What an annoying sensation, jumping like a lizard on a frying pan when walking to the swimming pool! In large leisure and tourism areas, such as water parks, the distances grow and the problem gets worse! Well, there are different strategies to combat this, but they are not mutually exclusive: shade, colour, porosity, material and fluid circulation are some of them.
The first obvious solution is to shade surfaces to prevent them from heating up. To this end, vegetation and/or a range of shading systems can be used (which, by the way, we discussed in a previous article which you can access via the link below). However, neither vegetation nor shading systems guarantee total coverage of surfaces. Also, in other leisure and tourism areas such as beaches and sunbathing areas, the sun is desired.
In this case, the most effective measure to mitigate the heating of a surface is undoubtedly the choice of the colour of the flooring. One with a good SRI (Solar Reflectance Index) reduces the energy captured by the floor by up to 20% and therefore its temperature. Below in Figure 1, you will see a typical colour chart with SRI data.
Figure 1. Printed concrete colour chart with SRI data.
However, sometimes, for aesthetic or comfort reasons, to avoid glare, we cannot use light colours. So, to solve the problem of the “lizard in the frying pan”, this is when we resort to the porosity of the flooring in leisure and tourism facilities.
The porosity of the floorings means that they offer less mass to accumulate heat. At the same time, as their surface area increases, so does their emissivity and, therefore, heat dissipation. With regard to porous materials, we have “athermal” tiles manufactured with the addition of volcanic aggregates (very common in South America) or with porous concretes (more common in Europe). Volcanic aggregate tiles (Figure 2) are more suitable for private pools and small surfaces, as they tend to accumulate more dirt and, therefore, in a large surface such as a water park, they require more maintenance work.
Figure 2. Tiles made from volcanic aggregate.
Porous concretes (Figure 3) have the advantage in that they can be produced in a wide range of colours. In addition, their roughness makes the surfaces of wet leisure and tourism environments such as water parks slip resistant. Another advantage is that they allow the ground to drain through them and therefore reduce run-off water (although this does not totally dispense with specific drainage). Porous concretes are also widely used in sports fields and urban environments to combat the “heat island” effect.
Figure 3. Swimming pool with porous concrete.
Another approach to the problem is to act on the finishing material. Synthetic materials accumulate less heat than cement-based materials. Therefore, the most common strategy is to use either a Kool-Deck coating (originally a brand name, now a generic name) or an acrylic finish. Kool-Deck (Figure 4) has a better performance for temperature reduction. On the downside, it can lose its colouring over time and it requires specialised application on fresh concrete. The acrylic solution is more expensive, but more durable, which is why it is the most widely used today.
Figure 4. Pools with the typical Keystone texture of the Kool-Deck system.
Another option to avoid the “lizard in a frying pan” effect, from a material point of view, is the use of natural stone (Figure 5). There are some types of stone that are widely used in swimming pools, such as calcarenites. Although it may seem that their cost will be high in large leisure and tourism areas, such as water parks, their installation however may be feasible if alternated with other solutions, depending on their design and location.
Figure 5. Albamiel Stone by Rosal Stones.
Finally, we have a technological option to address the issue. It consists of cooling the flooring, in the inverse manner to what occurs in radiant floors for heating, by means of the internal circulation of a cold fluid (Figure 6). The disadvantage of this system is that its cost is high, so it is not very viable for large surfaces.
Figure 6. Cold fluid circulation cooling system.
There are other forms of flooring cooling, such as misting or sprinkling of surfaces at certain locations in the leisure and tourism facility and at certain times of the day. These may or may not be used in combination with the above. However, these alternatives have a negative impact on water consumption.
In conclusion, there is no single solution for temperature reduction of flooring exposed to solar radiation. The choice of the most appropriate system will depend on the circumstances of each project, as well as its location and the availability of the materials to be used.
As promised, you can access our review of the shading systems through this link.
By Miquel Solís, senior architect in the Architecture Department of Amusement Logic
