The Bosa Hospital, in Colombia, is a project under construction that will be LEED Silver Category. Air conditioning was essential to achieve this environmental seal.
by ACR Latinoamerica
The health sector and especially that of hospitals has been one of the great challenges for specialized engineers in our industry. Their high levels of demand and the importance of monitoring the standards, make these projects attract attention.
Precisely, the Bosa Hospital project, located in a town southwest of the city of Bogotá, is currently under construction. The construction of this space began in November 2021 and is estimated to enter into operation by the end of 2023.
The project is a public hospital of 30,000 m2 with more than 200 beds, in a highly complex hospital building that will have seven operating rooms, intensive care unit with isolated rooms, sterilization center, medicine center and a basic care building and specialized clinics (CAPS building).
According to the Spanish construction firm, Grupo Ortiz, the project will be part of the Southwest Subnetwork impacting 4 locations – Kennedy, Fontibón, Puente Aranda and Bosa, and will benefit more than 400,000 people.
The Specialized Hospital Medical Unit of Bosa will be designed to offer outpatient services -the complex will have an integrated Primary Health Care Center type 2- and medium and high complexity hospitals and will contribute to the public network 215 beds that will be distributed as follows: 135 for Internal Medicine, 60 in surgical services, 12 for adult intensive care and 8 for adult intermediate care.
This will be the first social infrastructure carried out in Colombia under the Public-Private Partnership (PPP) scheme. It will also become the first public hospital to be LEED (Leadership in Energy & Environmental Design) certified in the "Silver" category.
The air conditioning system
The air conditioning consultant, Eng. Juan Orozco, from the company INGO HVAC, shared the details of the project focused on the area of air conditioning.
The engineer commented that a cold water plant of 140 TR was implemented consisting of 2 water chillers of 70 TR each, type scroll of condensation by air, of high efficiency. Each chiller handles up to 65% of the maximum block load to allow the cooling of the building to continue even in case of failure of a chiller, taking advantage of the high load diversity of the building.
It is important to highlight that the system is coupled to a water distribution network of the variable primary type with vertical type pumps "in line sensorless" and PICCV 2-way valves in handlers. This system attends the critical spaces of the hospital tower: medicines, imaging, morgue, emergency, clinical laboratory, operating rooms, ICU, isolated, sterilization center, preparation and recovery rooms. The generation of hot water for space heating and for air reheating in humidity control is obtained from the project's boilers, in a circuit dedicated to the air conditioning system.
For the calculations and designs, the regulatory requirements of this type of spaces were taken into account, especially with regard to air quality, according to ASHRAE 170 and 62.1 standards; In addition, all systems were selected to exceed ASHRAE 90.1, so that the air conditioning and mechanical ventilation system achieves the necessary points for LEED Silver accreditation.
Special attention was paid to the filtration of spaces, specifying units with high filtration, especially HEPA in operating rooms, ICUs and isolated units. Likewise, the positive or negative pressurization of each space, supported by a robust automation and control solution, with variable volume boxes in operating rooms and Venturi valves in isolated rooms, which allow precise flow control and increase or decrease the speed of operating machine motors that have VFD. The control system has enthalpy sensors, so when the outdoor conditions of Bogotá allow it, you could have "free cooling" with 100% outside air.
Natural and mechanical ventilation for other spaces
In other spaces of the hospital tower, such as hospitalization floors, external waiting rooms, administrative spaces, common rest and socialization areas, and the entire CAPS building have 100% outdoor air mechanical ventilation systems, supported with heating in hospitalization rooms and other spaces that may require it.
Mr. Orozco stressed that all ventilation systems have double filtration stage up to MERV 15, and where required, support is specified with air handling units by UVC lamps and / or ionization that does not generate ozone.
Likewise, all spaces have air quality sensors. For spaces such as external waiting rooms, common rest / recreation areas, hospitalization corridors, CAPS building, a bioclimatic strategy with natural ventilation was implemented, with mechanical ventilation support in several of the spaces that would only come into operation if air quality was not achieved (ventilation on demand). For natural ventilation, special care was taken not to affect critical spaces.
The rehabilitation pool area of the CAPS building has a conditioning / heating system with humidity control, special for this type of space.
Juan Orozco also stressed that all subsystems (chillers, pumps, handlers, ventilation units, extraction units, pool dehumidifier unit, stair pressurization fans) are integrated through the automation and control system, which has enthalpy, water and air temperature, CO2, air velocity and differential pressure sensors. By means of centrifugal pumps and PPR pipe for hot water, heating is available from the boilers of the project.
Another important aspect of the project was that it was carried out under the BIM (Building Information Modeling) methodology, which facilitated the coordination work between the different disciplines, however, the need to resize several sections of ducts was presented. "But it is encouraging that in public works there is already awareness about the importance of the BIM methodology and there is more and more maturity and development in its implementation," said Javier Reyes, from the construction company Grupo Ortiz.
Pending results, once the project is completed, the engineers are sure that an efficient and convenient system was achieved, in accordance with the requirements of the integrated health subnetwork southwest of Bogotá, especially the objective of being a safe hospital according to WHO guidelines, with sustainable and efficient design according to the parameters of LEED certification.
Project: Hospital de Bosa
Constructor: GRUPO ORTIZ of Spain, in contract modality Public-Private Partnership
Installer signature: AAIC
Manufacturers involved: YORK chillers and handlers, Spler & Palau ventilation system, Schneider Electric automation
Place covered with installation: Bosa Hospital Tower and CAPS Building (Priority Health Care Center)
Installation dates: Construction began in November 2021 and is expected to be completed by the end of 2023.