While many people in developing countries can see the benefits of using insulating concrete formwork (ICF) in new construction, the problem comes to the effectiveness of ICF in tropical climates. Ghana is a tropical country with temperatures ranging from 70 to 90 degrees Fahrenheit (21 degrees Celsius to 32 degrees Celsius) and high humidity. There is little difference between day and night temperatures. ICFs, which have been shown to work well in seasonal climates, also work well in tropical climates.
Insulating concrete forms (ICFs) are blocks of foam that stay in place and are stacked to form structural foundations and walls. Once the rebar is in place, concrete is poured into the cavity creating a solid 10.16 cm (4 in) concrete wall with 6.35 cm (2.5 in) of insulation on each side. This creates a robust and energy efficient building (R 22 value).
The 10,16 cm (4 in) solid concrete wall forms a thermal mass for the home. It takes a long time for the thermal mass to heat up. Concrete is a good thermal mass material because it is a slow conductor of heat. If protected from the sun, the concrete of the walls effectively prevents the heat of the climate from entering the interior space of the building. The shadow is produced by the 6.35 cm (2.5 inches) of insulation on either side of the concrete wall. Once the house or building is constructed, the ICF block remains in place allowing the expanded polystyrene (EPS) panels to serve as building insulation.
Ghanaian builders typically build houses from uninsulated concrete blocks. ICF’s concrete houses would be surrounded by expanded polystyrene (EPS) insulation. EPS is used in cold storage facilities, mobile reefer containers, and commercial grade refrigerators. Food placed inside coolers stays cold for long periods of time, especially with the addition of an ice pack. Like the items in the refrigerator, the people in ICF homes and buildings would stay relatively cooler than in conventional homes and buildings.
Some builders in Ghana simply resort to applying EPS panels to the walls of concrete block buildings. While this construction method produces a better building than concrete block alone, it still uses the same labor-intensive concrete block construction method and reduces the benefits of having a solid concrete wall.
ICFs are much lighter than concrete blocks, weighing only 6.5 pounds per ICF block. Due to the weight, less endurance or muscular strength is required to become valuable workers. A team used to building with concrete blocks can easily transition to ICF blocks. Each ICF block covers 0.495 square meters (5.33 square feet) of exterior wall space. Houses are built in half the time that of concrete blocks and a building is produced that is structurally sound. ICF homeowners experience cooler and more uniform temperatures in tropical climate areas. If the homeowner chooses to install a cooling system, the homeowner will experience a reduction in the need to operate it. Due to the resistance to heat transfer found in ICF block construction, ICFs are beneficial in all new construction in Ghana.