Kelvin

Enter product, internal and defrost loads

The product brought in and held, its pull-down, freezing and respiration, and the lighting, people, forklifts, fans and defrost in the room.

Heat load and the cycle · Updated 7 Oct 2026

  1. 1

    Under Product, choose the product from the quick list, or type in Find in the reference library and pick a row.

  2. 2

    Enter the Incoming batch mass, its Entering temp and the Pull-down time for the batch.

  3. 3

    Enter the Total stock held, the stock already in the room. It gives produce's respiration heat.

  4. 4

    Set Freeze the product to Yes if the batch is to be frozen.

  5. 5

    Choose the Packaging and enter the Packaging mass.

  6. 6

    Under Internal loads and defrost, enter the lighting, people, handling equipment and evaporator fans, each with its hours, then the electric defrost.

Where the product's figures come from

The hint under Product gives its specific heats above and below freezing, its latent heat and its freezing point, with their source. A row picked from the reference library is copied into the room, so a later edit to the library never changes the room's figures. If the library can't be read, the quick list still works and nothing is estimated.

For a library row, Respiration offers the rows printed for that food. Choose the one your stock is, or none. The respiration rate is read at the room's temperature, for the stock held and for the incoming batch, and frozen stock doesn't respire. If the room is at a temperature the produce is damaged at, the load build-up warns you.

Freezing

Freeze the product adds the latent heat of freezing and the cooling below the freezing point. A batch that enters below its freezing point is already frozen, and takes only the cooling below freezing, however the switch is set.

Internal loads

  • Lighting density and Lighting hours. The page default density has no cited source, so use the job's lighting layout.
  • People and Occupied hours. The hint gives one person's heat at the room's set point, which rises as the room gets colder.
  • MHE units, MHE heat output and MHE running hours, for forklifts and other handling equipment.
  • Evaporator fan motors and Fan run hours. Enter an estimate, then the chosen evaporators' fan input once they are selected. Equipment doesn't fill it in.

Each internal load counts its heat over its hours each day, averaged over 24 hours.

Electric defrost

Turn on Electric defrost and enter the Heater rating, Cycles / day and Duration. Then choose its Sizing basis:

  • 24 h average addition puts all of the heater's energy into the room as heat, averaged over the day.
  • Peak recovery addition counts the heater's full rating as a steady load all day.

Both are conservative bounds, not measured shares. With defrost off, or no heater rating entered, none is counted.

How fast the batch itself cools is a separate question: see Work out a product's cooling and freezing time.