R448A vs R449A: Which R404A Replacement Should You Use?

R448A and R449A are both low-GWP HFO/HFC replacements for R404A, with almost identical GWP (~1,390) and performance. The practical choice usually comes down to compressor manufacturer approval and availability rather than a clear technical winner. This guide compares them for UK engineers.

R448A vs R449A at a glance

Property	R448A (Solstice N40)	R449A (Opteon XP40)
GWP	~1,387	~1,397
Components	5 (incl. R1234yf + R1234ze)	4 (incl. R1234yf)
Glide	Moderate (~5K)	Moderate (~5K)
Safety class	A1	A1
Applications	LT and MT commercial	LT and MT commercial

The key differences

The main compositional difference is that R448A includes a small amount of R1234ze in addition to R1234yf, while R449A uses R1234yf only. This gives marginally different glide and capacity, but in real-world commercial refrigeration the performance is very close. Both cut GWP by around 65% versus R404A and improve efficiency in many medium-temperature applications.

How to choose

• Compressor approval: check which blend your compressor manufacturer approves – this is usually the deciding factor.
• Existing site standardisation: match what is already used across a multi-site estate.
• Availability and price: both are widely stocked; choose what your supplier has.

For the wider set of R404A options, see our R404A replacements comparison, plus the individual R448A and R449A guides.

Shared handling notes

• Both require POE oil when retrofitting from R404A.
• Both have moderate glide – charge as liquid, recover/recharge fully after a leak.
• Replace the filter-drier and recheck superheat after conversion.

Buying refrigerant in the UK

Refrigerant Gas Supplies Ltd supplies F-Gas compliant refrigerant to certified UK engineers, including R404A – browse the full refrigerant gas range. F-Gas certification is required to purchase.

Frequently asked questions

Is R448A or R449A better?

They are very close in GWP and performance. Neither is clearly better; the choice usually depends on compressor manufacturer approval, site standardisation and availability.

What is the difference between R448A and R449A?

R448A is a five-component blend that includes R1234ze as well as R1234yf, while R449A is a four-component blend using R1234yf only. This gives marginally different glide and capacity.

Do R448A and R449A need a POE oil change?

Yes. Both typically require a change to POE oil when retrofitting from R404A, plus a new filter-drier and component checks.

Can I mix R448A and R449A?

No. Never mix refrigerants. Recover the existing charge fully and recharge with a single refrigerant.