About Thermacell

R Rating

The table below shows the calculations used to determine the estimated 'R- values’ for the four types of Thermacell wall configurations. The effective R-value of a wall system may be estimated by the sum of the R-value of its component parts.

Some assumptions must be made that will differ from any particular installation so an exact value will only be obtained from measurement of the whole system under the conditions of use.

In the figures shown, winter conditions have been assumed @ 22oC inside and 12oC outside.

Wall
Components
K
Value
R Value
125mm
R Value
150mm
R Value
200mm
R Value
250mm
Outside air film 0.0240 0.02400.02400.0240
5mm Cement Render 0.0030 0.00300.00300.0030
75mm Concrete fill
83.5% of cross section
1.770.0353   
82mm Concrete fill
83.8% of cross section
 1.77  0.0390  
99mm Concrete fill
84% of cross section
1.77    
120mm Concrete fill
89% of cross section
1.77  0.0603 
180mm Concrete fill
91% of cross section
1.77   0.0823
EPS Faces
2x @ 25mm ea.
0.03501.428   
EPS Faces
2x @ 32mm ea.
0.0350  1.829  
EPS Faces
2x @ 33mm ea.
0.0350    
EPS Faces
2x @ 40mm ea.
0.0350  2.286 
EPS Faces
2x @ 45mm ea.
0.0350    3.482
EPS Struts 75mm long
16.5% of cross section
0.03500.353   
EPS Struts 86mm long
16.2% of cross section
0.0350  0.398  
EPS Struts 99mm long
16% of cross section
0.0350    
EPS Struts 120mm long
11% of cross section
0.0350  0.377 
EPS Struts 160mm long
9% of cross section
0.0350    0.429
50% of 2mm air space
& 10mm Plasterboard
 0.028 0.0280.0280.028
Inside Air film 0.1 0.10.10.1
      
OVERALL R VALUE 1.97 2.422.88 3.50

The following extract is from Styropor News(R), June 1993, by BASF Australia Ltd.

Q: How effective is EPS (expanded polystyrene) as a thermal insulation material?
A: Extremely effective ... essentially because stabilised air is such a good insulator.

The thermal performance of a material is measured in terms of its resistance to the flow of heat. This thermal resistance is expressed in R values; The higher the number, the better the insulation.

The R value of the most commonly used class is 0.57 for every 25mm of thickness.

Thus, 44mm of EPS delivers an R value of 1. By comparision, 1,240mm of concrete is required to provide the same R value.

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P.O Box 447
Somerville
Victoria, 3912
Australia
Phone: (03) 5977 7996
Mobile: 0414 664 500

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Recommended Builders

Over the nearly thirty years Thermacell has been in business, we have worked with several different builders, construction companies and tradesmen. We have compiled a list of just some of these builders and tradesmen Read More

IMPORTANT INFORMATION

There is a company in Perth W.A. calling itself Thermacell I.C.F. International. We wish to advise that this Company has no affiliation with Thermacell Australia, and that we are not responsible for any of their marketing activities. We advise that any enquiries for dealerships or product sales must be made through our head office in Victoria where it has been since 1985