A copy/paste-ready reefer controller and PTI settings sheet for Indonesian frozen seafood exports. Use these field-tested set points, vent, defrost, airflow, and pre-load steps to keep cargo hard-frozen without burn.
If you ship frozen seafood, you don’t need more theory. You need a settings line you can send to your forwarder so the box pulls down, stays dry, and arrives hard-frozen without alarms. That’s what we use at Indonesia-Seafood for shipments of shrimp, snapper, grouper, tuna and more. We’ve tested this across Indonesian ports and hot, humid corridors.
Here’s the exact setup and the reasoning behind each choice.
The non-negotiables for frozen seafood
- Product must be fully frozen before loading. Hard at -18°C core or colder. The reefer maintains temperature. It doesn’t freeze product.
- Fresh air vent stays closed. Frozen cargo isn’t breathing. Open vents add moisture, frost, and energy burn.
- Air must circulate. Don’t block the T-floor. Fit the rear baffle so air can’t short cycle at the doors.
- Control to return air, not supply air. Return air reflects product temperature. Supply air will run colder during pull-down and defrost recovery.
We apply these to everything from Frozen Shrimp (Black Tiger, Vannamei & Wild Caught) to white fish fillets like Grouper Fillet (IQF), and tuna formats like Yellowfin Saku (Sushi Grade).
Copy/paste settings line you can send your forwarder
Use this as-is in your booking email or WhatsApp to the depot and trucking team.
- Commodity: Frozen seafood, hard-frozen
- Set point: -18°C return air (RA control). If shrimp or sashimi blocks, set -20°C RA.
- Temperature tolerance: RA ±1.0°C. Supply air may run up to 3–5°C below set point during pull-down.
- Fresh air vent: 0% / 0 CFM. Fully closed.
- Humidity control: Disabled. No dehumidification or humidification.
- Defrost: Auto/Demand. If fixed interval is the only option, set every 12 hours with hot-gas defrost. Drains must be clear.
- Fans: Continuous.
- Alarms: High RA alarm at set point +3°C for >3 hours. Low RA alarm at set point −5°C for >6 hours.
- Data loggers: Minimum 2. Place one mid-height on a center pallet, one near the doors, both shielded from supply air stream.
- Baffles and airflow: Fit rear door baffle. Keep 8–10 cm side clearances. No cargo against the ceiling. Don’t block T-floor.
- Loading: No pre-cool of empty container. Load only product at -18°C core or colder. Door open time <30 minutes. If longer, cycle unit off during loading to avoid coil icing, then restart immediately after closing.
- PTI: Full PTI within 24 hours of pickup. Attach photos of vent at 0%, door gasket, T-floor, unit serial number, and PTI printout.
If you need us to tailor this for a specific SKU or lane, just Contact us on whatsapp. We’ll send a one-line instruction you can forward to your carrier.
Pre-trip inspection (PTI) checklist we expect before accepting a box
From experience, 80% of frozen cargo issues trace back to airflow and drains. Here’s the PTI list we make the depot sign off on.
- Controller and sensors
- RA probe and SA probe pass calibration check.
- Controller firmware current. Unit acknowledges RA control at the chosen set point.
- Alarm test executed. Audible and visual alarms verified.
- Refrigeration and defrost
- Coil and drains clear. Water drains freely after a manual defrost test.
- Auto/Demand defrost enabled. If interval defrost only, set 12-hour schedule and confirm.
- Airflow
- Evaporator fans operational in all speeds. No unusual noise or vibration.
- T-floor unobstructed. Rear baffle present.
- Integrity
- Door gasket pliable and sealing. No light leaks on torch test.
- Fresh air vent sealed at 0%. No damage to vent door or cable.
- Pull-down test
- With ambient ≥30°C, box reaches and holds set point within manufacturer’s pull-down spec.
- Documentation
- PTI printout or PDF with RA/SA trend, defrost test record, alarm test record, and photos.
When any one of these is “almost fine,” we reject the unit. It’s cheaper than a claim.
Stowage pattern and airflow details that save loads
- Pallets and cartons: Use standard pallets with open deck boards. Align slats to run front-to-back so air can move up through the load.
- Side and top clearance: Leave 8–10 cm minimum on sidewalls and 10 cm below the ceiling.
- Door end: Always fit the rear baffle so cold supply air is forced through the load, not back to the return.
- Floor: Never lay sheets or slip-sheets that block the T-floor. If you must use slip-sheets, leave channels open.
In my experience, a perfect settings line can’t save a box that’s blocked airflow with flush-packed cartons or no baffle. This is where most “mystery hot spots” come from.
Practical answers to the questions we get every week
Should I set my reefer to -18°C or -20°C for frozen shrimp?
We recommend -20°C RA for shrimp. Shrimp benefits from the extra buffer against handling delays and door opens in tropical ports. For white fish fillets and portions, -18°C RA is fine. For sashimi-intended tuna blocks, use -20°C unless you’re on a specialized -35°C or -60°C program.
What should the fresh air vent be set to for frozen fish shipments?
Zero. 0% or 0 CFM. Frozen cargo doesn’t respire. Any vent opening introduces moist, warm air that increases frosting and energy use, and it can dry the product over long voyages.
Do I need to pre-cool the container or just the product before loading?
Do not pre-cool an empty reefer in humid conditions. You’ll load into a box full of condensation and ice the coil. Pre-cool the product to -18°C core or colder. Bring the container to the set point at the yard, then load fast. If loading will exceed 30 minutes in humid weather, temporarily switch the unit off while doors are open and restart immediately after.
How tight should the temperature tolerance be around a -18°C set point?
RA within ±1.0°C works well. We accept RA between -17°C and -19°C. Supply air will often run colder than set point during pull-down or after a defrost. That’s expected. Watch RA trends, not momentary SA dips.
How often should defrost run for frozen seafood to avoid snow build-up?
Use Auto or Demand defrost when available. If the controller only supports interval defrost, every 12 hours is a good baseline in humid Southeast Asia lanes. The real fix is drains that flow and a vent that’s closed. Excess frost usually means one of those is wrong.
What exactly should be on the PTI report before I accept the reefer from the depot?
- Confirmation of RA control and your set point
- RA and SA sensor calibration check
- Defrost test result and clear drains
- Vent set to 0% and sealed
- Door gasket and light leak test
- Pull-down verification to set point in ambient conditions
- Photos: serial number, vent, T-floor, baffle present, controller screen
Why does my logger show supply air colder than set point and is that a problem?
It’s normal. Controllers push colder supply air to get RA and product to the target. As long as RA stays in range and you don’t see extreme SA spikes for long periods, you’re good. If SA regularly drops below about -25°C, check for airflow short cycling or a faulty sensor.
When to deviate from the standard line
- Super-chilled or sashimi programs. Some buyers require -20°C RA for all tuna components like Yellowfin Saku (Sushi Grade) or Bigeye Steak. Align to the purchase spec.
- Glazed vs unglazed. Unglazed portions dehydrate faster. Keep the vent closed and consider tighter loading and more carton overwrap for products like Grouper Fillet (IQF) and Snapper Fillet (Red Snapper).
- Long dwell or transshipment ports. Use -20°C RA as a buffer and insist on a fresh PTI if the unit changes hands.
One trend we’ve seen the last few months is carriers standardizing “Auto/Demand” defrost and limiting pre-cooled empty pickups to reduce icing incidents. That aligns with the guidance above. Ask your forwarder to confirm the controller mode on the PTI.
Quick checklist you can tape to the loading dock
- Product at -18°C core or colder. Checked with a probe on a sample carton.
- Reefer set to RA -18°C or -20°C. Vent at 0. Auto/Demand defrost.
- Rear baffle installed. T-floor clear. Side and top gaps maintained.
- Two data loggers placed and started.
- Door open time minimized. If >30 minutes in humid weather, cycle unit off during loading.
- Photos taken of loading pattern and baffle.
We’re big fans of simple, repeatable process. That’s how we ship delicate items like Grouper Bites (Portion Cut) and premium portions like Mahi Mahi Portion (IQF) with consistent arrivals. If you want our lane-specific template for your buyer and route, Contact us on whatsapp. And if you’re exploring SKUs that travel well under this program, you can also View our products.