Indoor Air Quality is a major concern to businesses, building managers, tenants, and employees because it can impact the health, comfort, well being, and productivity of building occupants. Individuals spend up to 90% of their time indoors and many spend most of their working hours in an office environment. Air borne bacteria are 2-10 times higher indoor then outdoor.
Factors contributing to Indoor Air Pollution
Indoor air quality is not a simple, It is a constantly changing interaction of complex factors which affects the type, level, and importance of pollutants in indoor environments.
These factors include: sources of pollutants or odors; design, maintenance and operation of building ventilation systems; moisture and humidity; and occupant perceptions and susceptibilities. In addition, there are many other factors that affect comfort or perception of indoor air quality.
Pollutants in our indoor environment can increase the risk of illness. Most buildings do not have severe indoor air quality problems; even well-run buildings can sometimes experience episodes of poor indoor air quality.
Pollutants can be generated by outdoor or indoor sources, including building maintenance activities, pest control, housekeeping, renovation or remodeling, new furnishings or finishes, and building occupant activities.
There are numerous sources of airborne toxic pollutants in these indoor environments where outdoor air ventilation provides the only primary means to dilute pollutant concentrations. Volatile Organic Compounds (VOC's) are one class of indoor pollutants that may cause irritation to building occupants.
Research indicates that improvement in Indoor Air Quality (IAQ) :
• Increases productivity by 5-10 % & more.
• Reduces asthma by 8% - 25%.
• Reduces other respiratory illnesses by 23 % - 76 %.
Role of Ozone Generator in HVAC / AHU System in Bank
HVAC System in an Airports account for upto 60% of electricity consumption.
Major cost borne by the Users.
Major impurities in Indoor Air Environment are:
Volatile Organic Compound (VOC)
In Indoor Environment Toxic Gases are emitted from wide variety of sources:
• Building Materials • Cleaners, Plastics,
• Wood Products • Paints, Carpets,
• Polisher • Deodorants, etc
Volatile Organic Compound (VOC)
It adversely affect to:
Allergy, Asthma, Eye & Nasal irritation, Affect respiratory tracts, etc.
Carbon - di - oxide - Co2
In an indoor environment human being Exhale Carbon dioxide it cannot be reduced or oxidized.
It is not a toxic or carcinogen but a high level of CO2, causes:
• Headaches, Restlessness,
• Difficulty Breathing, Sweating,
• Tiredness, Increased Heart Rate,
• Elevated Blood Pressure, etc
Odor
Odour is a major Irritants & it is cause from various sources:
• Food Odour
• Body Odour
• Mold, Fungi & Microbes
• Cleaning Chemical Odour, etc
This is a residual odor & difficult to dilute from conventional method.
These are collectively known as "SICK BUILDING SYNDROME"
To address Sick Building Syndrome (SBS) the AHU systems take “Outdoor Air” to dilute Volatile Organic Compound (VOC) and reduce Carbon dioxide (CO2) within acceptable limits.
Conventionally Fresh Air is used to improve Indoor Air Quality (IAQ)
• Fresh air is not cheap!
• Hot and humid air needs to be cooled down to room temperature.
Hidden Cost of Fresh Air taken by Air Handling Unit in an HVAC System:
Load profile of fresh air
• 60% to cool moisture … wasted energy
• 28% to cool nitrogen …..wasted energy
• 12% to cool oxygen …..the only useful component in fresh air
Energy Consumption- 150 CFM of Fresh Air will require 1ton of cooling load. (Approximately
Position of ASHRAE on reducing fresh air intake:
“ASHRAE approves reduction in fresh air, if chemical contaminants in air are removed”.
We refer you to the following sections of ASHRAE62-99:
“Procedure for use of cleaned recirculated air: The amount of outdoor air may be reduced by recirculating air from which offending contaminants have been removed or converted to less objectionable forms. Formaldehyde, for example may be oxidized to water and carbon dioxide. The amount of outdoor air depends on the contaminants generated in the space, etc
ASHRAE Standards
• ASHRAE Ventilation code no. 62-1999.
• Minimum 15 CFM per person fresh air is required.
• Minimum of 30 CFM fresh air is required if smoking is permitted.
Chemtronics’ Solutions to minimize “Fresh Air Intake
How to reduce “Fresh Air”
• By using controlled injection of ozone.
• Oxidation of Volatile Organic Compound (VOC) is performed by ozone and not by oxygen of the fresh air.
• Ozone is more powerful oxidizing agent than oxygen.
• In the presence of a more powerful oxidant, less powerful oxidant does not have the chance to perform oxidation, until no more of the former is available.
• Oxygen of the fresh air is preserved and not spent in performing the task of oxidizing the Volatile Organic Compound (VOC), which is now transferred to ozone.
• Available oxygen is now used entirely to maintain Carbon-di-oxide.
• Intake of fresh air is reduced drastically. Thus fresh air requirement goes down to 5CFM or less per person.
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