Why R744 is the natural-refrigerant answer for Singapore cold rooms. This explainer sets out the mechanism in plain terms so a facilities manager, contractor or specifier can act on it with confidence. Highlight any passage and ask MullerEDGE to go deeper: the assistant answers from this page and cites the source.
The regulation targets the refrigerant global warming potential, not the equipment class, so the practical test is the charge you specify at commissioning. From 1 July 2027, new centralised commercial refrigeration must use a refrigerant with a GWP no higher than 150.
For most Singapore retail and cold-store applications, a transcritical CO2 (R744) system is the natural-refrigerant route to compliance. The assistant can size a room and recommend a Muller unit from your duty.
Estimated cooling load
This is the required cooling capacity for the 5 x 5 x 3 m chilled storage room.
| Component | Heat Load (kW) | Share |
|---|---|---|
| Transmission (walls, ceiling, floor) | 2.13 | 24% |
| Air change | 4.19 | 48% |
| Product | 0.47 | 5% |
| Internal (lighting, people, motors) | 1.28 | 14% |
| Safety margin (10%) | 0.81 | 9% |
| Total | 8.88 | 100% |
Air change is the largest component at 48% of the total load, driven by the high ambient humidity assumed for Singapore. Transmission through the walls, ceiling and floor is the next largest at 24%.
| Parameter | Value |
|---|---|
| Room dimensions | 5 x 5 x 3 m |
| Room usage | Chilled storage |
| Room temperature | 2 °C |
| Parameter | Assumed value |
|---|---|
| Outside temperature | 38 °C |
| Relative humidity | 90% |
| Insulation | 100 mm PU/PIR panel |
| Operating hours | 16 h |
Recommended unit
Meets your 8.88 kW duty on R404A at your room condition. A candidate coil for your engineer to confirm, not a specified system.
| Your duty | 8.88 kW |
| Capacity at your condition | 9.65 kW |
| Spare margin | 9% |
| Result | Meets |
| Model | Muller MMT093 unit cooler |
| Refrigerant | R404A |
| Fin spacing | 6 FPI |
| Defrost | Electric |
| Fans | 2 × 350 mm |
| Air flow | 4,950 m³/h |
| Weight | 30.4 kg |
| Dimensions (L × H × D) | 1,485 × 470 × 545 mm |
MMT093 is the closest catalogue coil above your 8.88 kW duty at this condition, leaving about 9% in hand. The match is on capacity at your room temperature; air throw and coverage are read from the datasheet, not yet modelled by the tool.
This names the indoor coil only. Air coverage, mounting position and the matching outdoor condensing unit are for your engineer to confirm.
A transcritical CO2 booster system runs the whole store on R744, with two suction groups feeding one gas cooler.
In Singapore's ambient, parallel compression and flash-gas management recover most of the efficiency lost at high gas-cooler temperatures.
Muller MMT unit coolers are dual-discharge ceiling models for medium- and low-temperature cold rooms.
Confirm the exact model against the datasheet once you have the room duty. The heat-load calculator can size that for you.