (saturation exceeded, insufficient flow rate, coolant unable to reach the dew point…), together with a recommendation on what to change.

Climate data – design conditions for a location

The Climate data dialog (the button in the Boundary conditions panel, at the inlet point or in the Builder) provides design conditions for thousands of locations. You apply the chosen winter ❄ and summer ☀ condition to the inlet point of the chain in one click; at the same time the atmospheric pressure of the project is set from the altitude of the location (or directly from the source). Where design conditions come from and how humidity is measured in the atmosphere is explained in the article Meteorological psychrometrics.

Data sources

Conditions and percentiles

For every location, winter and summer design conditions are available at several severity levels (design temperature, moderate conditions, extremes), including the coincident humidity/enthalpy wherever the source provides it.

Comparing locations

The Comparison panel lets you place several locations/conditions side by side and compare the design values before making a choice.

Mollier h-x chart and Carrier T-x chart

Chart type

PsychroView supports two kinds of psychrometric chart, switchable in the chart settings (⚙ above the chart):

• Mollier h-x chart — horizontal axis = humidity ratio x [g/kg_da], sloping enthalpy isolines h [kJ/kg_da]. The standard in European building services and HVAC design. It is the most widely used h-x chart online for engineers in Czechia.
• Carrier (ASHRAE) T-x chart — horizontal axis = temperature t [°C], vertical axis = humidity ratio x [g/kg_da]. Preferred in Anglo-Saxon practice; this is the psychrometric chart to use for air conditioning calculations in an English-speaking setting.

Both charts show identical psychrometric data — they differ only in the orientation of the axes and in their graphical appearance.

Reading the chart in detail, the meaning of the individual isolines and the typical tasks are covered in the guide The Mollier (h-x) chart.

Chart range

The range settings let you enter a minimum, a maximum and a step for both the temperature axis and the humidity ratio axis. The Reset to defaults button restores the standard range. For special calculations (dry air, extreme cooling, high-temperature processes), adjust the range as needed.

Atmospheric pressure

Set it in the Pressure field at the top of the left-hand panel — either directly in kPa (60–110 kPa), or switch to entering the altitude in metres and let the application compute the pressure per the ISA (International Standard Atmosphere). The pressure can also be taken from the selected climate location. Atmospheric pressure affects every curve in the chart as well as the results of all psychrometric calculations; changing it triggers an automatic recalculation of the whole project.

Working zones (Boundary conditions)

The Boundary conditions panel lets you define working zones — colour-marked areas in the chart (a range of t and φ), for example the required band for the indoor environment. Zones can be named, coloured and hidden individually.

Auxiliary lines (SHR, dh/dx)

Auxiliary lines with a given slope can be added to the chart: SHR (Sensible Heat Ratio) or dh/dx — drawn from a reference point of the chain. Useful for the graphical design of a cooling process or for checking the slope of a humidification process.

Chart legend

Click Legend above the chart to show/hide the legend of the sets. Legend settings:

• Point label — show the process type / the custom label / both
• Hide types — pick the process types you do not want to appear in the legend
• Nodes without result — hide processes with no result (error, empty set)
• Sets layout — stacked or side by side

Chart info panel

Shows the project name, designation, building and author inside the chart area. Useful for PDF exports attached to technical documentation.

Chart style and layout

The Graphics settings panel lets you customise the visual style:

• Colours, steps and line widths of the isolines (isotherms, isenthalps, relative humidity curves, saturation curve)
• Process arrow type (filled / open / tick / none), line widths, point size and font
• Font sizes of the axes and labels
• Aspect ratio of the chart — auto, A4 landscape, A4 portrait, or a custom ratio (useful for printed output)

Dark mode

The sun/moon toggle in the top bar. The preference is stored in the browser and persists between sessions.

Hover synchronisation

Hovering over a row of the summary table or over a process card highlights the corresponding point and arrow in the chart, and the other way round. It makes calculations with a larger number of processes easier to navigate.

Moving points in the chart

Point Move mode (the button above the chart) lets you adjust the calculation by dragging points directly in the chart — the application back-calculates the input parameters of the process (an inverse calculation specific to the process type).

• Physical constraints — dragging respects the physics of the process: heating/cooling moves along x = const, adiabatic humidification along the isenthalp (h = const), points on the saturation curve along that curve (φ = 100%).
• Freezing axes — a chosen quantity can be locked so that dragging leaves it unchanged; with all axes frozen, motion is blocked.
• Points that cannot be changed by dragging (no inlet air, or zero flow rate, for instance) are marked by the application with an explanation.

Point Move works in both the Mollier and the Carrier chart.

Results overview table

The table below the chart lays out the air states (inlet / outlet) of all processes in the active set.

Displayed columns

Extended columns

Add any further columns by clicking ⚙ Customize columns:

• Dew point t_d [°C], wet-bulb temperature t_wb [°C]
• Partial pressure of water vapour p_w [kPa] and saturation vapour pressure p_ws [kPa]
• Degree of saturation μ [–], specific volume v [m³/kg], air density ρ [kg/m³], specific heat capacity c_p [kJ/(kg·K)]

The table can be copied to the clipboard and pasted into a spreadsheet.

Exporting and printing the results

The export buttons are in the top bar or in the Export drop-down menu.

Available formats

Format availability depends on development stage.

PDF header

The PDF header contains:

• Project name, designation, author, date of generation
• Atmospheric pressure [kPa] and altitude [m a.s.l.]

Sharing a project

Sharing is available to signed-in users includes link sharing.

Creating a share link

1. Click the Share button (arrow icon) in the top bar.
2. The application generates a temporary link with an expiry date.
3. Copy the link with the Copy button.

Revoking a link

In the sharing drop-down panel, click Revoke link.

Only projects stored in the cloud can be shared. The link is valid until the date shown. The recipient can only view the project — the data cannot be edited.

Modules

The Modules section (the menu next to the chart) holds specialised tools that go beyond the basic h-x calculation. Currently available modules:

Builder — visual assembly of an AHU — CURRENTLY IN DEVELOPMENT

An alternative way of building a calculation: you assemble the process chain visually from blocks on a canvas — like an air handling unit schematic — and write the result into the project as a new set.

• Block palette: inputs, heat and moisture processes, mixing + a fan (heat gain from the pressure rise, Φ = Δp · V̇ / 3,600,000) and mechanical parts — filter (class, clean/dirty Δp), dampers, droplet separator, empty chamber, silencer, weather louver, activated carbon filter, UV-C section. Mechanical parts record their pressure drop for the fan design point.
• Two rows — supply and exhaust: the unit can be built in both directions; heat recovery links the two rows (a plate exchanger crosswise, a rotor inline).
• Mixing chamber (recirculation): connects the exhaust back into the supply — you enter the ratio either as a percentage of return air or directly as the recirculation flow rate; the application keeps an eye on the fresh-air and exhaust balance.
• Operating modes: one unit, several operating modes (summer / winter / night operation…). When writing to the project you choose which modes to write — each becomes a separate set.
• A live preview of the outlet air state behind every block; climate data ❄/☀ can be applied straight into the inlet of the active mode.

Availability of this feature is not guaranteed.

Autopilot — automatic process sequence design — CURRENTLY IN DEVELOPMENT

Enter the start point (outdoor air), the target zone for the supply air/space, the space loads and the permitted processes — Autopilot searches for AHU process sequences automatically that bring the air to its “target”. It ranks the results by configurable weights (simplicity, energy estimate, supply ΔT, sequence logic) and the best sequence can be imported into the chart as a new set in one click. The manual design procedure that Autopilot automates is described in the article Air conditioning design in the h-x chart. When no solution is found, it advises what to relax (processes, number of steps, coolant range…).

Availability of this feature is not guaranteed.

Energy flow (Sankey) — CURRENTLY IN DEVELOPMENT

The Sankey diagram visualises the heat and moisture flow balances across the individual processes of the active set — the band width represents the air flow rate, the side streams show heat exchange and condensate. Preset levels of detail (Clean / Standard / Detailed).

Availability of this feature is not guaranteed.

Heat stress (WBGT) — CURRENTLY IN DEVELOPMENT

Assessment of worker heat stress per ISO 7243 — see the following chapter.

Availability of this feature is not guaranteed.

Toolbox — quick calculators — CURRENTLY IN DEVELOPMENT

Further modules (room air conditioning, cleanrooms, data centres, dryers, energy calculations, ventilation sizing…) are marked “Coming soon”.

Availability of this feature is not guaranteed.

Comfort analysis

Thermal comfort – PMV/PPD (ASHRAE 55, EN 16798-1) — CURRENTLY IN DEVELOPMENT

The Thermal comfort overlay draws comfort zones directly in the chart and computes the thermal comfort indices. The PMV/PPD calculation method per ISO 7730 is covered in the article Thermal comfort and the PMV/PPD index.

• PMV / PPD (Predicted Mean Vote / Predicted Percentage of Dissatisfied) per ASHRAE 55 — inputs: air velocity [m/s], activity (met), clothing (clo), radiant temperature [°C]; the t and φ values can be synchronised from any point of the chain
• PMV ±0.5 comfort zone drawn in the chart, both the standard ASHRAE 55 zones and custom parameters
• Adaptive model (ASHRAE 55 §5.4 / EN 16798-1) with a band based on the outdoor temperature
• SET (Standard Effective Temperature), Heat Index isolines, ankle draft check

WBGT (Wet-Bulb Globe Temperature, ISO 7243) — CURRENTLY IN DEVELOPMENT

A module for assessing worker heat stress per ISO 7243 — indoors and outdoors (solar radiation, wind speed, globe temperature t_g). The result is compared with the limits for acclimatised/non-acclimatised workers according to the metabolic rate and returns a verdict of WITHIN LIMITS / CAUTION / EXCEEDED. The t and φ values can be taken from a point of the chain.

Availability of this feature is not guaranteed.

Account settings

Available after signing in, via the user icon → Account.

Process property display

The global default visibility of the extended air properties (dew point, t_wb, density, humidity ratio…) across all process cards. It can be overridden on an individual card at any time.

Default process colours

• All black — every arrow and point is black (suitable for printing)
• One colour — a single colour of your choice for all processes
• Coloured by type — each process type has an assigned colour (heating = orange, cooling = turquoise, humidification = green, heat recovery = purple…)

Source of the physical constants

A switch between the ASHRAE Handbook – Fundamentals 2021 and Czech technical literature — it changes the constants and the calculation correlations to the defaults of the selected source.

White-label branding

For companies and design offices: you can upload a company logo and set a company name. Both appear in the application header and in the header of every exported PDF — the output looks like a company document, with no mention of PsychroView. This is an individual feature that is not commonly available.

Data export (GDPR Art. 20)

Download of all your personal data and projects in JSON format — fulfilling the right to data portability.

Physical quantities – overview

An overview of the psychrometric quantities used in the application and their symbols. Familiarity with these concepts is a prerequisite for psychrometrics for engineers — if any of them are new to you, we recommend going through the interactive guide in the application. Definitions, formulas and the normative context of each concept can be found in the glossary.

Tips, keyboard shortcuts and troubleshooting

Keyboard shortcuts

Tips for working efficiently

Automatic recalculation — the application processes every value you enter after a short delay (debounce). There is no Save button to press — psychrometric calculations run continuously.

Calculation variants side by side — make a copy of a process set and change a single parameter (the type of heat recovery exchanger or the coolant temperature, for instance). Both variants appear in one Mollier h-x chart, so the comparison is immediate.

Climate data instead of typing values — fill the inlet point with the design conditions of a location (Czechia, DE, AT, city search anywhere in the world, your own EPW file or an import) — including the correct atmospheric pressure derived from the altitude.

Lock an approved calculation — once the results have been signed off, lock the set. That prevents accidental edits while presenting the calculation or handing it over to a colleague.

Start from an example — the example projects in the overview show typical arrangements (heat recovery, cooling with reheat, humidification…) and can be opened as the starting point of your own calculation.

Offline access — the core psychrometric application works without an internet connection too (the calculations run in the browser). Cloud storage, climate data and sharing require a connection.

Solving common problems

PsychroView — professional online psychrometrics for designers of building services, ventilation and air conditioning in Czechia and abroad.

Manual version: 3.0 (July 2026) · psychroview.com