The concept behind this novel block is to produce a structural element similar to the existing HCB, but with greater thermal properties. AB ThermaBlock is made out of three elements; a load bearing brick which has known qualities of thermal inertia, which acts as a heat sink, in summer and winter, an insulation layer and a protective skin on the outside. The air cavity is retained to assist in thermal performance, reducing thickness of insulation as well as acting as a moisture barrier.
After identifying the shift towards energy efficiency, particularly with the introduction of insulation products in construction, Attard Bros. recognized the need to have a block with mechanical properties similar to standard hollow core blocks but developing it to be a building element that also maintains ‘quasi-ideal’ temperature closer to the thermal comfort range inside a building.
The AB ThermaBlock is a sandwiched precast concrete block cast using normal density limestone concrete aggregates, ordinary Portland cement and an insulated layer of medium density expanded polystyrene. The combination of the factors mentioned in the short desciption above, helps in absorbing and moderating any temperature fluctuations that occur in peak summer and winter months. Limiting such temperature fluctuations also limits the demand for cooling and heating, thus curtailing energy bills. This also means installing HVAC equipment of a smaller capacity. Both of these effects create an immediate economic advantage and a long term environmental benefit.
The AB ThermaBlock is manufactured in a production process similar to standard hollow concrete blocks. The manufacturing process is controlled by Quality Assurance procedures conforming to ISO 9001:2008, ensuring constant, top quality production. The dovetail design of the expanded polystyrene layer combined with the substantial compaction generated by the block making machine during the manufacturing process, ensure that the insulation panel secures the load bearing concrete hollow block and the non-load bearing block together.
The Fraunhofer Institute for Building Physics was ordered by Attard Bros to calculate the equivalent thermal conductivity λeq, the thermal resistance R as well as the thermal transmittance
U of masonry made of AB ThermaBlock for mortar-mix by thin-bed mortar. The calculations were conducted by means of 3-dimensional Finite Difference Method. With its low U-value (which is a measure of the quantity of heat transferred through the material per unit area when the air temperature on either side differs by one degree [W/m²K]) of 0.68W/m2K, the AB ThermaBlock provides superior energy reduction on what is legally required, i.e. minimum requirement U-Value of 1.57W/m2K.
Barriers and Drivers
The latest revised Building Regulations for Malta highlight ever more the need for a holistic environmental design solution to any building. Moreover, this has now become enforceable under the Legal Notice, LN 261/08. Minimum standards of energy performance for the different building elements are spelt out; these are to be adhered to as mandatory. An EPC (Energy Performance Certificate) is now required for practically every building. This is similar to energy labels used on domestic electrical appliances.
Nonetheless, the inertia of this shift is impeding the product being from astonishingly successful. Even though there is a legislation that had been passed way back in 2009, houses are still being built not conforming to the legal requirements, because there is not enough enforcement of the law. Malta needs to start building for the future, only enforcement will get the people to abide by the set laws.
Value Added - When considering the total cost involved in purchasing and maintaining a property, building green enhances the value of investment of the property to its buyer.
Reduced Labour Costs - Thanks to its innovative 3-in-1 form, AB ThermaBlock arrives at the development site ready to use, reducing costs associated with transportation and construction effort.
Faster Construction Time - Since AB ThermaBlock brings together 3 building processes in 1 thanks to its form, construction time is greatly reduced.
Space Saver - Building with AB ThermaBlock increases the space available inside a property. The AB ThermaBlock is 28% slimmer than other insulation building methods. Thus a perimeter strip of space is gained all around external walls.
Sound Attenuation - Thanks to AB ThermaBlocks’ 50mm layer of polystyrene, sound passing through walls is reduced.
Increased Thermal Comfort - A wall built with AB ThermaBlock creates a thermal barrier. Heat transfer through external walls can be reduced by up to 57% (when compared to a wall with a U-value of 1.57W/m2K) hence reducing the monthly energy costs related to both heating and cooling.
Seasonal Adaptability - AB ThermaBlock offers advantages in both the scorching summer months as well as the lean cold months of winter.
Reduction in temperature fluctuations - AB ThermaBlock reduces peak loading times for heating and cooling. This results in smaller HVAC equipment required and low power consumed, thus yielding to lower investment and running costs respectively.