HVAC&R systems ensure comfort and well-being for people in closed environmentsLeitura de 5min
Brazilian Association of Technical Standards offers the necessary guidelines for the development of an efficient air conditioning project.
Every day, the average person breaths in around 10,000 liters of air and spends 85% of his or her time in closed environments such as offices, banks, shopping centers, hospitals and fitness centers. These figures from the Brazilian Association for Heating, Ventilation, Air Conditioning and Refrigeration (Abrava) underscore the importance of HVAC&R, a matter that is not often addressed but is significant to ensuring the comfort and well-being of people who spend time in such environments.
According to Edison Greca, manager of the Project Management and Development (PDS) area at JLL, the norms drawn up by the Brazilian National Standards Organization (ABNT) provide the necessary guidelines to develop an efficient HVAC&R project – something that goes far beyond a simple air-conditioning system. “It involves two questions: treatment of the air, and renewing the air,” said Greca, an engineer. He explained that the latter objective implies paying attention to the rate at which air is changed in a closed space. “This means having an external air intake, ducts and ventilation equipment that can withdraw the spent air from the area.”
To calculate the volume of air that must be recycled in a specific space – which will determine the installation of ducts and ventilators – it’s necessary to know the exact dimensions of the environment, how many people it will hold, and if volatile elements are present within the materials used in the area, such as the carpets, the paint on the walls, and so on. These details are processed according to formulas and graphs, or even by means of specialized software, to generate the parameters and dimensions for the equipment and ducting needed in each environment.
In a large parking area, for example, there is a build-up of carbon monoxide that requires constant renewal of the air. This is done via ducts that link with external areas, together with systems for ventilation and filtering. All this requires careful analysis,” Greca said.
He mentioned another factor that is important to consider when evaluating closed environments: the thermal load. “People emit two types of heat: sensible heat, which is emitted by the body; and latent heat, generated by breathing and perspiration. These are variables that make a difference, depending on the profile of the development. If we compare the thermal load in a movie theater and a gym, for example, we will get totally different results. These data must be calculated and taken into consideration,” he said.
An optimal HVAC&R system, Greca explained, will generate lower demand for air-conditioning equipment, which in turn is a measure of sustainability.
The better the integration between the architectural design and the design of the HVAC&R system, the more likely it is that this system will be good. After all, there are various factors that can contribute to heat retention or dissipation in an area, including the type of roof, the façade, the wall covering and the color of the outer walls,” Greca said.
When acting as a consultant, he said, JLL will evaluate the condition of all these systems. Then, if the client plans installing or upgrading an HVAC&R system in his property, JLL will bring in specialized partners.