ventilation systems for swine production - purdue … · ventilation systems for swine production...

36
Ventilation Systems for Swine Production Jay Harmon, Ph.D., P.E. Professor Agricultural & Biosystems Engineering

Upload: lamtram

Post on 08-Apr-2018

248 views

Category:

Documents


4 download

TRANSCRIPT

Page 1: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Ventilation Systems for Swine Production

Jay Harmon, Ph.D., P.E.Professor

Agricultural & Biosystems Engineering

Page 2: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Ventilation Systems Affect:

• Air temperature• Moisture level• Air temperature uniformity• Air speed across animals• Airborne dust and disease organism levels• Odor and gas concentrations• Combustion fumes from unvented heaters • Moisture condensation on surfaces

Presenter
Presentation Notes
Ventilation affects many aspects of the animal environment.
Page 3: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

How Important is Ventilation? Actual Case in Hamilton County

• 30 % death loss– Cohorts at ½% death loss

• Complete new ventilation system– ½% death loss

• 200 pig nursery – losing 60 pigs/turn– Worth $35 each - $2100 loss each turn– Paid for in one turn

Page 4: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Negative-Pressure Ventilation Systems• Exhaust fans• Air inlets• Controls

• Total [HVAC] system– Heaters– Evaporative cooling

Vacuum or “negative pressure”

Presenter
Presentation Notes
Ventilation systems include three basic components, but may be much more complex.
Page 5: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Terminology

• cfm: Cubic feet of air exhausted per minute

• fpm: Air speed in feet per minute

• inches of water:Static pressure (difference between indoor

and outdoor air pressure)

Presenter
Presentation Notes
‘Airflow’ is a broad term that means different things to different people. The units used can really help define what is being measured and discussed.
Page 6: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Recommended Ventilation Rates (MWPS)

Sow & Litter 20 cfm/sow 500 cfm/sow

Nursery 12-30# 2 cfm/pig 25 cfm/pig

Nursery 30-75# 3 cfm/pig 35 cfm/pig

Finishing 75-150# 7 cfm/pig 75 cfm/pig

Finishing 150-250# 10 cfm/pig 120 cfm/pig

Gestating 12 cfm/sow 150 cfm/sow

Breeding 14 cfm/sow 300 cfm/sow

Minimum Hot weather

Presenter
Presentation Notes
Note the wide variation in rates for different types and sizes of pigs, as well as season. In many cases, the numbers listed are likely to increase as data shows that modern lines of hogs produce more body heat (natural consequence of more-productive, faster-gaining hogs… which is a different concept than hogs being more efficient users of feed). Note that ‘minimum’ rate is often used interchangeably for cold-weather rate. May want to note difference between ‘minimum ventilation rate’ and ‘minimum recommended rate’, especially as it applies to hot weather.
Page 7: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Example Design: 500 head nursery• Pigs enter at 12 lbs, exit at 60-70 lbs.• Minimum Ventilation

– 500 pigs x 2 cfm/pig = 1000 cfm• Maximum Ventilation

– 500 pigs x 35 cfm/pig = 17,500 cfm• Steps between?

Page 8: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Choosing Exhaust Fans

Presenter
Presentation Notes
New section. Tab. Exhaust Fans Exhaust fans for a a tunnel ventilated 100’ wide double room wean to finish facility. The fan capacity for each room is designed for 60 cfm per pig conventional (pit fans and one end-wall fan) before it goes into tunnel ventilation.
Page 9: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Fan Test Data

Static pressure Speed Airflow Efficiencyin. H2O rpm cfm cfm/W

0.00 1,642 2,150 9.2 0.05 1,638 2,020 8.5 0.10 1,635 1,840 7.7 0.15 1,653 770 3.5 0.20 1,641 650 2.8

0.25

BESS Lab

Presenter
Presentation Notes
Highlight desired static pressure range. Point out that fan speed may not change much with changes in static pressure, but airflow delivered and fan efficiency both fall off noticeably at higher static pressures. So… more resistance equals less airflow, greater cost to deliver each unit of airflow, and likely a hotter-running fan motor (shorter motor life expectancy).
Page 10: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Fan Types

Pit Fans

Wall Fan

Presenter
Presentation Notes
Point out how the fan is not restricted in these arrangements. Also, there’s little chance of manure – fan contact.
Page 11: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Example Fan Selection

CFM goal

Fan No.

Model CFM rating

Control Method

Total CFM

1000 to 1500

1 14” Acme 2030 VS 2030

4000 2 14” Acme 2030 VS or SS 4060

8000 3 20” Del Air 4210 SS 8270

17,500 4 36” Airstream 9900 SS 18,170

Page 12: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Fan Layout• 20 pens of 25 pigs• 8’ by 10’ pens

1

2

3

4

40’

44’

Page 13: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Raydot Center Air InletAir Inlets

Presenter
Presentation Notes
New section. Tab. Air Inlets Bi-flo counter weighted ceiling inlet.
Page 14: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Primary Roles of Air Inlets

• Distribute air throughout room as intended• Help maintain desired conditions in animal

zone [microclimate]

Presenter
Presentation Notes
Two slightly different, but equally essential functions.
Page 15: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Proper Air Distribution at Minimum Airflow Rate

End view of room

Presenter
Presentation Notes
Cold incoming air mixes with warm room air and slows down before reaching the pig space. What happens if the inlet opening is too large? …too small? Remember that the fan setting is usually controlled by something other than the inlet setting. This is a case (at the inlet) where air speed and airflow rate are inversely related. As the inlet is opened up, air speed decreases proportionately, while the flow rate through the opening probably increases somewhat.
Page 16: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional
Presenter
Presentation Notes
Inlets and exhaust fans work best as a system when the inlet air velocity and room static pressure are in the range shown.
Page 17: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Manometer (measures static pressure)

Presenter
Presentation Notes
This sort of tool is very important for managing a ventilation system. Unfortunately it is often absent, unused or not understood in actual livestock buildings.
Page 18: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Adjustable Opening

Presenter
Presentation Notes
Things to check for on inlets include: maximum open [throat] area, smooth regulation of opening, and ease of making adjustments.
Page 19: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Air Inlet Open on One Side

Presenter
Presentation Notes
The 4-way air inlets are closed on three sides and every other inlet pointing toward the outside wall is closed. The iso-wean pigs in this room were approximately 1 week old. With the low ventilation rates and small pigs, the producer wanted to direct airflow towards the outside wall and to make sure the open inlets would open. With this style of inlet and the placement, it is important to close off the opposing inlets going down the length of the room. If left open, the opposing air streams will cause a draft over the dividers in each pen.
Page 20: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Inlet Layout• Maximum 18,000 cfm• Need 15 inlets rated

at 1200 cfm each• Use 16

Page 21: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Attic Air Intake

• Port of entry for fresh air

• Must be effective opening

Presenter
Presentation Notes
Attic intake needs to be unrestrictive.
Page 22: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Attic Opening Needed

• Attic air intake (sq. ft.) = total hot- weather ventilation (cfm)/400 fpm

• Said another way…– Provide 1 square foot of opening for every

400 cfm of airflow• Example: Given 18,000 cfm

– 18,000 cfm/400 = 45 sq. ft. of opening

Presenter
Presentation Notes
We never want the building’s air intake to be more restrictive than the room inlets. That’s why we design for a slower air speed (400 fpm) and larger resulting open area. Note that the example uses same airflow rate as in previous scenario for inlets.
Page 23: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Unacceptable Air Intake

Presenter
Presentation Notes
Effective opening is only a fraction of the slotted vent area. Effective area is likely to be further reduced by debris collecting in slots.
Page 24: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Inlet Layout• 350 btu/hr-pig• ~175,000 btu/hr• Use 2 heaters

Page 25: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Controller

Page 26: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Set Point

Temperature

6

7

8

1 Variable-Speed & 3 Single-Speed Fans

Differential 2

Stage 2

3

Differential 3

Stage 3

4

Minimum

Airflow rate

Differential 4

Stage 4

5

Stage 1

Bandwidth 1

1

2

9

10

2 F 2 F 2 F 2 F

50%

?

Page 27: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Heater offset [1.5 oF] ensures heater is off when 1st stage fans are functioning

Page 28: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Tunnel Finishing

Page 29: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Tunnel – Pit Fans

Page 30: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Tunnel Endwall Curtain

Page 31: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Tunnel – 300 fpm “wind”

Page 32: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Inlet Openings

Page 33: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Ventilation Curtain

Page 34: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Curtain Controller

Page 35: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

The Right System?

• Tunnel– Creates a “fake”

wind– More Fans– More Electrical

Usage– Cooling Potential– More Prescriptive

Management– Backup Needed

• Curtain Sided– Uses natural

weather patterns– Curtains vs Fans– More LP Usage?– Calm Days Difficult– Transition Difficult– Curtain Drops

Page 36: Ventilation Systems for Swine Production - Purdue … · Ventilation Systems for Swine Production Jay Harmon ... The f\ൡn capacity for each room is designed for 60 cfm per pig conventional

Questions??

Good Resource for further information:

www.mwps.org