Energy Conservation Considerations
Insulation can dramatically help to reduce cooling and heating loads, lower energy costs, reduce pollution and carbon emissions.
The maps below show the minimum R-Values that will be required under the new 2012 International Energy Conservation Code (IECC).
Energy Code/R-Value Map — United States
Source: U. S. Department of Energy [PDF]
| Climate Zone | ASHRAE 90.1 | ASHRAE 189 | |
|---|---|---|---|
| 1 | R-15 | R-20 | |
| 2 | R-20 | R-25 | |
| 3 | R-20 | R-25 | |
| 4 | R-20 | R-25 | |
| 5 | R-20 | R-25 | |
| 6 | R-20 | R-30 | |
| 7 & 8 | R-35 | R-40 | |
Energy Code/R-Value Map — Canada
Recommended minimums for all Canadian climate zones:
Roof Insulation: R-40
Wall Insulation: R-30
The status of conversion to the 2012 code recommendations will vary state-by-state or province-by-province. There is just not one code, but a number. Some have already updated their codes accordingly. Others have not. It will be necessary to see what progress your individual state or province has done in this regard. This can likely be done on the Internet, but if not available there, contact your local building department.
The type of insulation proposed for concrete walls shown in the details which follow will enable wall builders to meet the new energy code requirements in North America. Even the R-30 wall requirement will be readily achievable with these insulating foam-board forming panels.
The Role of Foamboard Insulation
Insulating forms for constructing reinforced concrete walls have been used in North America for nearly three decades.
Expanded foam rigid insulating boards have recently been introduced into the tilt-up concrete construction arena. They can be quite practical for insulating factory precast elements as well as tilt-up walls.
R-Values of concrete elements can readily be controlled by the thickness of insulating board used. It is mainly a function of the thickness of the insulating board panels specified. A rule of thumb suggests that one inch of expanded polystyrene (EPS) will represent an R-value of about 4. One inch of polyisocyanurate foam board is rated at R = 6.
The insulation does not perform a structural function — only energy conservation. It has been noted that some insulation board distributors imply disaster-resistant structural qualities to their foam board insulation while in reality the boards only act as forms into which concrete is placed.