VIP vs PCM: How to Choose Pack‐Outs by Lane Heat Load (with Hold‐Time Math)

Why brochure hours mislead: Vendor specs assume ideal ambient and perfect conditioning; your lane doesn’t. Model Tambient profile, asset U/R‐value, coolant mass, and product mass.

Step 1 — Define lane heat: origin cut‐off dwell, ramp exposure, hub dwell, last‐mile ambient. Build worst‐case.

Step 2 — Pick asset class: VIP+PCM when dwell > 36–48 h or ramps are volatile; PCM only for ≤ 24–36 h with tight handovers; dry ice for −20 °C storage, frozen with venting and mass updates after re-icing.

Step 3 — Hold‐time sizing: Compute heat gain Q = U·A·ΔT·t; size coolant such that Q ≤ m·L (PCM latent heat). Add 15–20% buffer.

Step 4 — Conditioning & loading: Pre‐condition PCM to phase window; verify polarity pattern; place temp logger centrally; void‐fill properly.

Step 5 — Telemetry triggers: Caution Ttarget +1.0 °C; re‐ice at ≤ 25% remaining hold‐time; escalate to buffer site or asset swap if forecast dwell exceeds hold‐time.

Worked examples: RTC metro‐to‐metro (24 h → PCM 24–36 h +20%); Tier‐2→EU (36–60 h → VIP 60–72 h+20%); Frozen −20 °C (dry ice mass sized to worst‐case dwell +20%).

Quality controls: Shock/tilt indicators; don’t tender if indicator tripped; label/app/device parity.

Reach out to us today and share your lane details for a 48-hour hold-time specification.