1. Agricultural and Biological Engineering Purdue University
Albert J. Heber, Associate Professor Director, Purdue Agricultural Air Quality Lab
Building Environment
Research & Education
AgAirQuality.com
Agricultural and Biological Engineering
Purdue University
Today we are going to discuss and demonstrate the BASICS of NATURAL VENTILATION. These fundamentals will help you to select and manage your naturally ventilated buildings.
Objectives:
1. To explain and demonstrate nonnegotiable underlying principles of natural ventilation.
2. To discuss types of natural ventilation in livestock buildings and how these concepts apply to them.
To present my recommended naturally ventilated building .. the one that I would build and why.
4. To discuss troubleshooting of natural ventilation problems.
See handout with visuals

2. A.J. Heber, T.T. Lim, J.Q. Ni and K.J. Fakhoury
“A Buoyant Convective Flux Chamber for Measuring Liquid Surface Emissions”
A.J. Heber, T.T. Lim, J.Q. Ni and K.J. Fakhoury
AgAirQuality.com
hoodsunny

3. Objectives Develop floating emission chamber Evaluate performance
Field Tests
1.      Design and construct a new buoyant convective flux chamber (BCFC) for measuring gaseous emissions from liquid surfaces of dilute wastewaters such as anaerobic lagoons.
Lab Tests

4. Air Supply Unit
Filter
Adsorbent
Blower

5. Air Supply Blower
198 m3/h
(117 cfm)

6. Air Supply Unit

7. Air Supply Filter
22.4 kg of adsorbent
Charcoal
Permanganate
Zeolite

8. Stainless steel divider Styrofoam boards for buoyancy
Top View
Liquid surface area = 0.76 m2
Air velocity probe
Air inlet
Air outlet
Stainless steel divider
Sampling location
Styrofoam boards for buoyancy

9. BCFC Inlet

10. Stainless Steel Lining

11. “Hairpin” Airflow Path
2.4 m path length
2.2 sec residence time

12. Side View Air inlet Air velocity probe Air outlet Sampling location
1.1 m/s

13. End View
Sampling
point
Air Inlet
Air Outlet
Divider
31 cm

14. Lab Tests N-butanol at 250-20,250 ppm in 200 L water
Odor emission only.
Lagoon effluent: 100, 50 and 25% dilution
H2S, NH3, CO2 and odor emission.

15. Gas Analyzers Ammonia (0 to 200 ppm)
Ammonia converted to nitric oxide with a SS converter, 875 C
Chemiluminescense: PMT detects light emission from reaction of nitric oxide with ozone.
Sample flow rate = 0.5 Lpm
Hydrogen sulfide (0 to 10,000 ppb)
Hydrogen sulfide converted to sulfur dioxide, SO2
Pulsed fluorescence: PMT detects UV from decaying SO2 molecules
Sample flow rate = 1.0 Lpm
Carbon dioxide (0 to 5,000 ppm)
Photoacoustic infrared sensor
Sample flow rate = 1.0 Lpm.

16. Instrumentation Room
Manifolds
Gas sensors PC

17. Odor Threshold Measurement
1 of 8 panelists
Olfactometer
Tedlar
bag PC
Panel leader’s hand

18. N-Butanol Test Results
Blank: 9 OU
Inlet mean: 10.4 OU (8 to 13 OU)
Odor emission: 0.5 to 11.2 OU/s-m2

19. Emission Rate of N-Butanol12
155 2
Emission Rate = 5.10 Log(C) 8 2 R
= 0.82
Emission Rate, OU/s-m 4 63 51 20 27
100
1000
10000
100000
Concentration of N-butanol in Tank, ppm

20. Lagoon Effluent Test Results
Inlet mean: 22 OU
Outlet mean: 27 OU
Odor emission: 0.8 OU/s-m2 at 100%
Hydrogen sulfide too low to measure
Inlet ammonia mean: 1.8 ppm
Outlet ammonia mean: 2.9 ppm
Ammonia emission proportional to effluent concentration.
Ammonia levels below odor threshold

21. Lagoon Effluent: NH3 Emission
400 2
300
Emission Rate, mg/hr-m
200
Emission Rate = 4.15x R 2
100
= 0.90 20 40 60 80
100
120
Lagoon Effluent Dilution, %
Solids: 0.16%

22. Field Tests Swine grow-finish facility Four consecutive days
Day 1: Effect of air speed
crustincorner

23. Anaerobic Treatment Lagoons
Six Swine Buildings
1st Stage Basin
2nd Stage Basin

24. Deployment

25. Odor Emission Tests Raceway (6 m) 3 Lpm Air velocity control pumps
Evacuation chamber
hoodwtwovacs
Hammer

26. Chamber Inlet and Outlet Samples
hebervacus

27. Emission vs. Air Speed Surface Air Speed, m/s Measured Predicted4
Measured
Predicted 3 2
Emission,
OU/m2-s
0.93
Emission = 1.85 x 1 2 R
= 0.88
0.0
0.5
1.0
1.5
2.0
Surface Air Speed, m/s

28. Field Test Results Inlet mean: 23 OU (12 to 42 OU) Outlet mean: 52 OU
Odor emission: 1.5 to 2.1 OU/s-m2
Mean of 1.7 OU/s-m2 corresponded to 1,000 ppm n-butanol.

29. Advantages Large air filtration and cleaning unit Inlet air sampling
Large liquid surface area
Long air path

30. Disadvantages Size (van or pickup required)
Weight (2-4 people required)
Gentle berm slopes required, >3:1
Limited reach (five meters)

31. Future Research Reduce size and weight
Evaluate and improve internal air profiles
Study effect of flow rate on emission

32. Good comparative measurements of gas and odor emission rates
Conclusions
Good comparative measurements
of gas and odor emission rates

33. Conclusions
Low sampling variance

34. Lower detection limit: 500-1000 ppm n-butanol.
Conclusions
Lower detection limit: ppm n-butanol.

35. Lower limit reached with properly designed swine lagoon
Conclusions
Lower limit reached with
properly designed swine lagoon
“Low odor” lagoon
0.16% solids

36. Odor emission rate increased
Conclusions
Odor emission rate increased
for ,000 ppm n-butanol
hood5-7

37. Acknowledgements Purdue University Agricultural Research Program
State of Indiana Value Added Research Program
Ramco Sales, Inc.

38. Check out AgAirQuality.com
Questions?
Check out AgAirQuality.com
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