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Thermal Mass Info - T2 Advantages - The T2 System Background
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Comparative Analysis of Concrete Insulating Configurations
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The thermal advantage of insulation applied to the exterior of a concrete wall is a phenomenon known as thermal inertia, more commonly referred to as thermal mass effect. Thermal mass effect is simply the ability of concrete mass to absorb and store heat. When concrete is used as a wall structure in a building this ability to absorb heat and the placement of the insulation has a profound effect on the building’s performance. When insulation is placed on the exterior of the wall the heat generated in the building conducts through the concrete mass first before meeting the resistance of the insulation on the exterior. If the insulation is sufficient to meet the heating demand on the building the concrete mass will warm to close to room temperature while storing millions of BTU’s of heat energy between the building occupants and the outside elements. This stored heat effectively creates a comfortable living environment by stabilizing indoor temperature fluctuations and reducing condensation. When the cooling of a building is of more concern than heating, the concrete mass can remove unwanted heat from the air reducing the need for air conditioning.
- When the insulation applied to a concrete wall is divided equally between the interior surface and the exterior, as in the case with typical insulating concrete forms (ICF), the effectiveness of thermal mass in stabilizing the indoor temperature is not as great. While the benefit of thermal mass is still a key element in the energy performance of these systems the inner layer of insulation compromises the ability of the mass to work to full potential. By using the inner foam layer in the forming process the concrete mass is isolated away from the living space. As the heat demand on the ICF building causes the heat energy to transfer through the wall the first layer of insulation sets up the initial resistance. Once the energy has passed through the inner layer of insulation it is absorbed by the mass of the concrete. Since the layer of insulation applied to the outside governs the rate at which the energy passes through the concrete mass the mass in an ICF building is only protected from the elements by ½ of the building’s insulating potential. Temperature stability resulting from heat radiating from the mass into the living space or absorption of unwanted heat cannot happen in an ICF structure.
- When the insulating layer is placed only on the interior side of a concrete wall the thermal mass element is the least effective compared to the other methods of insulating a concrete structure. In a warm climate exterior mass has some benefit due to its ability to absorb heat during the day and release this unwanted heat back to the atmosphere at night. The interior insulation would help to reduce the transmission of this daytime heat to the living space. However residual heat that did find its way into the building, for example through windows and opening doors would stay in the air and raise the indoor temperature quickly if not air-conditioned. These buildings would be more effective in cooling if they had no insulation at all. In the case of a colder climate the insulation on the inside actually puts the thermal mass in a negative position. The insulation adjacent to the wall will keep heat inside giving the space a warm feel but, considering that the down swing to the night time low temperature and the upswing to the day time high is between 12 and 16 hours the concrete mass can be subjected to prolonged cold temperatures even if the daytime high is relatively comfortable. What happens to these buildings is the heat loss potential is determined by the differential in temperature between the cold concrete and the desired indoor temperature and not a fluctuating rate between indoor and out door temperature as would be experienced with a wood structure that has no real thermal mass.
The T2 System - Thermalwall Technology
Thermal Mass Info - T2 Advantages - The T2 System Background
T2 Business Model - Mission Statement - Contact