Engineering Rome

Methods of Temperature Control: A Comparative Study between Ancient and Modern Rome

By Tristan Songer


In this comparative study, the differences in architecture, use of space, and technology used will be compared between ancient Rome and modern Rome along with the primary sources of pollution.

I. Comparison of emissions and air temperature

Before the comparison between ancient Rome’s and modern Rome’s methods of cooling and heating spaces is discussed a critical note must be made on the difference in emissions and causes of such and its relation to the air temperature. Within modern Rome, there are much more pollutants, emissions, and people than in ancient Rome due to the advances in technology and harsher forms of energy production that are used and though it may seem that modern Rome would be hotter due to these factors, the contrary is true. Lauren Lipuma, a writer, along with the American Geophysical Union, in an article on, gives an excellent explanation for this, “the pollution by the Romans is five to 10 times less than that due to the recent use of gasoline but it took place for a long period of time – several centuries instead of 30 years of leaded gasoline use.” While ancient Rome did not produce as much emission as modern Rome does per year, ancient Rome mined and produced harsh metals such as lead for over 500 years. According to Giulia Margaritelli, a geoscientist with certifications from the Research Institute for Hydrogeological Protection in Italy, ancient Rome was in fact hotter by 2 °C than average temperatures in the later centuries of Rome. Though, since fossil fuels and cars have become more common within the past several decades, greenhouse gas emissions have drastically increased causing summers to get much hotter in Rome.

II. Methods of cooling spaces in ancient Rome

In order to cool spaces down, such as homes, streets, villas, and public buildings, ancient Romans utilized architecture, water, and gardens or greenery. One of the easiest methods that were used to cool down the streets was designing tall buildings and narrow streets. This prevented a large amount of sunlight from hitting the roads which were often made of black volcanic tuff which easily collects heat. 

Images 1, 2, and 3 are examples of streets in Rome with tall buildings and narrow streets

The use of open spaces within the design of homes and villas in conjunction with gardens or green spaces proved to be an extremely effective method of cooling down both small and large spaces. These designs were often used in homes/villas of more wealthy Romans as they required the use of more space, material, and therefore money. Villas in themself are a perfect example of the excellent use of architecture with the purpose of cooling down the space with long lines of both covered and open walkways that control airflow which link with gardens planted with tall trees, bushes, or shrubs that provide shade. 

Image 4 of how a Villa is designed from Villa d’Este

In fact, the use of green spaces is essential as shaded surfaces can be anywhere from 11-25 °C cooler than the surrounding unshaded surfaces, and, “Evapotranspiration, alone or in combination with shading, can help reduce peak summer temperatures by 2–9°F (1–5°C)” according to the United States Environmental Protection Agency.

Image 5 from a large fountain overlooking ponds in Villa d’Este

Images 6 and 7 are of narrow pathways with bushes that provide shade and lead to water

Additionally, luxurious fountains cool the surrounding air temperature whether it be in a villa or in a public space, and let those who pass by drink or rinse. 

Images 8 and 9 are of fountains in Piazzi Navona (left) and the Trevi Fountain (right)

Master architects were aware of the effectiveness of using open space and greenery. This can be seen as ancient Rome has a large percentage of villas containing gardens and public green spaces in general. Below is a map of Horti Liciania, some of the major public gardens present in ancient Rome.

Image from Wikipedia.

One last method used to cool down spaces was developed from the cold and constant flow of water from the aqueducts. Cold water from the springs was sent down aqueducts and into lead or ceramic (terracotta) pipes which were built into certain parts of the inner section of walls. The cold water constantly traveled through the brickwork and combated the heating outside surface, decreasing the total amount of heat inside the home. An interesting thing to note is that ancient Roman architects took wall thickness into account depending on what type of building they were designing. This is an important concept to understand since stone acts as a phenomenal insulator and prevents heat from penetrating the stone for long periods of time keeping the inside cooler. You can see an example of this concept being utilized in the construction of the Colosseum. Since the walls are so thick and there is so much space within the walls on the bottom floor, the inside of the Colosseum after entering is considerably cooler than outside the walls. Many of these architectural designs are mentioned in the ten-volume book on architecture De Architectura, written in the first century by architect and engineer Marcus Vitruvius Pollio. 

Image 10 of the walls of the Colosseum

III. Methods of cooling down spaces in modern Rome

Obviously modern Rome has more and heavier emissions that pollute and increase the temperature hence the reason more costly methods that utilize electricity are taking place in order to combat the heat. Rome no longer has to utilize architecture on its own in order to cool down both private and public spaces as the development of electricity has provided some homes and buildings with air conditioning. Though, there are still several methods from ancient Rome that are still used today in modern Rome in order to cool spaces down. This is vital as electricity is expensive and not accessible in large amounts for every household and cannot be used to cool down outdoor spaces. In addition to this, most methods of producing electricity cause pollution (primarily from burning fossil fuels) which in turn results in an increase in temperature.

What’s different from ancient Rome:

  • Air conditioning
  • Fans 
  • Glass windows with shades

What’s similar to ancient Rome:

  • Gardens (as of 2017, 38.90% of Rome’s public spaces are gardens or green spaces (World Cities Culture Forum))
  • Tall buildings and narrow streets

Though, since the cost of importing and/or producing electricity in Italy is increasing and because the temperature within Rome is increasing since the drop in temperature that occurred after the highest temperature in ancient Rome during its imperial period, designing and implementing new methods of cooling the air temperature down could become crucial. 

III. Methods of cooling spaces in Rome in the future 

As temperatures rise and prices of electricity increase, Rome may have to once again rely on the use of architecture in order to maintain the temperature of the city. Fortunately, there are many methods to do so, some of which are currently being used once again by modern cities such as Madrid in Spain, and some methods that can be studied from other ancient civilizations such as Egypt or Persia (now known as Iran).

Madrid is currently planning to build a ‘Wind Garden’ inspired by ancient civilizations such as Egypt which is supposed to lower temperatures by 4 °C. It has a spiral design with mosses and ferns planted throughout the structure in addition to trees at the top that are supposed to catch the breeze from the wind and then draw the cool airflow down into the garden and the nearby streets (World Economic Forum). 

The image below shows an example of a ‘Wind Catcher’ from Yazd which is built above homes and draws in the air like a ventilator, cools it, and sends it down into the main rooms and the basements of the homes.

Image from Gate of Nations

Though, for a structure like the ‘Wind Garden’ or a ‘Wind Catcher’ to work in Rome, a new building would need to be built as these structures require a large amount of space and are often very tall and placing such a structure on top of a building could falter the integrity of the foundation. The problem is that these structures would be most effective in the center of the city where most of the people gather along with the heat, but Rome may not have the space to do so within its center or even its busiest areas.

Work Cited

Di Bernardino, A., Iannarelli, A.M., Diémoz, H. et al. “Analysis of two-decade meteorological and

air quality trends in Rome (Italy).” Theor Appl Climatol 149, 291–307 (2022).


Jaskol, J., “How Ancient Romans Kept Their Cool.” Getty, (2020).

Lipuma, L., “Roman mining activities polluted European air more heavily than previously

thought.”, (2019).

us%2C%20the%20pollution%20by%20the,years%20of%20leaded%20gasoline%20use %22

Margaritelli, G., Cacho, I., Català, A. et al. “Persistent warm Mediterranean surface waters

during the Roman period.” Sci Rep 10, 10431 (2020).

“A Magnificent Cooling Structure Called Wind Catcher.” Gate of Nations, (2019).

“Horti Liciniani.” Wikipedia, (2022).

“Madrid’s ‘Wind Garden’ Will Cool City By 4 Degrees.” World Economic Forum, (2022).



“The Project Gutenberg Ebook of Ten Books on Architecture,” (2006).

“Using Trees and Vegetation to Reduce Heat Islands” United States Environmental Protection

Agency, (2022).


“Welcome to the Gardens of the Roman Empire.” Gardens of the Roman Empire,

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