Why two similar-looking cabinets can perform completely differently

It's an easy assumption: bigger compressor, better cabinet. In practice, two cabinets with near-identical compressors can perform very differently once they're stocked and running on a real shop floor, and the difference usually comes down to airflow design rather than raw cooling capacity.

An open-front cabinet holds its temperature using an air curtain, a moving layer of cold air across the front opening that does the job a door would do on a closed unit. Get that curtain wrong, and warm ambient air infiltrates at the front. The compressor doesn't fail; it just works harder to compensate, cycling more often to hold the set temperature.

The symptoms are recognisable once you know what to look for: a warm top shelf even though the thermostat reads correctly, more frequent compressor cycling than the spec sheet would suggest, and condensation or frost building up faster than expected on the evaporator. None of that shows up by comparing kW ratings on a spec sheet.

When you're comparing quotes for open-front cabinets, it's worth asking what independent airflow or temperature-distribution testing the manufacturer can show, not just the compressor spec. That's usually the more honest predictor of how a cabinet will actually perform once it's stocked and trading.