How to Choose the Right Cold Room Monoblock Unit for Restaurant or Supermarket Walk-in Cooler

Monoblock refrigeration units are the preferred plug-and-play solution for restaurant and supermarket walk-in coolers and freezers. However, selecting an improper model leads to insufficient cooling, high energy consumption, frequent faults or wasted investment. This guide breaks down all key factors to help buyers pick the most suitable monoblock unit step by step.

1. Confirm Your Required Storage Temperature

Temperature is the first selection benchmark, which directly determines medium-temperature or low-temperature unit:

Medium Temperature (0°C ~ +5°C) – Walk-in Cooler

For fresh vegetables, fruits, dairy, beverages, cooked food, raw meat short-term preservation.

Low Temperature (-18°C) – Walk-in Freezer

For frozen meat, seafood, ice cream, frozen prepared food for long-term storage.

Important: Never use a medium-temp unit for freezing storage. It cannot reach -18°C and will cause continuous overload and compressor burnout.

2. Calculate Cold Room Volume & Match Unit Capacity

Estimate required cooling capacity based on internal cold room volume. Take into account frequent door opening in restaurants and supermarkets.

10–80 m³: Small capacity monoblock (3HP–5HP)

Suitable for small restaurants, cafes, convenience stores

80–250 m³: Medium capacity monoblock (8HP–15HP)

Suitable for mid-size restaurants, supermarket back storage, seafood shops

250 m³ and above: High capacity / Industrial monoblock (20HP–30HP)

Suitable for large central kitchens, supermarket distribution cold rooms

Additional allowance:

If the cold room door opens frequently, add 20%–30% extra cooling capacity to avoid temperature instability.

3. Select Installation Style: Through-the-Wall or Rooftop

Through-the-Wall Monoblock

✅ Pros: Easy ground-level maintenance; no roof reinforcement needed; lower installation cost

❌ Cons: Occupies wall position inside the cold room and reduces storage space

Best for: Small & medium restaurants, renovation projects of existing cold rooms

Rooftop Monoblock

✅ Pros: No occupation of internal storage area; better heat dissipation; quieter inside the cold room

❌ Cons: Requires roof opening and roof load check; service needs roof access

Best for: Supermarkets, large kitchens, businesses aiming to maximize storage space

4. Choose Defrost Type: Electric Defrost vs Hot Gas Defrost

Electric Defrost

Lower equipment cost, simple structure

Suitable for cold rooms with low access frequency, small capacity units

Hot Gas Defrost

Lower energy consumption, smaller temperature fluctuation inside cold room

Preferred for supermarkets and busy restaurants with frequent door opening, medium & large freezer rooms

5. Refrigerant Selection

R404A: Standard refrigerant for -18°C low-temperature freezer, stable performance, widely supplied (most common choice)

R507: Alternative to R404A with better cooling efficiency

R290: Low-GWP eco-friendly refrigerant, for regions with strict environmental regulations

6. Power Supply Confirmation

3HP / 5HP small units: 220V 1-phase or 380V 3-phase optional

8HP and above medium & large units: Mostly 380V 3-phase industrial power

Confirm on-site power condition before ordering to avoid rework.

7. Check Essential Protection & Configuration

Qualified commercial monoblock must include:

Microcomputer intelligent temperature controller

High/low pressure protection, compressor overload protection, phase loss protection

IP54 waterproof & dustproof cabinet

Automatic timed defrost function

8. Budget & Working Condition Considerations

For short-term use or small shops: Standard domestic monoblock balances cost and performance

For 24-hour continuous operation (supermarket, central kitchen): Choose reliable brand compressors (scroll / semi-hermetic) to reduce breakdown losses

High ambient temperature areas (above 35°C): Request enhanced condenser to guarantee cooling effect in summer

Quick Selection Checklist Summary

Define target temperature: Cooler (0~5°C) or Freezer (-18°C)

Measure internal cold room volume → match HP size

Decide: Through-the-wall or Rooftop mounting

Pick defrost mode: Electric or hot gas defrost

Confirm refrigerant and available power supply

Evaluate daily access frequency to decide whether to add extra cooling margin