The document presents a designed HVAC system for a COVID-19 intensive care unit. It discusses the importance of HVAC systems in controlling the spread of airborne diseases like COVID-19. The designed system includes components like mixing chambers, filters, ultraviolet light emitters, humidifiers, and HEPA filters to purify air and reduce virus transmission. Benefits of the system include using UV light to reduce microorganisms and controlling indoor air quality. Maintaining the HVAC plant involves periodic filter replacement and equipment maintenance to ensure proper functioning.

1. A PRESENTATION
ON
THE HEATING, VENTILATING, AND AIR CONDITIONING (HVAC) SYSTEM OF COVID’19
INTENSIVE CARE UNIT.
PRESENTED BY
GROUP 7
DEPARTMENT OF BIOMEDICAL TECHNOLOGY,
FEDERAL UNIIVERSITY OF TECHNOLOGY, AKURE.
LECTURER IN CHARGE
MRS. BENSON FUNMI
18TH MARCH, 2021.

2. GPOUP MEMBERS
S/N NAME MATRIC NUMBER
1. AMAECHI MARTINS .E. BIM/15/3167
2. ODUNSI ADEWALE TIMOTHY BIM/15/3195
3. ENIOLA OJO BIM/15/

3. INTRODUCTION
 Heating, ventilation and air-conditioning (HVAC) has a pivotal role in determining infection
rates in the intensive care unit (ICU), apart from its primary purpose of providing
comfortable living and safe environment for the patients, ICU staff and visitors. Essential
functions of HVAC system includes heating (adding heat to raise or maintain temperature),
cooling (removing heat to lower or maintain temperature), humidifying (adding water
vapour), dehumidifying (removing water vapour) in order to maintain the moisture content
of the air, filtering (removing dust particles, biological contaminants like bacteria, viruses and
fungi), ventilating (air change rates between outdoor) and air distribution (velocity, flow
pattern, direction of movement and distribution patterns.

4. HVAC SYSTEM IN COVID’19 (AS A CASE STUDY)
 Generally research proved that Airborne diseases have been linked to poorly functioning
HVAC system that is improper function of temperature control, humidity control, air
distribution and filtration of HVAC systems.
 The recent severe acute respiratory distress syndrome (SARS) outbreaks nationwide
coronavirus (COVID’19) which lead to epidemics, indicated that there exists a correlation
between building factors related to air circulation and rate of occurrence of infections. The
functional aspects of HVAC system like relative humidity and temperature have a significant
correlation with nosocomial infection rates especially in ICUs and geriatric population.

5. HVAC SYSTEM IN COVID’19 (AS A CASE STUDY) CONTD.,
 There are various factors which play a role in the transmission of airborne diseases such as
particle characteristics: size (droplet ≥ 5 μm; airborne pathogen ≤ 5 μm), type, life span,
distance travelled and the surrounding environment along with architectural design, apart
from host risk factors.

6. IMPORTANCE OF HVAC SYSTEM IN COVID’19 (AS A CASE STUDY)
 Once a COVID patient enter ICU, air handling systems (HVAC) control their spread, aid in
their removal from the system in both droplet-borne form and airborne diseases. This is
achieved either by ‘diluting’ the pathogen (dilution ventilation) or by removing the pathogen
(exhaust ventilation). An improperly maintained HVAC system can be a continuing source of
contamination, an example of which is the growth of moulds and other fungi in damp and
wet surfaces such as cooling coils, humidifiers, condensate pans and filters. Poorly designed
and maintained HVAC systems in the ICU can lead to ‘sick building syndrome’ (SBS),
characterized by suffocation which can lead to decreased staff performance in addition to
various hospital-acquired infections and occupational hazards and increasing the spread
(contamination) of Covid virus.

7. A DESIGNED HVAC SYSTEM FOR COVID’19 INTENSIVE CARE UNIT.
An outdoor air intake and air exhaust ducts
and controls HVAC system was designed to
suit COVID’19 Intensive care unit.

8. HVAC SYSTEM FOR COVID’19 FOR INTENSIVE CARE UNIT.

9. HVAC SYSTEM FOR COVID’19 FOR INTENSIVE CARE UNIT. CONTD.,

10. COMPONENTS FOR THE DESIGNED HVAC FOR COVID’19 IN
INTENSIVE CARE UNIT
1. Relief Air Damper : Dampers are used to cut off central air-conditioning to unused rooms
and for regulating the air supply room by-room.
2. Damper :
3. Mixing Chamber : This mix the natural air with returned air preparing the air for filtering.
4. Pre Filter : The first layer of the filter acting as the roughing filter removing larger particle
matter and many microbes.
5. Fine Filter: To purify the air, removing smaller size particles in the air.
6. Heating Coil: This generate the heat for heat exchange transfer (energy).

11. COMPONENTS FOR THE DESIGNED HVAC FOR COVID’19 IN
INTENSIVE CARE UNIT CONTD.,
7. Ultraviolet Light Emitters: This is used as a germicidal irradiation agent to reduce the virulence of
the micro organisms.
8. Cooling coil with drain: The latent heat is transferred by moisturize in the air to the coil via the
process of condensing on the surface of the cooling coil.
9. Humidifier: To add water vapour to the air.
10. HEPA Filter: High Efficiency Particulate Air, a filter that is designated to filters or trap 99.97% of
particles that are 0.3 microns.
11. Blower / Fan: Supply fans provide energy to drive the air through the system. (using centrifugal
force)
12. Blower / Fan:

12. COMPONENTS FOR THE DESIGNED HVAC FOR COVID’19 IN
INTENSIVE CARE UNITCONTD.,
13. Supply Venturi Air Valve: This is the inlet switch valve of the ducts pipeline.
14. Thermostat Sensor: To pick the temperature degree of the room.
15. Exhaust Venturi Air Valve: This is the outlet switch valve of the ducts pipeline.

13. BENEFITS
 The Presence of Ultraviolet (UV) light emitters or ultraviolet germicidal irradiation (UVGI):
Ultraviolet light is used as a germicidal irradiation (UVGI) agent to reduce the virulence of the
microorganisms. This is usually used in the exhaust air ducts of HVAC system to supplement
HEPA filtration.
 Ability to control Indoor Air Quality IAQ by assessing temperature, carbon dioxide (CO2)
concentration, humidity and airflow rates and adjusting according to the work environment.
 Air distribution systems: It can be of full fresh air or single-pass system (displacement
ventilation) or the traditional re-circulation type (mixing ventilation) systems , where
recirculated air requires adequate filtration. Displacement ventilation has advantages like
better acoustics and less noise, low pressure drops, and low energy consumption, requires a
lower grade

14. BENEFITS
 Air distribution systems It can be of full fresh air or single-pass system (displacement
ventilation) or the traditional re-circulation type (mixing ventilation) systems where
recirculated air requires adequate filtration. Displacement ventilation has advantages like
better acoustics and less noise, low pressure drops, and low energy consumption, requires a
lower grade of filtration and has high ventilator efficiency as 100% fresh air is delivered to the
occupants
 Ability to close dampers (Dampers are used to cut off central air-conditioning to unused
rooms and for regulating the air supply room by-room). These can play a role as
economizers that can be placed at supply, relief and return components of HVAC system.

15. LIMITATIONS
 Cost of Projects
 Cost of Maintenance: Maintenance of the HVAC plant The interaction between fans and filters
for the maintenance of pressure and flow directions in various places causes unavoidable
wear and tear of the plant. This process requires periodic air vent monitoring, odour
monitoring, and replacement of filters as per the manufacturer’s recommendations along with
‘filter forensics’ which include recovery of microbiota from residual HVAC filters . Other than
filter testing, annual maintenance of fans, bearings and belts, fixing leaks in the cabinet and
the supply duct along with performance monitoring of chilled water distribution systems (heat
exchangers) are all necessary.

16. CONCLUSION
 Knowledge and understanding of proper functioning of HVAC systems is crucial for critical
care physicians, a a proper HVAC System will reduce the spread of COVID’19 and other
airborne infections. With the continuous advancement of technology, there exists an urge
for clear and consistent universal standards for HVAC system with a specific mention on the
type of ICU like general, neonatal, and burns, which should be updated and incorporated
into existing infection control practice guidelines.

17. THANK YOU FOR LISTENING