The following table shows the values concerning the heat transfer of a freezer.

Item Value Unit Value Unit Value
K 0.4 W/m2·K 1.29 kg/m3 kg/m3
F 0 m2 0 m3 m3
FS 0 m2 1000 J/kg·K J/kg·K
Fd 0 m2 2258 J/g J/g
tw 30 6.82 g/m3 g/m3
tn 4 0.77 g/m3 g/m3
△tS 20 8 % %
L 2.1 h-1 7.5 W/m2·K W/m2·K

K—coefficient of heat transfer in the freezer body (W/m2·K), almost unchangeable when the structure, thermal insulation material, and technology of the freezer are defined

F—heat conductive area (m2), the geometric mean of the inner and outer surface area

FS—basked area (m2), usually the half value of F

Fd—door area (m2)

tw—the temperature outside the freezer (℃)

tn—the temperature inside the freezer (℃)

△tS—temperature increased under the sun shining (℃)

L—air leakage ratio (h-1), also unchangeable like K when the structure, thermal insulation material, and technology of the freezer are defined

ρ—air density (kg/m3)

V—air volume inside the freezer (m3)

C—specific heat of the air (J/kg·K)

φ—the heat of evaporation of the water (J/g)

Xw—the water content of the outside air (g/m3)

Xn—the water content of the inside air (g/m3)

ψ—time occupancy of the door opening (%)

α—convective heat transfer coefficient (W/m2·K)

Freezer trailers are designed for the transportation of frozen foods. They are adopted in the cold chain and home delivery service. In the past, the heat transfer in a freezer is defined by experience only, for the actual value usually asks a lot of data support. With the increasing demand for green transportation and lightweight vehicles, the precise calculation is more and more necessary in detail. With advanced technology, TOPOLO is able to make it.

Materials of Freezer Trailer Panel

PU foam: the 1:1 combination of isocyanate and premixed polyether

PU foam keeps the popularity in temperature-controlled transportation materials. It is an ideal material for temperature keeping and heat insulation. With high strength and manufacturability, PU foam is suitable for freezer trailer panels and is widely used in China and many developed European countries.

Extruded PE: an advanced heat insulation material in the world market

It is lightweight and water free, high-strength and non-toxic, low cost and easy to form. It costs less than PU foam and demands less in process. Extruded PE is a future material in dry van body panels.

How to Define the Heat Transfer of a Freezer


English EN French FR Japanese JA