By Qishanr Technical Team · Published 23 September 2026
Retrofit report · QISHANR SW 68 (POE 68) · Supermarket rack system converted from R22 to R404A
QISHANR SW 68 is an ISO VG 68 synthetic polyolester (POE) refrigeration compressor oil, blended for HFC systems. It is specified where an oil has to stay miscible with the refrigerant at low evaporating temperatures, which is the condition a supermarket rack creates.
| Item | Detail |
|---|---|
| Customer | A supermarket operator (not named) |
| Application | Supermarket rack system retrofitted from R22 to R404A, low-temperature evaporators |
| Product | Qishanr Ester Oil SW 68 (POE 68), ISO VG 68, 68 mm²/s at 40 °C |
| Oil family change | Mineral oil replaced by POE as part of the refrigerant retrofit |
| Specification matched | Emkarate RL 68H, the specification the site had been using |
| Top-up without a drain | One Carrier unit still holding Totaline SW-68 was topped up with SW 68; no compatibility issues |
| After three months | Reliable oil return, no oil logging, clear sight glass, stable discharge temperatures, quieter rack, no low-oil alarms |
| Supply and documents | On-time delivery, vacuum-sealed pails, MSDS, CO and COA complete |
| Next step | Stock ordered to cover the rest of the fleet |
The operator sent a review that covers the retrofit, the top-up case and three months of operation. Here it is in their words:
We recently retrofitted our supermarket rack system from R22 to R404A, which meant switching the compressor oil from mineral to POE. The sales engineer confirmed our compressor model and refrigerant first, then matched QISHANR SW 68 to the Emkarate RL 68H spec we had been using — direct replacement, no system flush required. We even topped up one Carrier unit that still had Totaline SW-68 in it without draining; no compatibility issues at all. Delivery was on time, and the pails arrived vacuum-sealed — important, because POE absorbs moisture. The documents (MSDS, CO, COA) came complete. After three months of operation, oil return through the low-temperature evaporators has been reliable — no oil logging, the sight glass stays clear — and discharge temperatures are stable. The rack runs noticeably quieter, and we haven't had a single low-oil alarm since the changeover. One small suggestion: a moisture-indicator label on the pail would be a nice addition for us technicians, given how hygroscopic POE is. We've already ordered enough to cover the rest of our fleet.
The refrigerant change drives the oil change. Mineral oil and R404A do not stay mixed: the oil separates out and collects where the refrigerant is coldest, which on a rack means the low-temperature evaporators.
That condition is what the trade calls oil logging, and a rack that logs oil loses heat transfer at the coil and lubricant at the compressor sump at the same time.
POE is the oil family that solves it. Polyol ester stays miscible with HFC refrigerants such as R404A and R507, so the oil travels with the refrigerant instead of settling out of it.
Miscibility is the ability of an oil and a refrigerant to form a single liquid phase rather than separating into layers.
The grade stays where it was. This site was running an ISO VG 68 specification, so the retrofit kept ISO VG 68 and changed the oil family from mineral to POE. That is why SW 68 was the match rather than a heavier or lighter grade.
An ISO viscosity grade describes an oil's kinematic viscosity at 40 °C. QISHANR SW 68 measures 68 mm²/s at that point, and kinematic viscosity in this class is measured under ASTM D445 at 40 °C and 100 °C.
The order of operations matters as much as the grade. Our published guidance is explicit that SW 68 is not to be introduced into an R22 circuit that still holds mineral oil. The refrigerant retrofit comes first, and the oil change follows it.
Oil return is the measurement a supermarket engineer actually watches, because a rack can hold temperature perfectly and still fail slowly from oil that never comes back.
Oil logging is the accumulation of oil inside an evaporator, where it displaces refrigerant and cuts heat transfer while starving the compressor of lubricant.
The symptoms arrive in a familiar order: a coil that stops holding temperature, a sump level that keeps falling, and eventually a low-oil alarm or a seized compressor.
The customer reported the opposite after three months. Oil return through the low-temperature evaporators stayed reliable, no logging appeared, and the sight glass stayed clear.
Cold flow supports that. SW 68 has a pour point below −30 °C, which keeps it mobile in the coldest part of the circuit; the standard pour point test is ASTM D97.
Stable discharge temperatures are the second half of the report. A flash point above 240 °C gives the oil thermal headroom on the discharge side, where a rack runs hottest and where a thinner, moisture-loaded oil would begin to break down.
Quieter running and no low-oil alarms are the consequences a maintenance team notices: oil in the sump, film on the bearings, and no alarm raised by a level that keeps dipping.
The specification match came before the price. The site had been running to an Emkarate RL 68H specification, and SW 68 is documented as a direct replacement for it, alongside Castrol Icematic SW 68 and Carrier Totaline SW-68.
That equivalence is what makes a mixed rack practical. One Carrier unit still held Totaline SW-68, and it was topped up with SW 68 without draining the charge.
Our guidance allows exactly that on one condition: the oil already in the circuit must also be POE of the same ISO VG 68 grade. SW 68 is not to be mixed into a mineral-oil R22 circuit.
Moisture is the discipline that comes with POE. These oils absorb water from the air, which is why every pack size ships sealed and why a container is resealed immediately after use.
Water content is a laboratory measurement rather than a visual one, and the standard method for it is ASTM D6304, the Karl Fischer determination of water in petroleum products.
The pails arrived vacuum-sealed and the document set was complete: MSDS, CO and COA. The customer asked for one addition — a moisture-indicator label on the pail for the technicians who open them in the field.
It is a practical request from people who handle hygroscopic oil every week, and it is recorded here as their suggestion. The rest of their fleet is already covered: the follow-on order is placed.
Published values for Ester Oil SW 68, with the test method shown where the specification names one.
| Parameter | Value | Method |
|---|---|---|
| Product / SKU | Ester Oil SW 68 (POE 68) / POE-SW68-5G | — |
| Oil type | Synthetic polyolester (POE) | — |
| Viscosity grade | ISO VG 68 (68 mm²/s at 40 °C) | ISO 3448 |
| Flash point | Above 240 °C | — |
| Pour point | Below −30 °C | — |
| Colour | Clear to pale yellow | — |
| Refrigerant compatibility | R134a, R410A, R404A, R507, R32, R744 (CO₂) | — |
| Compressor types | Scroll, reciprocating, rotary, screw | — |
| OEM equivalents | Castrol Icematic SW 68, Carrier Totaline SW-68, Emkarate RL 68H, Mobil EAL Arctic 68, Summit RPE-68 | — |
| Packaging | 1 L, 3.8 L (1 gal), 18.9 L (5 gal pail), 208 L (55 gal drum) | — |
The retrofit changed one variable only — the oil family — because mineral oil and R404A behave differently inside the same circuit.
Fig. 1 — Why the oil family had to change with the refrigerant on this retrofit, and what the customer reported after three months of operation.
A: SW 68 is documented as a direct replacement for Emkarate RL 68H, Carrier Totaline SW-68, Castrol Icematic SW 68, Mobil EAL Arctic 68 and Summit RPE-68, at the same ISO VG 68 grade. It can also be mixed with those oils during a top-up when the charge already in the system is POE of that grade.
A: No. SW 68 is a POE lubricant for HFC systems. On an R22 circuit the refrigerant has to be retrofitted first, and the oil change follows — which is the sequence this customer followed.
A: Because mineral oil separates out of R404A and collects in the coldest part of the circuit. POE stays miscible with the refrigerant, so the oil keeps moving through the evaporators and returns to the compressor instead of logging there.
A: Sealed, cool and dry, and resealed immediately after each use, because POE absorbs moisture from the air. Packs ship vacuum-sealed for the same reason, and water content is confirmed by laboratory test rather than by eye.
A: MSDS, certificate of origin and COA, alongside the commercial invoice. Packaging runs from 1 L and 3.8 L service sizes through the 18.9 L pail to the 208 L drum.
Retrofitting a rack from R22 to an HFC refrigerant? Send the compressor model, the new refrigerant and the grade on the nameplate — we confirm the oil family, the pack size and the documents before you order.
Request an SW 68 Quotation
