## 1 Introduction
Consequently, this generated the need to use specific and uninterrupted air conditioning systems, which, due to their operation, increased electricity costs even more. As stated by [PERSON] et al. [27], the energy cost of a data center is responsible for approximately 50% of its total operating cost. According to [PERSON] et al. [28] and [PERSON] et al. [29], cooling systems tend to be responsible for the slice of about 40% of all energy consumed by data centers, being only behind the numbers of electrical consumption needed to power the servers, network assets, and other equipment directly linked to the operation of the systems and services. The improvement projects that bring a cost reduction of air conditioning consumption in the data center are critical success factors to better energy efficiency in environments like this, significantly if these improvements also extend equipment life without direct electrical power from the data center. It is a consensus in the literature and practice of data centers that the most impact factor in energy consumption is maintaining the temperature at adequate levels [30; 31; 32]. The strong dependence on temperature and energy consumption in semiconductors was demonstrated by [PERSON] [33] in 1967. With this, several researchers in computer science have sought to optimize the cooling in different types of hardware and technologies, e.g., processors and motherboards [34; 35; 36; 37; 38; 39; 40]. However, to the best of our knowledge, the studies on data center environments have provided efforts in solutions that deal with the modernization of servers, policies of optimization, or insertion of intelligent central control software. In contrast to previous studies, this article aims to investigate the following questions:  
1. Is it possible to achieve better energy efficiency in data centers just by changing the equipment's layout and taking advantage of legacy resources? 2. How to maintain the sustainable consumption of physical and energy resources in the data center despite the growing demand for processing and storage? 3. What know-how has been learned in the face of the challenges of implementing a data center in the context of tropical climate? In order to meet the research questions above, the following methodologies were explored to achieve energy efficiency and decrease the temperature of servers and consequently all environments: (i) cold air corridor confinement technique; (ii) adjusting the position of the data centers; and (iii) downflow air insufflation (cold air circulates under the raised floor) aided by grilles with high airflow directional control. The results demonstrate a significant reduction of 46% of the temperature inside the data center, reducing from 25 to 14 \({}^{\circ}\)C on average, only using legacy CRACs (Computer Room Air Conditioning) and maintaining good cooling performance, with a high index of cooling. Availability and uninterrupted security, including 36 new pieces of network equipment (routers and switches), 44 new servers, and 346 previously existing ones. Paper Outline: This work is organized as follows: Section 2 discusses the related works; Section 3 presents the data center improvements implemented; Section 4 shows and discusses the results, and finally Section 5 presents the conclusions.