Energy efficiency and SCIPs, SIPs, and ICFs

 

SCIP Panels

Structural Concrete Insulated Panels

There is a fair amount of misinformation about energy efficiency and SCIPs, SIPs, and ICFs

So here are two links for starters http://www.ornl.gov/sci/roofs+walls/research/detailed_papers/thermal/index.html

Although the words SCIPs SIPs and ICFs are not used if you know the products you know what and the difference between them are,

  (Walls containing foam core and concrete shells on both sides)

(Concrete wall core and insulation placed on both sides)

(Walls where the insulation material was concentrated on the interior side)

(Comparative analysis of sixteen different material configurations showed that the most effective wall assembly was the wall with thermal mass (concrete) applied in good contact with the interior of the building. Walls where the insulation material was concentrated on the interior side, performed much worse. Wall configurations with the concrete wall core and insulation placed on both sides of the wall performed slightly better, however, their performance was significantly worse than walls containing foam core and concrete shells on both sides)

Most of the misinformation is about the wire trusses going from one side of the panel to the other. They make un substantiated claims so here are some facts

1.            ORNL conducted thermal experiments in 1987 that tested concrete sandwich panels:

 

http://www.ornl.gov/info/reports/1987/3445602788810.pdf

 

a.      This paper states that there is only a 7% reduction in the thermal properties of concrete panels with 32 – 3 mm diameter stainless steel connectors in a 103”x103” wall compared to walls without connectors or with fiberglass-composite ties.

b.      The report evaluated the isothermal planes method (also called series-parallel method) of calculating the R factor for the wall assemblies and found that the method predicted a 5% decrease in the thermal properties which is very close to the measured difference.

c.      The isothermal planes method for concrete walls is contained in ACI 122R “Guide to Thermal Properties of Concrete and Masonry Systems” which we used to calculate the R-factors for the GCT TER.

d.      The walls also had a thermal lag of 5 to 6 hours, which helps to reduce the impact of daily high/low temperatures.

e.       The thermal lag indicates the capacity of the wall to store energy and is useful for designing passive solar systems.