Home / Tools / Load Calculator

Cold Room / Walk-In Heat Load — sized to ASHRAE

Tool · 01 of 06
Step 1

Pick an application

We'll set typical defaults for your application — you can change anything.

Step 2

Room geometry

ft
Internal length, wall to wall.
ft
Internal width, wall to wall.
ft
Internal height, floor to ceiling.
Box location
Step 3

Conditions

Auto-fills ASHRAE 0.4% design dry-bulb. Override below if needed.
°F
%
°F
%
Step 4

Walls (Foster PU panels)

U-value computed live below.
Floor type
Above-grade floors lose more heat (no ground sink). Insulated slab is the premium build for freezers.
Step 4c

Doors & infiltration

ft
ft
Reduces door air exchange by ~50% (E factor per ASHRAE Refrigeration Ch. 24 Table 14).
Step 4b · Advanced

Wall sections (optional)

Step 5

Product load

Daily throughput cooling + respiration heat for live produce. ASHRAE Refrigeration Ch. 19 thermal properties database (222 products).

Step 6

Internal loads

W/ft²
Modern LED installs run 0.6–0.9 W/ft².
h/day
count
h/day
kW
Defrost
Step 7

Safety & run-time

Safety factor
Usage intensity
Door usage / traffic. Heavy = busy retail / loading dock.

How this calculator works

The heat load calculator applies the five-component method from ASHRAE Handbook — Refrigeration 2022, Chapter 24: (1) transmission load through walls, floor, ceiling, and doors using the entered panel U-values; (2) infiltration load via the Gosney & Olama (1975) empirical ACH model adjusted for door width, height, and protection factor; (3) product pull-down load from entered commodity, initial temperature, and pull-down period; (4) internal gains from lighting, motors, and occupants; (5) a 10% safety factor. Ambient design temperatures for major U.S. metros use ASHRAE 0.4% design dry-bulb values. Panel U-values are calculated from entered thickness and λ = 0.022 W/m·K (ASTM C518 declared aged value for Foster's foamed-in-place polyurethane panel). Results are validated within ±20% of Heatcraft NROES, Copeland AE-103, Danfoss Coolselector®2, and Bitzer Software for typical commercial walk-in geometries.

References: ASHRAE Refrigeration Handbook 2022 Ch. 24; Gosney & Olama (1975) Int. J. Refrigeration; ASTM C518; IEC 60335-2-89:2019.