Detailed presentation on design criteria for STP | OWC | Garbage Room | Solid waste | Kitchen Exhaust odour & pollutant destruction system. Extremely useful for MEP consultants, architects, kitchen consultant, real estate developers & exhaust ventilation contractors. In this presentation we have also provided link for mobile app to select the suitable model for odour & pollutant destruction.

1. Design Criteria [DC]
Exhaust Air Odor Control System
 STP
 OWC
 Garbage Collection Room
 Waste Segregation Room
 Washroom Odor Control
 Municipal Garbage Processing Plants
 Solid Waste Processing Plants
Note: Given design criteria are not universal. These are only applicable for “Chemtronics” “Capture & Treat” Technology.

2. Compound Formula Odor threshold
(ppb)
• Hydrogen sulphide H2S 0.4
• Carbon disulphide CS2 2.8
• Methane thiol CH3S 1.0
• Ethane thiol C2H5S 0.2
• Propane thiol C3H7S 0.5
• Dimethyl sulphide CH3-S-CH3 1.0
• Diethyl sulphide C2H5-S-C2H5 0.25
• Dimethyl disulphide CH3-S-S-CH3 0.3 – 10
• Dimethyl trisulphide CH3-S-S-S-CH3 -
Partial List of Exhaust Gases - Sulphur compounds

3. Compound Formula Odor threshold
(ppb)
• Ammonia NH3 37
• Methylamine CH3NH2 1 – 50
• Ethylamine CH2H5NH2 2,400
• Propylamine C3H7NH2 7
• Dimethylamine (CH3)2NH 20 – 80
• Trimethylamine (CH3)3-N 0.2
• Indol C8H6N 1.5
• Skatol C9H8N 0.002 – 1.0
• Fatty acids
• Vinegar acid CH3COOH 37
• Butter acid C2H5COOH 0.05 – 2.0
• Valerian acid C3H7COOH 4,600
Partial List of Exhaust Gases - Ammonia compounds

4. Partial List of Exhaust Gases – Aldehyde & Ketone Compounds
Compound Formula Odor threshold (ppb)
• Formaldehyde CH2O 37
• Acetaldehyde CH3CHO 0.005 – 2.0
• Acetone CH3-CO-CH3 4,600
• Butanone C2H5-CO-CH3 270

5. Oxidation Chemical Formula
• H2S + O3 → SO2 + H2O
• 2NH3 +4O3 → NH4NO3 +4O2 +H2O

6. 20 Points - Odor Control System Design
1. Capacity & treatment technology of STP / OWC.
2. Area & volume of OWC / STP room.
3. Constituent of exhaust gases.
4. Magnitude of each gases from exhaust.
5. Air changes per hour [ACPH]
6. Exhaust air CFM
7. Fresh air quantum. Is it Mechanical or natural
8. Length of the Exhaust duct / contact chamber volume.
9. Velocity of exhaust air in duct work
10. Design & layout of exhaust duct work
11. Efficiency of STP operation. Septic/Anaerobic Condition
12. Oxidant integration technique.
13. Strength (power) & Concentration of Oxidant.
14. Ambient temperature, humidity
15. Air flow & direction – Laminar, static and breeze. For dilution
level.
16. Constant Variation in the quantum of odorous gases.
17. After few years' quantum may increase. (Due to time, efficiency,
performance, etc.)
18. Identification of testing locations. {One may be inside (Indoor)
the OWC & STP & other outside (Outdoor)}.
19. Distance between testing / sampling point & exhaust duct
opening.
20. No. of sample testing & their mean/average.

7. 10%
20%
15%
10%
10%
5%
5%
20%
5%
Ozone Generator Technology 10% Concentration, Strength & Power 20%
Ozone Chemistry With Subject 15% Ozone Reaction Efficiency 10%
Point Of Integration 10% Pre & Post Conditioning 5%
Complimentary Technology Mix 5% Reaction Contact Time 20%
Capacity Of Ozone Generator 5%
Copywrite : This entire Presentation is a copywrite of M/S Chemtronics. It is strictly
prohibited to copy or republish in any form without written permission from Chemtronics
Exhaust Air
Performance
Contributing
Factors For
- Odor
- Microbes
- Pollutants
- Toxic Gases
- Oil & Grease (Kitchen)
9 Performance Contributing Factors

8. Design Basis
1. Literature Review
2. Data from past installed Sites
3. Diversified Practical Experience
4. Stoichiometric Mass Balance Calculation
5. Ventilation Design

9. Design Consideration
1. Magnitude of H2S gas inside STP Room : </= 10.0 ppm
2. Magnitude of Ammonia inside STP Room : </= 10.0 ppm
3. Exhaust Duct Opening from Ground level : >/= 4.0 m
4. Exhaust Duct Opening from compound wall : >/= 4.0 m
5. Sampling point from exhaust duct opening : >/= 2.0 m
6. Single exhaust branch is considered. In case of multiple branches or laterals
provide dedicated model to each branch.
7. If duct length is not sufficient, extra contact / reaction chamber is required.

10. 06 Odor Control Design Criteria – STP Room Exhaust
1. ACPH (Total STP Room Volume) : Minimum 30 (+/- 10%) - Option 1
2. ACPH (STP Room Vol. – Tank Vol.) : Minimum 50 (+/- 10 %) - Option 2
3. Exhaust Air Velocity : Maximum 7.5 m/s (+/- 10 %)
4. Exhaust Duct Length : Minimum 40 M (+/- 5 %)
5. Mechanical Exhaust Air : (ACPH) x (STP Room Volume)
6. Mechanical Fresh Air : 80 % of Exhaust air.
Important Critical Design Criteria’s For STP Room Exhaust Air Odor Control System

11. 07 Odor Control Design Criteria – OWC Room Exhaust
1. OWC Room Area per Machine : Minimum 50 m2 (+/- 10%)
2. OWC Room Height : Minimum 4.0 m (+/- 10%)
3. ACPH : Minimum 50 (+/- 10 %)
4. Exhaust Air Velocity : Maximum 3.5 m/s (+/- 10 %)
5. Exhaust Air Duct Length : Minimum 40 m (+/- 5 %)
6. Mechanical Exhaust Air : (ACPH) x (OWC Room Vol.) + OWC Exhaust
7. Mechanical Fresh Air : 80 % of Exhaust air.
Important Critical Design Criteria’s For OWC Room Exhaust Air Odor Control System

12. 05 Odor Control Design Criteria –
Garbage Collection Room | Waste Segregation Room | Washrooms
1. ACPH : minimum 20 (+/- 10%)
2. Exhaust Air Velocity : maximum 7.0 m/s (+/- 10 %
3. Mechanical Exhaust Air : (ACPH) x (Room Volume)
4. Exhaust Duct Length : minimum 15 m (+/-10%)
5. Mechanical Fresh Air : 80 % of Exhaust air.
Important Critical Design Criteria’s For Exhaust Air Odor Control System

13. 02 Design Criteria – Commercial Kitchen
1. Exhaust Air Velocity : 3.0 m/s (+/- 10 %)
2. Exhaust Duct Length : 25 m (+/-10%) [With / Without ESP]
Important Critical Design Criteria’s For Kitchen Exhaust Air Grease & Odor Control System

14. General
Arrangement
Drawing
• Exhaust Air Treatment
• Odor Reduction by 80% (+/-10%)
• Without any Feed Gas

15. General
Arrangement
Drawing
• Exhaust Air Treatment
• Odor Reduction by 80% (+/-10%)
• Without Any Feed Gas

16. General
Arrangement
Drawing
• Exhaust Air Treatment
• Odor Reduction by 80% (+/-10%)
• With Oxygen As a Feed Gas

17. General
Arrangement
Drawing
• Exhaust Air Treatment
• Odor Reduction by 80 % (+/-10%)
• With Oxygen As a Feed Gas

18. References
• Click here for “Guideline on Odour Pollution & Control” & “Odour Measurement” by
“Central Pollution Control Board, (CPCB) India”.
• Click here for Chemtronics partial “Client List” of Exhaust odour control system
• Sizing mobile App
Click Logo
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19. Thank You
Chemtronics
Technologies (India) Pvt.
Ltd.
Mr. Sunil Shah
022 – 2825 9933
+91– 932 123 4527
sunilshah.Chemtronics
solution@chemtronicsindia.com www.chemtronicsindia.com
Note: Given design criteria are not universal. These are only applicable for
“Chemtronics” Models.