Project details
Ambient conditions – where the room is located Enthalpy kJ/kg
°C
%
Room details Volume m³ · Floor m²
Transmission load W
U = 1 / Σ(thickness ÷ conductivity). Panel conductivities: PIR 0.022, PU 0.0253, EPS 0.038, XPS 0.030, XFLAM 0.031 W/m·K. The uninsulated slab on ground includes an allowance for ground resistance. Heat gain is taken as zero where the adjacent space is colder than the room. Use the floor "ambient" for the ground, sub-floor or floor-heating temperature (default 23 °C). Changing a panel switches the room-type defaults off.
Infiltration (air change) load W
Air changes per 24 h are from the standard ASHRAE table by room volume (above / below 0 °C). Usage factors: Long term storage ×0.6, Light ×0.9, Medium ×1.1, Heavy ×1.8, Extra heavy (2 main doors in use) ×2.2, or a custom factor. Heat removed per m³ is calculated from ambient and room air enthalpy (room air assumed at 75% RH).
Product load W
No product load has been calculated. Every room is built to cool product, so a product load is required: enter the product, the mass entering per day and its entering temperature above (or add a product).
+ Add product
Product load = sensible heat above freezing + latent heat of freezing + sensible heat below freezing, spread over the pull-down time. Respiration applies to the mass of living produce held in the room, at the room temperature.
Miscellaneous loads W
Summary
h / day
%
Required cooling capacity = heat load × 24 ÷ run time × (1 + safety factor). Typical run time 16 h for cool rooms and 18 h for freezers with defrost.
Incomplete calculation: no product load has been entered. The required cooling capacity below excludes the product load.
Capacity per floor area
W/m²
Capacity per volume
W/m³
Total heat load (24 h average)
kW
Required cooling capacity*
kW
* This calculation is provided by Refrigeration Distributors Pty Ltd (RDL) as a guide only, based on the information entered. Where no information is provided for a particular item, the calculation is based on the standard defaults only; for example, if no glass display doors are mentioned, no heat load for glass doors is included. It is the contractor's responsibility to verify the inputs, the results and the final equipment selection. This project has not been verified by an RDL engineer, so no responsibility will be accepted by RDL for any issues relating to system performance. RDL and all persons involved in the development of this calculator accept no responsibility for any loss or damage arising from its use.