hvac | slide 1 of 28 2013 heating, ventilation and air- conditioning (hvac) part 3: hvac systems and...

HVAC | Slide 1 of 28 2013

Heating, Ventilation and Air-

Conditioning (HVAC)

Part 3:

HVAC systems and components

Supplementary Training Modules on Good Manufacturing Practice

Section 7

WHO Technical Report Series, No. 961, 2011. Annex 5


Objectives

In the following slides, we will study the components of air- handling systems in order to:

1. Become familiar with the components

2. Know their functions

3. Become aware of possible problems

HVAC


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Production Room

Exhaust air treatment

Central air handling unit

Terminal air treatmentat production room level

Fresh air treatment (make-up air)

HVAC Main subsystems


HVACHVAC

Components

Components in HVAC may include, depending on need: Filters Fans

– no fan failure; including supply air fans, return air fans, exhaust air fan, dust extract system fans

Driers– Drying of air with chemical driers, e.g. rotating desiccant

wheel Frost coils for preheating air 7.1.1 – 7.1.6


HVACHVAC

General

Pharmaceutical products should be manufactured in areas of appropriate cleanliness

Prevent contamination and cross-contamination

Design of HVAC dependent on various factors e.g.– Outside air quality– Recirculation of air (or not)– Products and range of products

Risk assessment to determine clean room conditions. 7.1.1


HVACHVAC

General

Two basic concepts of air delivery– a re-circulation system, and – a full fresh air system (100% outside air supply).

Recirculation – determine the amount of fresh air based on criteria:

– to compensate for leakage and loss– to comply with national building regulations; and – for odour control.

7.1.2


HVACHVAC

General

Validated automated monitoring systems (e.g. Building management systems (BMS), building automation system (BAS) or system control and data acquisition (SCADA) system) - capable of indicating any out-of-specification condition without delay e.g. by means of an alarm

– Also helps with preventive maintenance and trend logging– Critical alarms easily identifiable, visible and/or audible

Fan interlock failure matrix

Fan failures can cause a system imbalance, resulting in a pressure cascade malfunction with a resultant airflow reversal.

7.1.3 – 7.1.6.


HVACHVAC

Air distribution

Positioning of supply and extract grilles to provide effective room flushing.

Low-level return or exhaust air grilles preferred.

If not possible, a higher air change rate may be needed to achieve a specified clean area condition, e.g. where ceiling return air grilles are used.

There may be alternative locations for return air7.2.1 – 7.2.2


HVACHVAC


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Production Room

Exhaust air

Return air(recirculated)

Fresh air(make-up air)

Supply air

Air types

HVAC


HVACHVAC

Recirculation systems

Increased risk of contamination and cross-contamination.

Need HEPA filters (EN1822 classification of H13)

HEPA filters may not be required:– a single product facility and there is evidence that cross-contamination would

not be possible.– No dust generated e.g. secondary packing

HEPA filters installed in the air-handling unit or terminally placed– If terminally mounted - not with flexible ducting

If highly toxic processes – never recirculate7.3.1 – 7.3.6


Ventilation with recirculated air + make-up air

Central Air-Handling Unit

Return air

Exhaust Unit

HVAC


HVACHVAC

Full fresh-air systems

100% fresh air normally used in a facility dealing with toxic products or solvents, where recirculation of air with contaminants should be avoided

Degree of filtration of the exhaust air depends on the exhaust air contaminants and local environmental regulations

HEPA filters in the exhaust system normally when handling hazardous materials

7.4


HVACHVAC


Ventilation with 100% fresh air (no air recirculation)

W

Washer (optional)

Central Air-Handling Unit

Production Rooms

Exhaust Unit

HVAC


HVACHVAC

Energy-recovery wheels

Risk assessment to determine cross-contamination risks

Should not become a source of possible contamination

Alternatives include crossover plate heat exchangers and water-coil heat exchangers

Prevent air leakage between the supply air and exhaust air– exhaust air system operates at a lower pressure than the supply system.

7.4.2 – 7.4.3.


HVACHVAC


HVACHVAC

Components

Components in HVAC may include, depending on need:

frost coils to preheat the air

reheaters for humidity control, moisture eliminators

automatic air volume control devices

sound attenuators

snow eliminators, dust eliminators,

fresh air precooling coils7.5.3


FilterSilencer

Terminal filter

Weather louvre Control damper

FanFlow rate controller

Humidifier

Heating coil

Cooling coil with droplet

separator

Production Room

Overview components

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Prefilter

Exhaust Air Grille

Heater

Secondary Filter

Recirculated air

HVAC


Weather louvre

Silencer

Flow rate controller

Control damper

To prevent insects, leaves, dirt and rain from entering

To reduce noise caused by air circulation

Automated adjustment of volume of air (night and day, pressure control)

Fixed adjustment of volume of air

Components (1)

HVAC


Heating unit

Cooling unit/ dehumidifier

Humidifier

Filters

Ducts

To heat the air to the proper temperature

To cool the air to the required temperature or to remove moisture from the air

To bring the air to the proper humidity, if too low

To eliminate particles of predetermined dimensions and/or microorganisms

To transport the air

Components (2)

HVAC


Control damper for airflowControl damper for airflow

De-humidificationFilter Pressure

Gauges

AHU with fan Variable Speed Controller

Humid room air

Air heater

Regeneration air

Humid room airAdsorber wheel Dry air

Air-handling unit

HVAC


Humidifier Silencer Heating and cooling units

Humidifier Silencer Heating and cooling units

HVAC


Primary panel filter

Secondary filter

HEPA or tertiary filter

HVAC


Swirl Type air diffusors with terminal filters

Swirl Type air diffusors with terminal filters1 Filter

2 Tightening frame3 Register outlet4 Screw fixation for register

1

2

3

4

HVAC


Flow rate controller Control damper

Humidifier

Cooling battery

Filters

Ducts

Blocked Poorly adjusted, bad pressure

differential system Bad water/steam quality/ poor drainage No elimination of condensed water/

poor drainage Incorrect retention rate/damaged/badly

installed Inappropriate material/internal insulator

leaking

Problems with components

HVAC

hvac | slide 1 of 28 2013 heating, ventilation and air- conditioning (hvac) part 3: hvac systems and...

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