Why Does Refrigerant Size Matter?

Why Does Refrigerant Charge Size Matter When Buying a Chiller?

When purchasing a chiller – whether for a laboratory, industrial test rig, or precision manufacturing environment – one technical specification you may come across is the refrigerant charge size.

This refers to the amount of refrigerant inside the unit. While it’s something that the manufacturer typically manages, it can affect where your chiller can be installed, how it’s delivered, and whether it will comply with environmental regulations – now and in future years.

Here’s what you need to know to make an informed, confident choice.

Regulatory Landscape: What’s Changing Under F-Gas and Kigali?

The amount and type of refrigerant used in chillers is now heavily influenced by environmental regulation.

UK & EU F-Gas Regulations

These rules are phasing down the use of high-GWP refrigerants such as R134a and R404A. Instead, manufacturers are moving to low-GWP alternatives like R290 and R454C.

F-Gas regulations limit the total volume of refrigerants (by CO₂-equivalent) allowed on the market. They encourage smaller charge systems using more climate-friendly refrigerants and are introducing bans on certain refrigerants and equipment types from 2025 onward.

The Kigali Amendment is a UN-backed global agreement that obliges signatory countries (including the UK) to phase down the use of HFCs, support alternatives with lower climate impact, and implement GWP-based restrictions.

What this means for you:

Buying a chiller that uses a low-charge of a low-GWP refrigerant helps to ensure that it will remain legal, serviceable, and supportable for years to come. It also reduces the risk of needing costly refrigerant swaps or retrofits later. For organisations with sustainability goals, choosing low-charge, low-GWP systems aligns with environmental sustainability goals and net-zero targets.

What to Ask & Why It Matters

Does this refrigerant comply with current and upcoming F-Gas regulations? – Ensures the unit will remain legal and supported in the UK/EU long-term.

Is this refrigerant being phased down or banned in any of the countries I operate in? – Prevents investing in equipment that may need replacement or modification in a few years.

Is this a low-GWP refrigerant? – Low-GWP options are more future-proof and often preferred for environmental sustainability goals.

What’s the charge size in terms of CO₂-equivalent (tCO₂e)? – Helps to assess environmental footprint and quota impact

Can this system be exported globally without refrigerant compliance issues? – Important for OEMs or global sites – Kigali rules vary by country

Environmental Impact: What Happens If There’s a Leak?

Even small leaks of high-GWP refrigerants can have significant environmental impact. For instance:

A leak of 1kg of R134a has the same climate impact as 1.4 tonnes of CO₂
A leak of 1kg of R290 has almost no long-term climate effect (GWP ~3)

Reducing charge size means:

Less refrigerant at risk of leaking
Lower carbon impact if something does go wrong
Easier compliance with environmental reporting or lab audit requirements

What to Ask & Why It Matters

What happens if this system develops a leak – what is the environmental impact? – Smaller charges and low-GWP refrigerants reduce long-term climate impact

Is this refrigerant subject to leak monitoring or reporting in regulated industries? – Ensures compliance with sustainability or audit requirements

Does using a low-charge system help with our net-zero or green procurement goals? – Supports purchasing policies focused on sustainability and reduced CO₂ footprint

Can I share refrigerant/environmental information with internal sustainability teams? – Allows integration into environmental sustainability goal reporting and environmental audits

Transport & Shipping: How Fast Can You Get It?

Refrigerant charge size plays a key role in determining how easily, affordably, and quickly your chiller can be shipped, especially if you need it delivered internationally or on a tight timeline. This applies to both air freight and sea freight, and to whether the unit is shipped pre-charged with refrigerant or requires on-site charging at its destination.

Air Freight: Fast, but Tightly Regulated

Flammable refrigerants like R290 and R454C fall under Class 2.1 (flammable gases) in the IATA Dangerous Goods Regulations (DGR).

According to the IATA DGR, R290 can be transported by air in quantities less than or equal to 100 grams, only if the gas is fully contained within equipment that has been tested to withstand pressure conditions, the equipment is hermetically sealed and designed to withstand internal pressures, and all packaging, documentation, and labelling meet IATA requirements. Even then, not all carriers accept Class 2.1 flammable gases, and many refuse to ship R290 altogether, regardless of charge size.

Any quantity of R454C is subject to full dangerous goods regulations under IATA DGR. There is no minimum quantity exemption, even small charges must be declared and labelled correctly, shipped in certified packaging, and documented with the proper paperwork. Some air carriers may still accept R454C, but with strict conditions.

Small chillers with very low charges may sometimes qualify for air freight under exemption rules (R290 <100g) – but this must be confirmed on a case-by-case basis. Most equipment using R290 or R454C will need dangerous goods handling, and may not be accepted by all air freight providers. If speed is critical, ask in advance whether your unit qualifies for air shipping and what documentation will be required.

Sea Freight: More Flexible, but Slower

Sea freight is generally more accommodating for larger charge sizes, and while flammable refrigerants are still regulated, the requirements are easier to meet than by air.

R290 and R454C are both covered by the International Maritime Dangerous Goods Code. All systems containing these refrigerants must be properly declared, packaged and labelled per UN guidelines, and accompanied by a Material Safety Data Sheet and other documentation.

Unlike air freight, there are no universal quantity-based exemptions for R290 or R454C in sea freight – the key difference is that most sea freight carriers will accept properly declared shipments.

What this means for you:

Larger chillers, or those using higher charges of R290 or R454C, are typically shipped by sea.
This can extend lead times by several weeks depending on destination – so planning is essential, especially if the chiller is needed urgently.

On-Site Charging: Commissioning at Destination

Because of transport restrictions, some chillers are shipped uncharged or partially charged and must be filled with refrigerant on-site.

This is especially common if:

The refrigerant charge exceeds 100g for R290, making air shipment impractical
You are shipping to a country where flammable refrigerants cannot legally be imported pre-charged
Local regulations require charging to be carried out by a licenced professional

If on-site charging is needed, you will need a qualified refrigeration technician, access to locally sourced refrigerant, and tools to evacuate, fill, and pressure-test the system.

We can advice during quoting whether on-site charging is likely, and support you with clear instructions or local service connections.

What to Ask & Why It Matters

Can this unit be shipped by air, and is it under the dangerous goods threshold? – Determines if fast, cost-effective shipping is an option

Does this model need to be shipped charged or can it be charged on-site? – Affects installation planning and technician availability

Will it ship with the correct documentation and packaging for sea/air freight? – Prevents delays, refusals, or compliance issues at ports and borders

Are there local refrigerant restrictions in the destination country? – Ensures that your unit can be legally and safely charged after delivery

If on-site charging is needed, can I source the refrigerant and qualified labour? – Avoids costly hold-ups and failed installations

Room Size & Safety: Where Can You Use the Chiller?

If your chiller uses a flammable refrigerant, such as R290 or R454C, there are international safety standards that limit how much refrigerant can be safely used based on the volume of the room where it will be installed.

This is to prevent any risk in the unlikely event of a leak. If a leak occurred in a small, poorly ventilated space, the gas could (in theory) build up to a flammable concentration.

To prevent this, standards like EN 378 (used across Europe and the UK) and IEC 60335-2-40 set out maximum charge limits that are tied to the room’s floor area and the refrigerant’s Lower Flammability Limit (LFL).

For example:

R290 has an LFL of 0.038kg/m³
R454C has an LFL of 0.111kg/m³
Based on EN 378, the maximum allowable charge of R290 in a 10m² room without forced ventilation is roughly 226 grams
For R454C in the same room, the limit is around 660 grams

These limits increase with room size and/or ventilation. In a 30m² space, the allowable charge of R290 rises to around 680 grams.

What to Ask & Why It Matters

Is this refrigerant suitable for the size of the room I’ll be installing the unit in? – To ensure compliance with safety standards like EN 378 and avoid installation restrictions

What’s the refrigerant charge of this unit, and does it stay under the threshold for my room size? – Higher charges may require ventilation or may not be allowed in smaller spaces

Can I install this unit without adding gas detection or extra ventilation? – Lower-charge systems reduce or eliminate the need for costly safety modifications

What happens if I need to move this unit to a different room in the future? – Ensures ongoing flexibility without triggering compliance issues

Making the Right Choice with Confidence

While refrigerant charge size might seem like a behind-the-scenes detail, it has a meaningful impact on the installation, delivery, environmental impact, and long-term compliance of your chiller. As global restrictions shift and low-GWP refrigerants become the new standard, it’s more important than ever to understand how charge size affects safety thresholds, shipping logistics, and sustainability goals.

The good news is that you don’t have to navigate it alone. By asking the right questions and working with an experienced supplier, you can be confident that your chiller is safe, compliant, and future-ready. Whether you’re sourcing equipment for a compact lab, an industrial test cell, or a global project with strict logistics, choosing a unit with the right refrigerant charge will help you to stay ahead of regulations and avoid unnecessary costs or complications later on.

At Applied Thermal Control, we’re here to guide you through the process – offering practical advice, straightforward answers, and products designed with global regulations and real-world applications in mind. If you’re unsure about what’s right for your application, our team is happy to help.

Get in touch today!