The thermal mass of concrete structures saves heating and cooling energy. It also significantly reduces indoor-temperature fluctuations and peak-summer temperatures.
Heat-insulating concrete saves time and money
Thermal masses can be actively used for night-time cooling or air heating, because the heating can be carried out with cheaper night-time electricity. With the help of a massive structures, free heat such as solar energy coming through windows and waste heat from household appliances can be stored and used. Underfloor heating works best when installed in a concrete structure. The charged heat is evenly transferred to the indoor air. Underfloor heating, placed in a concrete slab, can provide 80% of the energy needed for heating and water with cheaper night-time electricity.
The heat-storing capacity of concrete buildings
- Enables the usage of free energy accumulated by the building
- Saves 5-15 % of heating energy
- Levels and lowers indoor peak temperatures
- Saves 20-50 % cooling energy
- Can completely eliminate the need for cooling
- Applicable for low-heat technology (e.g. geothermal)
- Appicable for low-energy and passive houses
- Decreases the CO2 emissions emanating from buildings
- Reduces the cost of investment in mechanical, electrical and plumbing (MEP) technology
Mechanical ventilation benefits from hollow-core structures
In active systems, the cavities in hollow-core slabs can be effectively used as a ventilation duct. In this way, excess heat or coolness can be stored in the slabs, reducing summer-time maximum temperatures in the cooling needs of the building. Power demand and energy consumption for mechanical cooling are reduced and in some cases mechanical cooling can be completely eliminated by utilizing the thermal mass of hollow-core slabs. In this case, significant savings in both construction and operating costs are achieved.
Concrete soundproofs effectively
Requirements for both air-noise and footstep soundproofing have been specifically defined for residential buildings. Air-noise soundproofing depends on the mass and rigidity of the structure. Concrete walls and floors ensure good soundproofing. With hollow-core slab foundation and thick partitions, very good insulation can be achieved. With air-noise insulation, the tightness of the structure is of great importance, since even a small gap can significantly impair the insulation. Also in this regard, correctly made massive structures are more reliable than light ones.
Echoing under control with structural solutions
In the floors of apartment buildings, a cast-onsite concrete slab of at least 240 mm thick or a hollow-core slab weighing at least 500 kg/m2 with soft or hardwood flooring meets the current requirements for footstep soundproofing. When using mosaic hardwood, stone or ceramic tile as flooring, a floating-floor structure should be used. Acoustically and for the satisfaction of residents, a floating-concrete slab is the best option. In addition, often-harmful, low-frequency noises can be easily controlled with a concrete floor.