About a third of households have bought a fan. Is it better than doing nothing about the heat? It is definitely better. A fan can really help with air circulation and we feel better even though it does not completely remove the heat. But when air circulates, we feel that it is better.
For example, if we try to put a bottle of frozen water or a wet cloth in front of the fan, it can help even more.
What architectural measures can be taken on an individual basis if we already own an apartment or house and are willing to renovate? First of all, I would start with insulation. Although we usually call it thermal insulation, insulation works very well even in the summer, when it lets the heat out and keeps cooler air inside for a longer period of time. And I would replace the windows with triple-glazed windows or new windows. I understand that this is a longer-term project and that it costs more money.
A less expensive measure is outdoor blinds or outdoor shading. These can be roller blinds, venetian blinds, roller shutters or even traditional shutters, if we are talking about more traditional houses, they are suitable there. These are the basic measures that have the greatest effect.
If the house has all this, it is already insulated, it also has an insulated roof, but it is still hot there, then air conditioning comes into play. This is a very functional technology that we know from southern states and the like. It is a good solution for heat waves when it is 40 degrees outside and there is no other way to solve it.
Air conditioning in second place
But you did not mention air conditioning in the first place. I do not recommend it in the first place. Passive means – that is, insulation or shielding – work better in the long run and do not have such high operating costs, because I do not have to constantly run electricity into them.
At the same time, the human body also feels better in it. Many more sensitive people – and it happens to me too – then get a cold from air conditioning. For this reason, I prefer the option of insulation, better windows and external shielding.
For example, in our apartment it works. We have found that when it is thirty degrees outside, it needs to be twenty-seven inside. And 27 degrees is something that in extreme heat – when it is thirty-eight outside – I consider to be a decent temperature at which we can function.
But you can't sleep in it. You can't rest at twenty-seven degrees, right? It's more demanding. I can confirm that the last two nights were more demanding for us too. In our case, it's not worth buying air conditioning yet, but I don't rule out that we will use it at some point in the future if the situation worsens.
What to think about when planning a new building?
We talked about reconstruction, but what to think about when planning a new building? Climate change is raising temperatures and extreme heat waves will probably increase in the future. Fortunately, Czech legislation already considers that new family house construction must be low-energy and therefore very well insulated.
If you have an architect or designer design your building, the building is already well insulated. And at the same time, it usually comes down to the fact that it should have a smart ventilation system with heat recovery, which together keeps the air inside cooler than outside.
Then it is possible to install more modern heating and cooling methods together. Very often, these are systems based on cooling the air, or using, for example, an air-to-water heat pump, which can also cool.
These are simply more sophisticated methods than how we imagine classic air conditioning – a box that we buy somewhere and then install. Modern houses, often in the passive building category, already have this solved very well and can maintain a stable temperature for a long time.
I would recommend that you also think about the color of the roof and facade when building a new building. This is exactly what can be influenced well. Scientists from the Academy of Sciences have measured that a white or light-colored roof is really the best at reflecting light rays, and therefore heat, and it does not heat up as much.
If you can choose a lighter roof and a lighter facade, it is definitely better than completely dark houses.
Let's touch on rental housing. What cheap interventions would you recommend to people, for example seniors in a rented city apartment that is overheating? Is there a way to solve this? In the long term, I would recommend that they contact the city that rents them the apartment, and that the city install external shading for them, for example. In the short term, I definitely recommend putting some shading on the outside of the window, even improvised ones.
People put white sheets or shading foils there, which can be stuck to the window. Or even aluminum foil, which has the disadvantage that it reflects light back out, but light, and therefore heat, does not get inside.