Question 1

What temperature do fruit preservation rooms need?

Accepted Answer

It depends on the product: apples and pears are stored between 0°C and 2°C, peaches and nectarines between -0.5°C and 1°C, citrus between 5°C and 10°C depending on the variety, and table grapes between -1°C and 0°C. Storage temperature must be held within ±0.5°C to avoid condensation and chilling injury. At Isofred we design the facility from the thermal load calculation to automatic setpoint regulation by variety and season.

Question 2

What is the difference between standard controlled atmosphere and ULO?

Accepted Answer

Standard controlled atmosphere (CA) works with O₂ levels between 1% and 3% and CO₂ between 1% and 5%, achieving 6 to 9 months of storage for apples. ULO (Ultra Low Oxygen) technology reduces O₂ below 1% and allows storage of up to 10 months. DCA (Dynamic Controlled Atmosphere) goes further: it adapts O₂ levels to each batch's real metabolism week by week, reaching 12 months with maximum organoleptic quality. Isofred installs all three systems according to each client's needs.

Question 3

What is hydrocooling for and which products use it?

Accepted Answer

Hydrocooling pre-cools fruit with iced water in minutes instead of hours, removing field heat right after harvest. It is especially effective for peach, nectarine, cherry, strawberries, asparagus and green beans, where pre-cooling speed directly determines shelf life. A peach at 30°C can reach 2°C in 15-20 minutes with hydrocooling versus 4-6 hours in a conventional room. Isofred designs and installs hydrocooling lines integrated into the fruit handling chain.

Question 4

Which refrigerant is best for large fruit and vegetable plants?

Accepted Answer

For plants above 500 kW, ammonia (NH₃/R717) is the preferred choice: 15-20% better coefficient of performance than HFCs, minimal refrigerant cost, zero GWP and a facility life of over 30 years. For medium facilities (100-500 kW), subcritical CO₂ in cascade with NH₃ or transcritical CO₂ are alternatives with excellent efficiency and no F-Gas restrictions. At Isofred we have been installing NH₃ plants for cooperatives and wholesalers across Spain for over 25 years.

Question 5

How is peach and nectarine ripening controlled post-harvest?

Accepted Answer

Ripening control for peach and nectarine requires managing temperature (between -0.5°C and 1°C), relative humidity (90-95% RH) and ethylene levels simultaneously. DCA systems adapt the atmosphere to each variety and phase of the commercial cycle. For citrus degreening or cold-shock treatment, Isofred designs rooms with zone-differentiated control that can manage different batches simultaneously with independent parameters.

Coldroomsforfruitandpost-harvest.

Technical solutions for post-harvest.

Preservation rooms

Hydrocooling and pre-cooling

Controlled atmosphere and DCA

High-capacity NH₃ plants

SCADA control and remote management

Need a custom project?

Success stories.

PAC Aitona - Stone Fruit Storage

Grupo Frutas David - Dynamic Hydrocooling

Piñana / Conjuntfruit - Controlled Atmosphere Storage

Preguntasfrecuentes.

What temperature do fruit preservation rooms need?

What is the difference between standard controlled atmosphere and ULO?

What is hydrocooling for and which products use it?

Which refrigerant is best for large fruit and vegetable plants?

How is peach and nectarine ripening controlled post-harvest?

Ingenieríafrigoríficaindustrialcon+25añosdetrayectoria.