A name for your own use, for example "Cold room 2, shop X". Shown in the printout. Does not affect the calculation.
The country where the unit stands. It decides which bans and service bans are shown and which safety standard the app refers to. Preset from the browser's language and country.
Only if the unit is covered by an exemption from the service bans. Leave "No exemption" for ordinary units. The exemptions do not apply to the leak checks.
The refrigerant in the unit today. It is on the nameplate and on the unit's refrigerant label.
What the unit is used for. The choice fills in typical temperatures and decides which service bans apply (refrigeration or AC/heat pump).
The evaporating temperature in design operation: the saturation temperature at the suction pressure (read on the gauges or the controller). For gliding blends: the dew point (or the mean temperature, see Advanced).
The condensing temperature in design operation (the hottest day): the saturation temperature at the condensing pressure. Typically 10–15 K above the ambient air for an air-cooled condenser.
Type of compressor. The reciprocating compressor has a clearance volume that lowers the capacity at a high pressure ratio; this is included. Scroll and screw are worked out without.
The oil in the compressor today (nameplate or service log). Decides whether the oil has to be changed.
Type of expansion valve. Decides how the valve must be adapted after the change.
Maximum allowable pressure (PS) as gauge pressure, for the high and the low side. It is on the nameplate or in the declaration of conformity (PED). The new refrigerant's saturation pressure at the design temperature (EN 378-2) may not exceed PS. The default is a typical value for the current refrigerant – replace it with the real one.
The unit's cooling capacity today (optional). Then the new capacity is shown in kW and the mass flow in kg/h. Empty = comparison in percent.
The refrigerant charge of the unit (optional). It is on the nameplate or in the log. Then CO₂e, the leak check interval and an estimate of the new charge are shown.
Superheat at the evaporator outlet that the valve is set to today (typically 5–8 K for AC, 6–10 K for refrigeration). Also used to work out how the valve must be adjusted.
Subcooling of the liquid before the expansion valve (typically 2–5 K).
How the temperatures are given for blends with glide. The dew point is used in EN 12900 and by most European compressor makers. The mean temperature (between dew and bubble point) is sometimes used in North America and by some refrigerant makers – the blends' capacity then looks higher.
Highest ambient temperature where the unit stands. Gives the temperatures for the minimum PS to EN 378-2: ≤ 32 °C → 55 °C high side / 32 °C low side; ≤ 38 °C → 59/38 °C; ≤ 43 °C → 63/43 °C (air-cooled condenser).
Highest allowable discharge temperature as the compressor maker gives it (often 120–140 °C on the discharge pipe). The app warns when the calculated discharge temperature is above it. Note: the calculation leaves out motor heat, the real discharge temperature is somewhat higher.
How many kelvin the superheat changes per turn of the adjusting spindle on your valve. It is in the valve maker's data sheet or installation instructions and differs between makes and sizes. With the value entered, the app works out roughly how many turns to make. Empty = change in kelvin only.
Optional. The highest pressure ratio (condensing pressure divided by evaporating pressure, absolute) the compressor's application envelope allows, from the maker's diagram or data sheet. The app warns when a refrigerant gives a higher ratio at your temperatures – R32 and R454B, for example, give a higher ratio than R410A.
Choose the refrigerant the compressor data and the price below belong to – the current one or an alternative. ★ marks refrigerants with data entered. Without data the app uses the simple cycle (isentropic efficiency 0.70).
Optional. The ten EN 12900 coefficients from the compressor maker's software or data sheet (e.g. Bitzer Software, Copeland Select), for capacity and power in W with t₀ and tc as dew point in °C: X = c1 + c2·t₀ + c3·tc + c4·t₀² + c5·t₀·tc + c6·tc² + c7·t₀³ + c8·tc·t₀² + c9·t₀·tc² + c10·tc³. Enter them for the current refrigerant AND for the alternative – only then are capacity, COP and mass flow taken from the compressor data.
The suction superheat the maker's coefficients are rated at. EN 12900 usually: 10 K superheat, 0 K subcooling. The app moves the values to your superheat and subcooling (mass flow by suction gas density, capacity by the enthalpy difference).
Optional. Price of the refrigerant chosen above per kg (or per lb), in your currency, including any tax per kg (e.g. Danish HFC levy). Enter it for the current refrigerant and the alternatives you compare; the details then show the cost of the charge.
Optional. The currency sign shown with the costs, e.g. SEK, EUR, NOK, DKK, USD.
Optional. A tax or levy per tonne CO₂e (e.g. Norway's tax on HFCs), added to the price: charge × GWP / 1000 × tax. Leave empty if the tax is already in the price per kg. The app holds no tax rates – enter the current one yourself.
The file is a link file: double-click it to open the project in your browser, or choose it with Open. Older .json files can still be opened. Like the project file, it contains all project data – share it only with people who may see it.
Fill in on site or on paper after printing. The fields follow the records of (EU) 2024/573 art. 7: quantity and type of refrigerant added and recovered, whether reclaimed or recycled, the company and technician with certificate numbers, and the leak check. Keep the record for at least 5 years.
Conversion R404A → R507A
| Temp. °C | Pressure |
|---|---|
| -22 | 1.90 |
| -18 | 2.37 |
| -14 | 2.90 |
| -10 | 3.48 |
| -6 | 4.13 |
| -2 | 4.84 |
| 2 | 5.63 |
| Temp. °C | Pressure |
|---|---|
| 28 | 12.84 |
| 32 | 14.33 |
| 36 | 15.94 |
| 40 | 17.67 |
| 44 | 19.53 |
| 48 | 21.53 |
| 52 | 23.67 |
Gauge pressure in bar(g), around your evaporating and condensing temperature (bold = your operating point). Superheat = line temperature at the suction minus the dew temperature at the suction pressure; subcooling = bubble temperature at the liquid pressure minus the line temperature. For a blend with glide read the dew column on the suction side and the bubble column on the liquid side.
The suitability (0–100 points) shows how closely the new refrigerant keeps the unit at what it was built for. Each part gives full points at the same value as today and zero at the deviation given:
An alternative with a red warning (PS exceeded, service ban, ozone-depleting, A3, CO2) gets at most 25 points and the category Not suitable.
Category: Drop-in = same oil and class, capacity within ±10 %, the valve fits and the superheat changes by at most 2 K. Near drop-in = same oil and class, but the valve or the capacity must be adapted. Retrofit = oil change and/or A2L. Not suitable = red warning.
The units you add are saved in the project file. Open one to work on it, or print the summary with the best alternative for each unit.
R404A (GWP 3922) can no longer be serviced with new gas in the EU. These are the usual drop-in or near drop-in replacements for medium and low temperature refrigeration. Capacity and COP below are relative to R404A for a typical reciprocating unit; run your own unit to get exact figures.
Under (EU) 2024/573, blends with GWP 750 or more are not allowed as new gas in stationary refrigeration from 2032 (reclaimed or recycled gas stays allowed). Servicing R404A with new gas has been banned since 2025; reclaimed gas is allowed until 2029.
Most common are R448A and R449A (GWP about 1400), R407F, R407A and R452A. They are A1 and run on POE oil like R404A, but usually need the expansion valve adjusted. R452A is closest to R404A in pressure and discharge temperature. A2L options such as R454C and R455A have GWP below 150 but need a new risk assessment.
Drop-in means the refrigerant can be changed with no other change than adjusting the superheat. Near drop-in needs an adaptation, for example a new orifice in the expansion valve or a changed controller setting. Retrofit needs an oil change (for example from mineral oil to POE) or a new safety class. Not suitable means that pressure, rules or flammability make the change impossible.
Almost always. A thermostatic valve has a charge made for the old refrigerant's pressure-temperature curve. With R448A instead of R404A the superheat drops by about 4 K if nothing is done, which can cause liquid slugging in the compressor. The app works out the change; turn the spindle clockwise for more superheat and always measure afterwards.
Work it out in the tool aboveCapillary tube sizing →
R134a is usually replaced by R513A (A1, GWP 629) or R450A, which have similar pressures and run on POE oil. R1234yf and R1234ze(E) have almost zero GWP but are A2L. R22 is replaced by R407C, R407A, R449A or R448A (oil change to POE), or by R417A and R427A with simpler oil handling. R422D has a GWP above 2500 and may no longer be charged into refrigeration units in the EU.
Work it out in the tool aboveGWP, ODP & CO2e of a refrigerant charge →
Every refrigerant is run through the same simple cycle with the same compressor: superheated suction gas, isentropic compression with 70 % efficiency, condensing and subcooling. The properties come from CoolProp. The capacity is the volumetric cooling capacity, corrected for re-expansion in a reciprocating compressor. It is a theoretical comparison, not the compressor maker's data.
Under (EU) 2024/573, refrigerants with a GWP of 2500 or more may no longer be used to service refrigeration equipment since 2025, nor air conditioning and heat pumps from 2026; reclaimed or recycled refrigerant may be used for a few more years. From 2032 the ban covers GWP 750 or more in stationary refrigeration equipment except chillers; reclaimed or recycled refrigerant stays allowed there, with no end date. The app marks these in the list.
GWP, ODP & CO2e of a refrigerant charge →Work it out in the tool above
