Is 100mm of concrete enough in air-conditioned buildings?

建筑师和设计师有时提出的一个问题是：“ 100mm的混凝土会提供足够的热量吗？”亚搏娱乐网站答案在很大程度上取决于您要在多大程度上优化建筑物设计的程度。可以认为100mm的混凝土足够，但是超过100mm的深度通常可以提供进一步的好处。这是由于热流往返混凝土的动态性质。在空调建筑物中，加热/冷却周期通常限制为24小时，因为对温度的更严格的控制应确保织物在织物中没有比一天更长的时间内的热量。

This might suggest that 100mm of concrete would provide the optimal level of thermal mass needed to reduce the air conditioning load. Whilst this may be true for a simple, flat concrete floor slab exposed on one side (i.e. the soffit), in practice slabs are often exposed on both sides and/or internally. This greatly increases the surface area for heat absorption and the effective depth of concrete that can be utilised in a 24-hour period, which in turn significantly increases the cooling capacity provided by the slab. This is commonly achieved by combining an exposed soffit with underfloor mechanical ventilation, enabling heat transfer from top and bottom surfaces of the concrete slab.

Similarly, another option is to have an exposed soffit in conjunction with hollow cores within the floor through which air is channeled, which is another way of maximising the heat transfer area. This technique forms part of the building’s mechanical ventilation system, which has the added benefit of ensuring air passing over the concrete is relatively turbulent, greatly increasing the rate of heat transfer at the surface and, as a consequence, the depth heat will penetrate during the daily cycle. It is worth noting that the 100mm benchmark sometimes quoted, assumes the use of natural ventilation i.e. smooth/laminar air flow at the surface, resulting in a much lower rate of heat transfer.

A further active cooling option that is increasing in popularity is the use of water rather than air to regulate slab temperature, made possible by embedding chilled water pipes in the soffit. Heat flow between the water and the concrete is by conduction, making it relatively rapid and enabling all the available thermal mass in the floor slab to be exploited.

因此，总而言之，无论是使用被动或主动的冷却方法，都可以充分利用具有超过100mm深度的混凝土地板板中的热量，以最大程度地利用冷却输出，并在炎热条件下提供增强的性能。亚搏娱乐网站有时建议，100mm混凝土提供足够的热质量非常简单，并且无法考虑到在实践中实际使用的地板以及它们必须操作的条件范围。亚搏娱乐网站有关更多信息，请参见Concrete Floor Solutions for Passive and Active CoolingandThermal Mass Explained。