Enter the refrigerant type and charge for each system and the calculator produces CO2e, the required leak check frequency, whether automatic leak detection is needed, and what records you must keep.
What it calculates
- CO2e in tonnes, from refrigerant type and charge in kilograms.
- Whether mandatory periodic leak checking applies, against the current thresholds.
- The required interval, and how it changes if automatic leak detection is fitted.
- Whether automatic leak detection is mandatory for that system.
- What records are required.
- A site summary where multiple systems are entered, with next due dates.
CO2e = charge in kg x GWP / 1000. Both input figures are on the outdoor unit nameplate, and the GWP for each refrigerant is a published fixed value.
Why the arithmetic matters
Almost every threshold in the F-Gas regime is expressed in tonnes of CO2e rather than in kilograms of refrigerant. Because refrigerant GWPs vary by a large factor, two systems with the same physical charge can have completely different obligations.
| Consequence | Why |
|---|---|
| Thresholds apply per system, not per site | Ten small splits below the threshold have no mandatory checking; one large system with the same total charge may need frequent checks |
| Refrigerant type matters as much as quantity | A high-GWP refrigerant reaches a threshold at a far smaller physical charge |
| Replacing plant can remove an obligation | Modern low-GWP equipment may fall below a threshold entirely – a real ongoing saving that belongs in the business case |
| Additional charge counts | Refrigerant added for long pipe runs at commissioning is part of the total |
| Hermetically sealed equipment has a higher threshold | Reflecting the lower leak risk, where it is labelled as such |
The nameplate usually shows the factory charge. Where pipe runs exceeded the pre-charged length, more refrigerant was added at commissioning and it counts. If nobody recorded it, that is a gap worth closing – you cannot demonstrate compliance without an accurate total.
What you need to enter
- Refrigerant type – R410A, R32, R134a, R407C and so on, from the nameplate.
- Charge in kilograms, from the nameplate. Check the units – some are given in grams.
- Any additional charge added at commissioning, from the records.
- Whether the equipment is hermetically sealed and labelled as such.
- Whether automatic leak detection is fitted.
- The date of the last leak check, to produce a next-due date.
Repeat for each system. A typical commercial site has more systems than people expect – cellar cooling, display refrigeration and comms room units being the classic omissions.
What it will not do
It will not replace the records. The calculation is the starting point; you still need a logbook per system with the actual check history, and you still need to hold your own copy rather than relying on a contractor’s – see what an F-Gas logbook must contain.
It will not carry out the checks, which must be done by a certified person working for a certified company.
And it will not be a substitute for checking the current regulation. Thresholds and intervals are set in law, they have changed, and the calculator will be maintained against current guidance – but for anything consequential, confirm against gov.uk.
The architecture for it is defined and it is not yet live. In the meantime we will carry out the asset survey and the calculations as part of a site visit, and you get the register and the schedule regardless of what happens next.
If you have never done this
- Walk the whole siteIncluding roof, plant rooms, cellars and comms rooms. Include refrigeration as well as air conditioning.
- Photograph every nameplateRefrigerant type and charge, plus make, model and serial.
- Calculate CO2e per systemCharge times GWP.
- Establish the resulting obligationsInterval, and whether leak detection is required.
- Create a logbook per systemAnd a one-page site summary with next due dates.
- Verify your contractor’s certificationIndividual qualifications and company certification. Both are required.
- Start the scheduleYou cannot recreate past checks. A site compliant going forward is in a fundamentally different position from one that is not.
See F-Gas for facilities managers for the ongoing routine, which is about five minutes a month once the setup is done.
Not sure what you have? One survey produces the register, the calculations and the schedule – and it is yours whatever you do next.
Questions we get asked about this
How do I calculate CO2e?
Refrigerant charge in kilograms multiplied by that refrigerant’s GWP, divided by 1000 for tonnes. Both charge and type are on the outdoor unit nameplate.
Does the threshold apply per system or per site?
Per system. Several small systems each below the threshold have no mandatory checking; one large system with the same total charge may have frequent checking.
What if I do not know the charge?
It is on the nameplate. If the nameplate is missing or illegible, the equipment documentation or the manufacturer can provide it. Without it you cannot demonstrate compliance.
Does replacing equipment reduce my obligations?
It can, significantly. A lower-GWP replacement may fall below a threshold, removing the mandatory leak checking obligation for the life of the new plant. It belongs in the business case.
Does the calculator replace keeping records?
No. It tells you what your obligations are; you still need a logbook per system with the actual check history, held by you as operator.
Is the tool available now?
Not yet. We carry out the asset survey and the calculations as part of a site visit in the meantime, and the register is yours regardless.
Sources
- gov.uk guidance on fluorinated gases (F gases) — https://www.gov.uk/guidance/fluorinated-gases-f-gases
Regulations and standards referenced on this page
- Regulation (EU) No 517/2014 on fluorinated greenhouse gases, as retained and amended in GB law — UK Statute Law Database
- Fluorinated gases (F gases): guidance for operators and engineers — Environment Agency / Defra
Need this doing?
Call and describe the problem — you will speak to an engineer, not a call centre. Written quotes, no estimates over the phone.