12" EB Wall with 4" EB Inserts
The EnerBlock design provides reliable, energy saving thermal performance. The insulation values of single-wythe EnerBlock Walls are in that optimum range which produces meaningful energy savings with fast payback of the cost of adding insulation.

West Materials believes it's important to state insulation values honestly and accurately, so that you can count on the data we provide. We could claim an incredibly high R-value if we did not use accurate calculation methods. However, a cross section of a concrete block wall is not uniform. There are webs, cores and mortar joints, each with different heat conductance rates through the wall. The most accurate way to measure thermal values of such an irregular construction is to test the entire wall assembly, using a guarded hot box test (ASTM C236). West Materials had an EnerBlock wall assembly guarded hot box tested to verify the thermal effectiveness of its design.**

However, in the interests of cooperating with industry efforts to achieve a uniform basis of comparison, our insulation value tables are based on the Series Parallel*** calculation method. This calculation method is now mandated in ASHRAE Standard 90.1, by the U.S. Department of Energy and by almost all state energy codes including Minnesota and Wisconsin.

While the Series Parallel calculations indicate insulation values slightly higher than those revealed by guarded hot box testing, they do measure irregular assemblies realistically for comparison purposes, and can be relied on for building design purposes.

** Tests for the EnerBlock Wall assembly using ASTM C236 Standard Method of Test for Thermal Conductance and Transmittance of Built-up Sections by Means of the Guarded Hot Box, were conducted by Twin City Testing Corporation, accredited for ASTM C236 by the National Voluntary Laboratory Accreditation Program.

*** Series-Parallel: Thermal values calculation as defined by NCMA (National Concrete Masonry Association) and ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers).
NCMA has developed a new evaluation program to document and report the R-values of concrete masonry wall systems that are constructed with integral insulation. Evaluation is available to NCMA members and non-members. The program is voluntary and is available for block producers and other associated companies that produce and market concrete masonry wall systems. The evaluation is not expensive.

KEY BENEFITS

    • Independent evaluation using accepted national standards required to address the entire concrete masonry wall instead of only separate components
    • Evaluation of insulation values by either of two accepted national standards:
      • Authentication of testing according to the ASTM C236 "Guarded Hot-Box" by an independent accredited laboratory at specific densities and properties
      • Accurate application of the Series-Parallel Calculation Procedure
    • Assurance of reliable insulation value data to meet energy codes for:
      • Architects
      • Engineers
      • Building Owners
      • Code Officials
Remember that the EnerBlock Insulated Concrete Masonry System places an insulating barrier between one block and the next horizontally. The space for that insulating barrier is only created as a masonry course is laid. Also, the crush ribs that assure insulation contact between courses must protrude vertically. Other polystyrene inserts placed in block voids at the block plant obviously can't protrude since they would be damaged in stacking and transit.

EnerBlock's continuous insulating barriers increase the R-value of a wall by more than 50 percent, compared with a wall not having insulation in the mortar joint areas. That, of course, is why it is so important to determine thermal effectiveness of an entire wall assembly, not just that of a concrete masonry unit.

12" EB Basement with 4" Inserts

Masons tell us that EnerBlock insulating barriers go in very fast, and that blocks without inserts are easier to grab and position.
EnerBlock wall section has sensors in place for guarded hot box test of thermal performance (ASTM C236). Test wall is four units wide by seven high, built with EnerBlock concrete block and EnerBlock insulating barriers. Note that the tested wall has standard mortar joints. Some block insert manufacturers only test dry-stacked surface bonded walls with no mortar joints.
EnerBlock R-values can be found on the TABLES page. Please select TABLES on the NavBar at the left,
or follow these links to the appropriate table:

Table One: EnerBlock Steady-State R-Values*
Table Two: Mass Adjusted R-Values
Table Three: Approximate Weight & Heat Capacity of EnerBlock Walls
Table Four: EnerBlock R-Values Without Grout or Reinforcing in Cores*
Table Five: EnerBlock R-Values With Vertical Grout and Reinforcing in Cores @ 48" Spacing*
Table Six: EnerBlock Foundation Wall R-Values
Cities with Degree Day Range

* NCMA evaluated R-values
Mass adjustment for concrete masonry is available because concrete's mass stores heat energy and releases it slowly when needed. This mass adds to insulation effectiveness. For example, a masonry wall with integral insulation in Washington DC with a steady state R-value of 4.8 is equal in insulation effectiveness to a light-frame wall with no appreciable mass with an R-value of 6.3 according to Table 502.2.1.1.2(3) of the 2000 International Energy Conservation Code.™

Mass adjustment needs to take into account heating degree days for various U.S. locations.

Using ENVSTD, COMcheck and other computer programs

Steady state insulation values should be used in code compliance computer programs such as ENVSTD (ASHRAE 90.1), COMcheck and REScheck. Mass adjustment is built-in for each city in these programs. These computer programs have built-in calculations for concrete masonry mass adjustments for most major cities in the U.S. Just enter the name of the nearest city representing the climate zone of your project. If the computer programs are not used, adjust for mass according to the International Energy Conservation Code (IECC) - see Table Two.