Heating, Ventilation and Air- Conditioning (HVAC)

Part 2:

HVAC systems and components

Good Manufacturing Practice

Section 7

1

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

2

HVAC

General

Design of HVAC is dependent on required degree of air cleanliness

Suitable components should be selected including:

fans, driers, filters, ducts, grilles, etc. 7.

3

+

Production Room

Exhaust air treatment

Central air handling unit

Terminal air treatmentat production room level

Fresh air treatment (make-up air)

HVAC Main subsystems

4

HVACComponents

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 – 7.1.7

5

HVACComponents

Components in HVAC may include, depending on need:

Snow eliminators Dust eliminators Moisture eliminators Precooling coils Alarm systems, grilles/diffusers, etc.

7.1.1 – 7.1.7

6

FilterSilencer

Terminal filter

Weather louvre Control damper

FanFlow rate controller

Humidifier

Heating coil

Cooling coil with droplet

separator

Production Room

Overview components

+

Prefilter

Exhaust Air Grille

Heater

Secondary Filter

Recirculated air

HVAC

7

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

8

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

9

CONTROL 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

10

HUMIDIFIER SILENCER HEATING AND COOLING UNITS

HVAC

11

FILTER CLASSESDust filters

Standard Aerosol

FineCoarse ULPAHEPA

10 µ m > Dp > 1 µ mDp > 10 µ m Dp < 1 µ m

F5 - F9G1 - G4 U 14- 17H 11 - 13

EN 1822 StandardEN 779 Standard

HVAC

12

Primary panel filter

Secondary filter

HEPA or tertiary filter

HVAC

13

Average EfficiencyIntegral Value

Peak ArrestanceLocal Value

Retention in%

Penetration Efficiency Penetration

F9 85 0.15

H11 95 0.05

H12 99.5 5x10-3 97.5 25x10-3

H13 99.95 5x10-4 99.75 25x10-4

U14 99.995 5x10-5 99.975 25x10-5

Classification of filters according to their efficiency

HVAC

Positioning of filters (1)

Filter in terminal position AHU mounted final filter

Production Room

+

Production Room

HEPA Filter

HEPA Filter

HVAC

15

Prefilter

AHU

Main filter

1 2 3

Low level exhausts

Ceiling exhausts

Positioning of filters (2)

HVAC

16

AHUPrefilter

Final filter

21

Positioning of filters (3)

HVAC

17

SWIRL TYPE AIR DIFFUSORS WITH TERMINAL FILTERS

1 Filter2 Tightening frame3 Register outlet4 Screw fixation for register

1

2

3

4

HVAC

18

Low induction swirl diffusor(preferred)

High induction office type diffusor

(avoid)

HVAC

19

REGULATION OF ROOM PRESSURE – PRESSURE DIFFERENTIALS CONCEPT

Room pressure gauges

Room pressure indication panel

HVAC

20

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

21

HVACIn the next slidesConsider different air types, e.g.: Supply air

Return air (recirculated air)

Fresh air (make-up air)

Exhaust air

And: Concepts of air delivery to production areas: Recirculation systems

Full fresh-air systems

22

+

Production Room

Exhaust air

Return air(recirculated)

Fresh air(make-up air)

Supply air

Air types

HVAC

23

HVACRecirculation systems

There should be no risk of contamination and cross-contamination when air is recirculated

Normally, HEPA filters (EN1822 H13) needed in supply air stream

Not required in single product facility with no risk of cross-contamination

Not required where no dust generation (e.g. secondary packaging)

HEPA filters placed in AHU or terminally Dust from highly toxic processes should not be

recirculated 7.2.1 – 7.2.6

24

Ventilation with recirculated air + make-up air

Central Air-Handling Unit

Return air

Exhaust Unit

HVAC

25

HVAC

26

HVACFull fresh-air systems

100% fresh air - normally where toxic products are processed, and recirculation not recommended

No contamination from fresh air – sufficient filtration needed

Degree of filtration on exhaust dependent on exhaust air contaminants and environment regulations

Energy-recovery wheels Should not be source of contamination Relative pressure between supply and exhaust air

7.3.1 – 7.3.3

27

Ventilation with 100% fresh air (no air recirculation)

W

Washer (optional)

Central Air-Handling Unit

Production Rooms

Exhaust Unit

HVAC

28

HVAC

29

FINISH PART 230