Thermal Insulation

 
Estimating the Heat Load on Your Refrigeration System
 
Try our Automatic Heat Load Calculator 

 

While some companies prefer to estimate heat load based on the volume (ie. cubic feet) of the ice box, we have found it more accurate to make the calculation based on the interior surface area. This method better estimates the additional heat load which occurs when an odd box size gives reduced volume but a large surface area.

Use the numbers below to estimate the total 24 hour heat load experienced by a couple living aboard in a tropical climate. First, measure your box to determine it's interior surface area (including partition dividers) in square feet. Then multiply it by the numbers below.

HEAT INFLUX PER 24 HRS., PER SQ. FT. OF INTERIOR BOX SURFACE AREA

Insulation "R" Value Insulation Thickness Refrigerator Box Freezer Box
10 2" 150 BTUs 280 BTUs
15 3" 120 BTUs 225 BTUs
20 4" 100 BTUs 185 BTUs
25 5" 90 BTUs 170 BTUs
30 6" 80 BTUs 160 BTUs
BARRIER ULTRA-R 1" 70 BTUs 150 BTUs

The performance given is based on the typical "R" value for good quality polyurethane foam board. Two-part "pour-in" foam and wet foam of any kind will have a lower insulation value. Do not base estimates on manufacturer's claimed "R" value unless you are certain that the testing method used has eliminated the influence of radiant type heat.

 

This information reflects data gained through tests conducted by Glacier Bay, Inc. and is distributed free of charge as an educational service to the cruising community. No aspect of this data may reproduced, published, distributed or referenced by any organization whether profit or non-profit without crediting Glacier Bay, Inc. as its source. Additionally, no profit making organization may do so without the written permission of Glacier Bay, Inc. To obtain such permission contact Glacier Bay, Inc. 2930 Faber St. Union City, CA. 94587 (510) 437-9100 P, (510) 437-9200 F, e-mail info@glacierbay.com
 

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