Topic: trading product technology (refrigeration units / cold rooms) | Date: 2026-07-31
For: Yuanxian team technical study, supporting the trading department on cold room unit enquiries
1. What Is a Cold Room Unit?
A cold room unit (condensing unit + unit cooler) is the heart of the food cold chain. A pre-cooler solves fast cooling before storage; a cold room solves long-term storage. Once a customer has asked about vacuum pre-coolers they will very likely ask about cold room packages next — that is the natural entry point for our trading products.
The knowledge base already holds complete supplier data: 18 models in the LZ series with 562 specifications (knowledge_base/cold-storage.yaml), split into three product lines:
| Series | Name | Models | Core selling points |
|---|---|---|---|
| LZAC | Air-cooled fixed speed | 7 | Scroll compressor + single/dual EEV, R410A/R404A, -35 to +20°C |
| LZVAC | Air-cooled inverter | 3 | DC inverter + PID, cooling/heating/constant temperature modes, ±0.5°C |
| LZWC | Water-cooled | 8 | Shell and tube condenser, 62–69 dB(A) low noise, indoor installation with no outdoor space needed |
2. Reading the Capacity Table: Cooling Capacity Is a Curve, Not a Number
The trap most colleagues fall into when they first meet cold room units is assuming the nameplate carries a single cooling capacity. In fact each unit has a capacity table with nine evaporating temperature points, and selection must be checked back from the room temperature.
Take LZAC-12 (R410A, single EEV):
| Evaporating temperature | +20°C | 0°C | -10°C | -20°C |
|---|---|---|---|---|
| Cooling capacity (W) | 17,530 | 8,550 | 7,550 | 4,800 |
The pattern is obvious: the lower the room temperature, the faster the cooling capacity falls. A unit that delivers 8.5 kW in a 0°C fresh-keeping room has only 4.8 kW left in a -20°C freezer — a 45% difference. When a customer says “I want a 10 hp unit”, always ask about room temperature and volume, otherwise the selection is bound to be off.
Now look at LZAC-20 (R404A, dual EEV): 13,500 W at 0°C and 7,000 W at -20°C. Input power is 4.9 kW, giving a COP of about 2.75 at the 0°C duty — a number you can put straight into an electricity bill conversation with a customer.
How should single EEV and dual EEV be understood? A dual electronic expansion valve suits dual temperature zones and large temperature differences, with steadier cooling capacity in the low-temperature range (compare the LZAC-20 with dual valves at 7,000 W at -20°C against a single-valve unit at the same rating, which decays further), but it costs more. A single valve is enough for an ambient fresh-keeping room; a freezer room is better with dual valves.
3. Air-Cooled vs Water-Cooled vs Inverter: What to Recommend
| Dimension | LZAC air-cooled fixed speed | LZWC water-cooled | LZVAC air-cooled inverter |
|---|---|---|---|
| Installation | Outdoors, needs ventilation | Indoors, no outdoor space needed | Outdoors |
| Noise | 68–72 dB(A) | 62–69 dB(A), lowest | Low |
| Operating environment | -35 to +48°C | Needs cooling water / cooling tower | Wide range -35 to +48°C |
| Temperature accuracy | Standard | Standard | ±0.5°C |
| Electricity cost | Baseline | Slightly lower (low condensing temperature) | 30%+ saved in long-term operation |
| Recommended application | Small and medium cold rooms, Southeast Asia/Africa without water sources | Constrained plant rooms, urban supermarkets | Pharmaceutical cold rooms, multi-temperature zones, high electricity price regions |
Recommendations:
- Customer asks “which is cheapest” → air-cooled fixed speed (LZAC), simplest to install
- Customer asks “which saves power” → inverter (LZVAC), pays back in long-term operation, mandatory for pharmaceutical and precision temperature control
- Customer asks “can it be installed indoors” → water-cooled (LZWC), but it needs a cooling tower or water source, so remember water charges and the footprint of the tower
4. Standards and Certification: What Exports Must Pass (Key Section)
Among the compliance questions export customers care about most, there is a key new regulation to remember from 2025:
GB 44015-2024, Minimum Allowable Values of Energy Efficiency and Energy Efficiency Grades for Cold Stores (Rooms) and Compressor Condensing Units
- Published 2024-04-29, effective 2025-02-01 (already in force)
- Scope: prefabricated cold stores (rooms), civil-built cold stores, motor-driven positive displacement compressor condensing units
- Explicitly excluded: evaporative condensing units, site-assembled units, transport refrigeration boxes
- Significance: units sold in China must carry an energy efficiency grade label, with grade 1 the best. Low-efficiency units will be pushed out of the market
Quick Reference for Export Certification Standards
| Standard | Content | Meaning for trade |
|---|---|---|
| GB/T 21363-2018 | Positive displacement refrigerant compressor condensing units | Domestic acceptance basis |
| GB/T 10079-2018 | Single-stage reciprocating refrigerant compressors (units) | Compressor component standard |
| GB 50072 | Code for design of cold stores | Engineering design basis |
| GB/T 30134 | Code for cold store management | Operation and maintenance management |
| GB/T 21145 | Transport refrigeration units | Refrigerated vehicle packages |
| JB/T 7244 | Refrigerated cabinets | Supermarket terminal equipment |
| CE / CSA | EU / North American safety certification | Essential for exports to Europe and North America; ask about the target market before quoting |
Reminder: the LZ series documentation holds complete parameter tables (nine-point capacity tables, dimensions and weights, connection sizes). Every external quotation must carry the energy efficiency grade and the applicable room temperature range rather than just a horsepower figure — customer expertise varies, and the parameter table itself is a sales tool.
Knowledge tags
- Technical field: refrigeration systems / cold room engineering / energy efficiency standards
- Equipment and process: condensing units, scroll compressors, EEV, air-cooled/water-cooled/inverter
- Industries: food cold chain, supermarket retail, pharmaceutical cold chain, export trade
- Keywords: LZAC, LZVAC, LZWC, GB 44015-2024, condensing unit selection