hygienic a/c system and standards · hygiene requirements for ventilation and air-conditioning...

Hygienic A/C System and StandardsIntroduction

Brief introduction to Hygienic Standards followed in HVAC

Hygienic Air Handling Unit Qualification

Organised by

Introduction1

Hospital Pharmaceutical Laboratories Food IndustryElectronic Facilities

Where Hygienic Air System Is Required ?

Hygienic Ventilation & Air-Conditioning Systems / Units Objective :

Maintain comfort conditioning

Maintaining air quality

Filtrate the supplied air to remove the particles and microorganisms,

Reduce airborne infections

Not a source of bacterial and fungal growth

Control Odor

Introduction

Biological Agents

2

Fungi, growing in ventilation systems, may contaminate indoor environments and

cause a variety of problems such as

Lung infections,

Allergic reactions in low immune people

Respiratory irritation in non-allergic people.

Sick Building Syndrome (SBS)

Inhalation of fungal spores by low immune people can have fatal consequences.

Some environmental bacteria can grow in ventilation systems and can cause

nosocomial problem.

Health Problems Due To Biological Agents

Includes bacteria, viruses, fungi (including yeasts and moulds) and internal human parasites

(endoparasites).

The majority of these agents are harmless however some may have potential to cause ill

health.

Introduction

How An Air-Conditioning System Will Become A Source Of Biological Agents

3

Air Handling unit may become a source of biological hazards due to its

Improper design

Cooling coils, drains pans are likely locations for fungal growth, especially when there is standing water. Access sections are not

provided, in appropriate components location within the unit.

Inappropriate material selection.

The components with porous structures such as gaskets, rubber or plastic parts are also a source of bacterial or fungal accumulation

and its growth.

Inadequate maintenance

Hygienic Standards followed in HVACVDI 6022 Part 1, DIN 1946 Part 4, EN 1886, EN 13053

Standards4

VDI 6022 : Ventilation and indoor air quality - Part 1 - Hygiene requirements for ventilation and air-

conditioning systems and units

DIN 1946-4 : Ventilation and air conditioning - Part 4 - Ventilation in buildings and rooms of health care

EN1886 : Ventilation for buildings - Air Handling Units – Mechanical performance

EN13053 : Ventilation for buildings - Air Handling Units – Rating and performance for unit’s

components and sections

Standard - VDI 6022

Hygiene requirements for ventilation and air-conditioning systems and units

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VDI

German association of engineers (Verein Deutscher Ingenieure).

VDI 6022

Is a set of technical guidelines to ensure good hygiene in ventilation systems.

The guideline deals with hygiene in HVAC systems with the objective of preventing negative effects on

room air.

It lists the integrated hygiene requirements regarding constructional, technical and organizational impacts

on the planning, construction, operation and maintenance of HVAC systems.

Additionally, it serves as a basis for the testing during a hygiene inspection.

These requirements primarily serve to protect the health of individuals.

Standard - VDI 6022

Hygiene requirements for ventilation and air-conditioning systems and units

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Application

All rooms or occupied areas in rooms which are intended for use by person on more than 30 days per year

or more than two hours per day on a regular basis.

VDI 6022 Part 1 applies to all ventilating and air conditioning system and air handling units as well as

central or decentralized components which influence the quality of supplied air.

VDI certification

No pathogenic spores or hazardous substances throughout the entire lifetime of the system.

Better indoor climate, for optimum well-being and performance, while avoiding sick days and asthma and

allergy problems.

Market’s strictest hygiene requirements are met.

VDI certified materials ensure that they cannot provide a growth base for bacteria or fungi.

Standard - DIN 1946-4

Ventilation in buildings and rooms of health care

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DIN

German Institute for Standardization (Deutsches Institut für Normung e.V. )

DIN 1946

This standard has been prepared by the Standards Committee for Heating and Ventilation taking

into consideration current technical rules in Germany that are relevant to hygiene, namely VDI 6022

Part 1, ÖNORM H 6020 and SWKI 99-3.

Application

This standard applies to the planning, construction, acceptance testing and operation (including

maintenance) of ventilation and air-conditioning (VAC) systems in buildings and rooms for health

care, in which medical examinations, treatments and interventions are performed on persons, as

well as in rooms directly connected by doors or corridors

Standards - DIN 1946-4

General Requirements For Ventilations And Air Conditioning Components As Per DIN 1946-4

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Location of Components

Readily Accessible for Cleaning

Surfaces and Materials within the air flow

Surfaces do not emit harmful substances and do not provide a nutrient medium for

microorganisms

Cleaning Management Plan

All components shall be delivered in a clean condition and be protected against contamination

or damage during the course of construction

Labelling

All system components shall be visibly and permanently labelled or marked



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Ductwork



10

Sheet Metal

Internal surfaces shall be abrasion-proof, corrosion-resistant and smooth (e.g. of sendzimir

galvanized sheet steel). To avoid injuries, there shall be no sharp edges.

All Metal parts coming in contact with air flow is either SS or powder coated GI

All gaskets, plastic parts, Rubber Parts and Sealants coming contact with air is not a source

of bacteria and Fungal Growth. All Such parts have test report according to ISO 846 and

according to VDI 6022 Standards.

No materials cause threat to human health. No Material which facilitate the growth of

harmful micro organisms



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Damper

Damper Blade should be Aero foil design

Motorized damper with parallel or opposed blades and should close automatically during any power

failure to avoid any entrance of Dirt or Dust particles inside the unit

Damper Location Internal For Outdoor Units and F/A units. Damper Location External For Indoor Units

Dampers-Should Be Air Tight . Meet the requirements of class 4 according to DIN EN 1751.



12

Filter

Filter material to be Coated with biostatic preservative to inhibit the growth of fungi and bacteria

The filter area shall be ≥ 10 m2 per m2 of the cross-sectional area of the unit.

Filter Efficiency (DIN 1946 part 4: Section 6.5.7.3 )

EN 779 for Pre & Fine Filter

EN 1822 for HEPA filter)

Filtration stages (DIN 1946 part 4: Section 6.5.7.4)

For class I rooms, a three-stage supply air filtration is required,

1st filtration stage: at least class F5 filters, class F7 filters are recommended;

2nd filtration stage: class F9 filters;

3rd filtration stage: class H13 HEPA filters.

For class II rooms, a two-stage filtration system (without HEPA filters) is sufficient.

Accessories (DIN 1946 part 4: Section 6.5.7.4)

Hinged access door with Quick disconnect Latches

Manometer across filters

Inspection window

Bulk head light



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Filter arrangement

Filter rack are designed for filter removal from the dirty side (DIN 1946 part 4: Section 6.5.7.1)

Filter chambers in the 1st and 2nd filtration stages shall be designed so that no dust reaches the clean air side when changing the filter.

Springs and clamps used for filter fastening and sealing shall not act against the air flow by themselves (DIN 1946 part 4: Section 6.5.7.1)

The first filtration stage are located within the air handling unit, near the outdoor air suction opening and have a minimum efficiency of F5 as per EN 779.

(DIN 1946 part 4: Section 6.5.7.4 & Section 6.5.7.5). Additional coarse filters G1 to G4 are permissible.(DIN EN 13053: Section 6.9.2 )

The second filtration stage is the last component of the air handling unit, i.e. it shall be installed on the pressure side downstream of the last air handling

component. (DIN 1946 part 4: Section 6.5.7.5)

Coolers and humidifiers are not installed immediately upstream of any of the filters. (DIN 1946 part 4: Section 6.5.7.5)

1 2 3 387364 3 95

1. Mixing Box w/ motorized dampers

2. F5 filter w/ manometer, inspection window and light

3. Access section

4. Cooling coil w/ drain pan

5. Moisture Eliminator (if needed)

6. Humidifier w/ drain pan (if needed)

7. Direct Driven Plug Fan

8. Sound Attenuator (if needed)

9. F9 filter w/ manometer, inspection window and light



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Fan

Direct driven fans (plug fans) to be used (as per DIN 1946-4 and VDI 6022 part 1: Section 4.3.14 Fan)

The entire fan unit, including the impeller and the base frame of sheet steel and sectional steel, are

protected against corrosion (DIN 1946 part 4: Section 6.5.10: Fans)

The fans are easily accessible to operating and maintenance personnel (DIN 1946 part 4: Section

6.5.10: Fans & VDI 6022 part 1: Section 4.3.14 Fan)

Supply air fans shall be located between the 1st and 2nd filtration stages to exclude any precipitation

of water inside the fan.

Accessories

Push Fit Gasket

Bulk head light

Stainless Steel Conduit

Inspection Window

Internal handles for access doors

Flow measuring device



15

Drain Pan

Drain pan is mandatory to provide for Cooling coils, humidifiers and heat recovery sections.(DIN 1946

part 4: Section 6.5.5 )

Stainless steel, double skin, insulated and 3-way sloped condensate drain pan with drainage

connection (DIN 1946 part 4: Section 6.5.5)

After filling the drain pan with 5 liters of water per m² of drain pan area, more than 95 % of the filled

water has been drained off over a period of 10 min. (DIN 1946 part 4: Section 6.5.5)

Removable drain pan shall be provided on request

Moisture Eliminator

Eliminators are installed to ensure that droplets of water from humidifiers or air coolers do not enter

downstream components or system parts installed (DIN 1946 part 4: Section 6.5.8.3)

Eliminator can be removed for cleaning purposes from the casing via service doors (DIN EN 13053:

Section 6.4.4 )

Eliminator Frame : Stainless steel

Eliminator Blade : Stainless steel or PVC with ISO 846 test report



16

Maintenance Access

Unit interior should be smooth, with out any projecting screws and with adequate space for cleaning

Components should be easily accessible/removable for maintenance

Standard – EN 1886

Ventilation For Buildings - Air Handling Units – Mechanical Performance

17

This standard specifies test methods, test requirements and classifications for air handling units which are supplying and/or extracting air, via

ductwork, for ventilating/conditioning a part or the whole of the building.


Ventilation For Buildings - Air Handling Units – Mechanical Performance

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Ventilation For Buildings - Air Handling Units – Rating And Performance For Unit’s Components And Sections

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EN 13053 Standard is a part of a series of standards for air handling units used for ventilation and air conditioning of buildings for human occupancy.

It considers the ratings and the performance of air handling units as a whole, the requirements and performance of specific components and sections of

air handling units including hygiene requirements.

Applicable to standardised designs, Custom-design units, Completely prefabricated units, Built up on site

It is supported by the standard for mechanical performance, EN 1886

The ratings and the performance of whole air handling includes :

Air flow - Available static pressure - power input,

Octave band in-duct sound power level,

Airborne sound power level,

Heating capacity & Cooling capacity,

Pressure loss on water side

Hygienic Air Handling Unit

Hygienic AHU Qualification

20

AHU ComponentHygienic Standard requirement

VDI 6022/DIN EN 1946

AHU Frame Material & Panel Thickness -

AHU Panel Outer Skin Powder Coated

AHU Panel Inner Skin SS 304 or Anti-microbial coated AL/GSS

Internal Guideways & Racks (Coils, Filters, etc.,) SS 304 or Anti-microbial coated AL/GSS

Gaskets & Sealants VDI 6022 Certified & ISO 846 Tested

Access Doors With Stainless Steel internal Handles

Internal Surface Finish Smooth, without any cavities and projected Screws

Accessories Light, Inspection window, Manometers, Air flow switch

Damper Motorized Aluminium aerofoil blades w/ leakage class 4

Filter at the inlet of the AHU F5 filter

Filter at the outlet of the AHU F9 filter, HEPA filter (if needed)

Filter Removal Dirty Side

Cooling Coil & Coating Requirement -

Drain Pan For Coil, Humidifier and Heat Recovery Device

Drain Pan Material Stainless Steel 304 3-Way Sloped

Eliminator Frame Stainless Steel 304 or Powder Coated

Eliminator Blade Stainless Steel 304 or PVC ISO 846 Certified

Supply Fan Plug Fans

Maintenance Access Available for each sections

Kamalakhya DebCountry Manager – Gulf, Applied Products

SKM Air Conditioning LLC

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hygienic a/c system and standards · hygiene requirements for ventilation and air-conditioning...

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