Reconstruct cold-room occupancy when warehouse throughput stays the same
Two cold-room days can have identical receipts, dispatches, opening stock and closing stock, yet different amounts of occupied storage time. A daily stock balance cannot recover when goods were present. Before explaining a warehouse electricity ratio, reconstruct that missing event sequence.
This original fictional exercise is for warehouse operations, inventory-control and reporting teams. It tests what movement records can establish about one room. It does not design an energy benchmark, allocate electricity to customers, assess cold-chain safety or recommend temperature or equipment changes.
Fix the room, the clock and the counting object
Compare two separate hypothetical days: A is 1 June 2026 and B is 8 June 2026. Each window runs from 00:00 inclusive to 24:00 exclusive at UTC+05:30. They are separate observations, not consecutive stock balances. The room is C in both cases; the illustration supplies complete and correct movement times and meter coverage.
C has 60 usable pallet positions throughout each day. Every pallet in this example occupies exactly one position while inside C. There are no split pallets, stacked pallets sharing a position, damaged-position closures, returns or unrecorded movements. Pallet identity is retained through any relocation within the room. These simplifying assumptions must be checked before using the calculation on real records.
EL-C records 480 kWh on each complete day. Its stipulated coverage is all electricity serving the single self-contained room C, including its lighting and refrigeration equipment, with no other zone or shared plant included. There are no additional supplies or exports. No interval electricity or pallet-specific measurement is supplied.
Read the daily summaries before looking at event times
On each day, the opening register contains 20 pallets, O01–O20. During the day, a different 20 pallets, N01–N20, enter C. All 40 eventually leave. Opening 20 + receipts 20 − departures 40 = closing 0. The distinct population present at some time is 40 pallets. Receipt plus departure activity is 60 pallet movements across the room boundary, because each new pallet contributes once on entry and once on exit.
Both days therefore produce the same daily summary. A reviewer with only these totals cannot tell whether the new pallets arrived before or after the opening stock left. Even a correct opening-to-closing reconciliation leaves that question unanswered. The following complete event records supply the missing order.
Reconstruct occupied positions between events
Day A: the 20 opening pallets remain until 12:00. The 20 new pallets arrive at 06:00 and leave at 18:00. Occupied positions are 20 from 00:00 to 06:00, 40 from 06:00 to 12:00, 20 from 12:00 to 18:00 and 0 from 18:00 to 24:00.
Day B: the 20 opening pallets leave at 06:00. The 20 new pallets arrive at 12:00 and leave at 18:00. Occupied positions are 20 from 00:00 to 06:00, 0 from 06:00 to 12:00, 20 from 12:00 to 18:00 and 0 from 18:00 to 24:00.
Treat each interval as including its start and excluding its end. A movement at 06:00 changes the occupancy for the interval starting at 06:00. It does not create an extra occupied hour at the boundary. At a simultaneous exchange, apply the complete set of movements at that instant before opening the next interval; do not invent a positive-duration state between simultaneous events.
For this diagnostic, one pallet-hour means one pallet position occupied for one hour under the stated one-pallet/one-position assumption. Multiply each interval’s occupied positions by its duration, then add the results. This is an original record calculation, not a prescribed warehouse reporting or allocation method.
Day A: 20 × 6 + 40 × 6 + 20 × 6 + 0 × 6 = 480 pallet-hours. Day B: 20 × 6 + 0 × 6 + 20 × 6 + 0 × 6 = 240 pallet-hours. Dividing by 24 hours gives average occupancy of 20 positions on A and 10 on B. Each observed occupancy remains within the 60-position capacity.
Check the same result by pallet cohort. On A, O01–O20 contribute 20 × 12 = 240 pallet-hours and N01–N20 contribute another 20 × 12 = 240. On B, the opening cohort contributes 20 × 6 = 120 and the new cohort contributes 20 × 6 = 120. The two routes to each total agree.
Do not require an arrival during the reporting day for an opening pallet to contribute time. Its residence interval is clipped to 00:00 at the start of this calculation. Similarly, a pallet still present at 24:00 would contribute through the end of this window without requiring a same-day departure. The opening register and the event list must work together.
Suppose N01 is relocated from position C07 to vacant position C19 at 15:00 on either day. That recorded handling task changes its position identifier, but the pallet remains inside C and occupies one position throughout. It adds neither a new distinct pallet nor another occupied position to this room-level calculation. A room-to-room transfer would require a different boundary check.
Keep throughput and occupied time as different observations
Using outbound pallets, both days give 480 kWh ÷ 40 = 12 kWh per dispatched pallet. Using occupied time, A gives 480 ÷ 480 = 1 kWh per pallet-hour and B gives 480 ÷ 240 = 2 kWh per pallet-hour. Neither arithmetic result is an electricity measurement for an individual pallet.
The first ratio is unchanged because the numerator and dispatch count are unchanged. The second differs because the event sequence halves occupied time while the stipulated electricity stays the same. The practical finding is precise: the identical daily summaries do not identify the occupied-time denominator. A timestamped movement history does.
Opening 20 and closing 0 also cannot establish average occupancy of 10 by taking their midpoint. That happens to match B, but it misses A’s 20-position average. Likewise, 40 distinct pallets × 24 hours would falsely assign a full day to every pallet and give 960 pallet-hours. Neither shortcut uses the supplied residence intervals.
The example supplies no temperature history, equipment duty, product arrival condition, weather or interval electricity. A higher kWh-per-pallet-hour display cannot establish a deterioration in equipment efficiency, and a lower value cannot establish a saving. In the empty intervals, the absence of stored pallets does not tell the reader how much electricity was used. No customer energy allocation follows from either ratio.
EPA’s August 2018 warehouse reference uses a statistical building model with operating hours, worker density, cold-storage share and climate terms. It does not validate the pallet-hour diagnostic here. The reference is context for keeping a simple operational ratio separate from a model-based performance assessment; no score, eligibility determination or Indian benchmark is calculated.
Ask for the records that can change the conclusion
Retain the room boundary and meter coverage, exact time zone and reporting instants, opening pallet identities, dated in/out events and any event corrections. Keep position changes available without treating them as boundary crossings. Record whether one pallet can occupy more than one position or be split; if so, reconstruct position occupancy explicitly rather than assuming the case’s one-to-one rule.
A missing movement time is not repaired by a matching daily balance. Hold the occupied-time result open, identify the affected pallet and ask the custodian for the event history or a separately justified estimate. A later export with the same total is not enough unless it supplies the missing order and dates. Preserve the original records when making a correction.
The review packet should let a second person reproduce both the event-by-event occupancy trace and the cohort-duration check. Ask them to remove the times and confirm that A and B then look identical. Restoring the times must recover the two different totals. This counterexample is the reason for requesting movement history rather than another daily throughput summary.
For the separate question of whether an operating change supports an energy-saving claim, see the energy comparison guide. For a portfolio that changes its property population, use the property comparison guide.
Discuss a bounded reporting-record review with Nitium Advisory using a non-confidential outline of the site, period and unresolved evidence question.
Source and limits
United States Environmental Protection Agency, ENERGY STAR Score for Warehouses in the United States, August 2018, printed page 6. The dated reference supplies context only.
Primary source checked 14 October 2026. All dates, pallets, movement times, capacities and electricity values are invented. No real facility, customer allocation, safety condition, carbon result, verified saving or independent assurance has been assessed.
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