Air Requirements of Ripening

Banana ripening airflow, and cooling requirements, are a little-understood “art”.

But there is a science to it…we will try to explain.

Most fruit have a specific heat of 9/10th’s of a BTU per pound. We use 1 BTU/pound as the cooling requirement (sometimes, like with avocados, for the heating too,) to be safe.

So, if you want to be able to cool your fruit by 1-degree (F) per hour, and you have 40,000 pounds of it, you need 40,000 BTU’s/hr of cooling capacity, plus extra loads for fan motors and other heat contributions, so we use a factor of 2-times, and say that we need 80,000 BTUs/hr for the task.

Airflow at static pressure is a little more tricky. It is almost impossible to predict how a commodity and packaging and palletization will react to airflow pressures, but there are some guidelines we can suggest.

For pressurized ripening, there are both tarp and tarpless systems. As a general rule of thumb, tarp systems need less airflow at higher static pressure (because the tops of the pallets are sealed off), and tarpless designs need more airflow at lower static pressure (because more air leaks out the tops of the pallets).

For tarp systems, we like 1,000 cfm per pallet, at 0.6″ water column static pressure.

For tarpless designs, we like 1,500 cfm per pallet, at 0.4″ static pressure.

In most cases, larger diameter fans can produce more cfm at higher static pressure, than can smaller diameter fans.

Do you have a ripening room or precooling need?  Please contact us for a free consultation and proposal., or

About Banana Jim

Invented Tarpless Ripening in 1990 (some would argue that!), working at D Theoderedis in Bethlehem, PA. Founded Thermal Technologies, then sold it in 1997. Now head up Global Cooling, with the best ripening rooms and precoolers available. Ethylene scrubbers and ultrasonic humidifiers, too.
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3 Responses to Air Requirements of Ripening

  1. Hi Jim

    Plaese help how can i get good air flow on a double stack ( 2 Tier ) system air flow will differ on bottom.

  2. Mark says:

    Do you leave the ethylene gas in the room for tomatoes until they ripen to the color you want or do you gas ripen them for 24 – 48 hours similar to what you would ripen bannanas.

    • Banana Jim says:

      Continuous gassing with ethylene, as opposed to for only a 24 to 36 hour period, will not ripen the pulp of the fruit any faster. It can, however, help with chlorophyll degradation / de-greening, in fruit of lesser maturity.

      B Jim

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