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. 3. 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

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

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

Air Supply Unit Filter Adsorbent Blower

Air Supply Blower 198 m3/h (117 cfm)

Air Supply Unit

Air Supply Filter 22.4 kg of adsorbent Charcoal Permanganate Zeolite

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

BCFC Inlet

Stainless Steel Lining

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

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

End View Sampling point Air Inlet Air Outlet Divider 31 cm

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.

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.

Instrumentation Room Manifolds Gas sensors PC

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

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

Emission Rate of N-Butanol 12 155 2 Emission Rate = 5.10 Log(C) - 13.05 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

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

Lagoon Effluent: NH3 Emission 400 2 300 Emission Rate, mg/hr-m 200 Emission Rate = 4.15x - 18.1 R 2 100 = 0.90 20 40 60 80 100 120 Lagoon Effluent Dilution, % Solids: 0.16%

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

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

Deployment

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

Chamber Inlet and Outlet Samples hebervacus

Emission vs. Air Speed Surface Air Speed, m/s Measured Predicted 4 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

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.

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

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

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

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

Conclusions Low sampling variance

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

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

Odor emission rate increased Conclusions Odor emission rate increased for 1000-20,000 ppm n-butanol hood5-7

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

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