Outline. Mixing fans / Cooling fans. Ventilation means air must. Ventilation. Energy Efficiency for Animal Housing. Environmental Control Systems

Transcription

1 Energy Efficiency for Animal Housing Scott Sanford Sr. Outreach Specialist Developed by Kevin Janni & Larry Jacobson, U of Minnesota Hongwei Xin, Iowa State University Outline Ventilation 101 Energy Conservation Swine Poultry Dairy Questions 2 Ventilation means air must Be exchanged between inside and inside and outside Exit via outlets or exhaust fans Enter via inlets Have cause for airflow Wind Mechanical fans Natural wind and buoyancy Slight vacuum Natural Ventilation Mixing fans / Cooling fans No ventilation no air exchange Local air velocity and mixing Cooling effect in hot weather 3 4 Environmental Control Systems Provide correct amount of air exchange Fresh air and oxygen Remove moisture & gases Remove heat Maintain air quality Low Ammonia / dust Heating in cold weather Cooling in hot weather Goal - Uniform conditions throughout barn Ventilation Environmental Conditions Temperature Humidity Air quality Impacted by Number, age and animal species Manure handling Ambient temperature 5 6 1

2 Animal performance Proper ventilation management enhances: Animal performance Weight gain / egg production / feed efficiency Well-being / Health Respiratory diseases Avoid Too little or too much ventilation Wrong temperature Drafts un-planned air leaks Exhaust Fan Performance Relation between Airflow rate in cubic feet per minute (CFM) AND Static pressure in inches of water (in H 2 O) 7 8 Static Pressure Indicates what the fan must work against Pressure difference Measured with manometer SP for proper ventilation Typical static pressure: 0.05 to 0.12 in. H 2 O Air velocity needed feet per minute Slight vacuum Slotted Inlets Provide and manage inlets Into room Into attic Air Velocity Too low < 800 fpm Poor mixing Too high Drafts / lower air exchange Static pressure directly related to air velocity 9 13 Exhaust Fan Performance All fans are not created equal 2:1 difference in energy consumption for same size fan As fan diameter increases, fan efficiency increases Diffusers / Cones save 12-23% in energy cost HE fans ~ 20% higher energy efficiency Replacement Motors Efficiency?? Performance Data BESS Lab (U of IL) - Independent performance testing Efficiency test data Air Flow per unit of energy XX SP 11 Exhaust Fan Test Data Source: BESS Lab 2

3 Recommended Minimum Efficiency Fan Efficiency vs. Static Pressure Fan Diameter (inches) Recommended Min. Standard efficiency High Efficiency Efficiency cfm/watt 0.05" SP 0.05" 0.05" SP* Excessive SP * Based on fans in the top 25% of fans tested by BESS Lab Source: ASABE EP566.1 Energy Cost Caused by Excessive Static Pressure Layer barn with in (1-HP) fans running continuously. At SP of 0.08 WC, FE = 18.5 CFM/Watt At SP of 0.20 WC, FE = 12.3 CFM/Watt Fans running at 0.20 SP are 66% as efficient as running at 0.08 SP. Running all 80 fans uses 1,432 kwh electricity per day, or about $115 at the rate To achieve the same ventilation rate at 0.2 SP, only 66% of the fans are needed when running at 0.08 SP. Hence, electricity savings is $115*34% saving = $39/day or $3,510 per 90-day summer operation for the house. Stirring Fans Increase air velocity to promote cooling Reduce areas of poor air distribution 15 Circulation Fan Ratings BESS Lab testing ( Thrust efficiency ratio lbf / kw Centerline 5D Thrust is proportional to air flow Thrust Efficiency Ratio (lbf/kw) Circulating Fan Efficiency vs Fan Diameter " Fans 36" Fans 50" to 54" 12" Fans 20" Fans 24" Fans 30" Fans 48" Fans w/guard w/o guard Fans Ave Thrust Ratio Bottom 50% Top 50% Min Target Thurst Ratio Data Source: BESS Lab Compiled by S. Sanford UW-Madison Oct

4 Belt-Driven Exhaust Fan Maintenance Ventilation Exhaust Fan Maintenance Airflow (cfm) 25,000 20,000 15,000 10,000 BESS lab Airflow before belt adj. Airflow after belt adj. Dirty fan shutters can result in up to 40% reductions in airflow Dirty/blocked guards 5, Static pressure (Pa) *** Auto Belt tightener Ventilation Exhaust Fan Attachments Airflow (cfm) 8,000 7,000 6,000 Comparison of 24 fans Shutter & guard only + Wind hood + Discharge cone Wind break for tunnel exhaust fans 5,000 4, Static pressure (in. of water) Wind hoods Discharge cones Source: Bottcher, 2000, Design for windbreak walls, Swine Housing conference Wind Breaks should be feet away from fan Help to disperse odors Source: BESS Lab data What s the performance of this fan? Safety??? Energy Conservation in Midwestern Swine Buildings Developed by Larry D Jacobson, Professor and Extension Engineer 4

5 Energy Use in Pig Production Direct (Fossil Fuel) Energy Primarily L.P. Gas and electricity 2-5% of pig production cost (UMN Farm Financial Management) Indirect Energy (Feed) Feed efficiency, rate of gain Estimated to be 60 to 70 % of pig production costs Annual Energy Use for 600 head finisher (1800/yr) for 3 yrs* Electrical Energy 2006 = 20,211 kwh or kwh/pig prod 2007 = 17,402 kwh or 9.67 kwh/pig prod 2008 = 16,888 kwh or 9.38 kwh/pig prod LP Gas 2006 = 705 gal or 0.39 gal/pig prod 2007 = 1,175 gal or 0.65 gal/pig prod 2008 = 1280 gal or 0.71 gal/pig prod * from Bob Koehler (SW MN) Electricity Benchmarking Swine Units kwh Ave Farrowing kwh / Sow 296 Farrow-Finish kwh/100 lb. 14 Farrow-Nursery kwh/100 lb. 41 Finish kwh/100 lb. 5 Nursery kwh/100 lb. 6 Swine Production Electrical Energy Use 9% 11% 6% 5% 4% Ventilation 39% Lighting Creep Heating Feed Preparation Handling Miscellaneous equipment 2006 Audits in Ontario Canada 21% Other motors Other electrical uses Source: Ontario Ministry of Agriculture RFP Number OSS Source: Ontario Ministry of Agriculture RFP Number OSS Ways to Control Direct Energy Costs Heat Balance Heated buildings in cold/cool weather Reduced ventilation rates Maintain air quality Building Insulation and leaks Environmental Control Set points Proper temperatures for animal size/type Ventilation Fan efficiency = Heat added to room = Heat removed from room Note that ventilation is generally the primary source of heat loss from the room. 5

6 Recommended Ventilation Rates (cfm/pig) Uninsulated Concrete Sidewalls Minimum* Mild Hot weather Sow & Litter (cfm/sow) Nursery 12-30# Nursery 30-75# Finishing # Finishing # Gestating Breeding * Add for unvented heaters based on Mfg. recommendations Updated data from MWPS F Room 0 F Outdoors 6 inch Concrete 34 F Surface Condensation occurs above 25 % RH R= 1.33 Heat Flow Insulated Concrete Sidewalls Manure Pit Ventilation 6 inch 70 F Room Concrete 0 F Outdoors + 1 inch Rigid insulation 62 F Surface Condensation occurs above 75 % RH R= 6.33 Heat Flow Curtain Management - Curtain holes / leaks Sealing Curtain Openings for Winter High infiltration rates Fasten edges during cold weather Wriggle Wire Double layer curtain Reduce heat loss by about half 6

7 Bubble wrap insulation for winter Controllers Temperatures Fans Inlets - % opening Static Pressure Side wall Curtains Lighting Evaporative cooling / misting Staged Heating / Cooling Staged Heating / Cooling Supplemental Heat (Btu/hr) Heater 1 Offset Fan 1 Minimum Ventilation Rate Fan 2 Ventilation Rate (CFM) Supplemental Heat (Btu/hr) Heater 2 Heater 1 Fan 1 Fan 2 Fan 3 Ventilation Rate (CFM) Inside Temperature (F) Inside Temperature (F) Ventilation Controller Setpoints Setpoint temperatures are typically too high 240 lb pigs 60 F Heater and Exhaust Fan Control Avoid large temperature swings Prevent cycling between heating and cooling Heater / Fan offset set too tight. 1.5ºF minimum 4ºF better Temperature Sensor location Near center of building Un- / Overly responsive location Too close to heater / air inlet Shielded from sunlight Oversized/excess heaters Overshoot & Cycling 7

8 Reduce Oversized Heater Output LB White - Throttle Valve (Blue) reduces heater output to 65% of maximum Modine Optional 2 stage Gas Valve 50% or 100% output Temperature Adjustments Animal Desired Temperature (F) Lactating Sow Litter newborn Litter 3 weeks old Pre-nursery (12-30 lb) Nursery (30-50 lb) Nursery (50-75 lb) Growing-Finishing ( lb) Gestating Sow Boar Ramp down temperature based on age / weight Adjust in 2ºF increments Creep Heating Heated Floor Sections Electric Hot water Radiant Heat Heat lamps Infrared heaters Thermostatic Control Creep heating pad Credit: Automated Production Systems Farrowing Crate Hovers Reduced farrowing Room Temperature Energy savings 43% less electricity 45% less gas heat Piglet Survival Slightly less but > industry std. Use for Nursery Piglets Source: L.D. Jacobson, L.J. Johnston, 2008, Save energy in the Farrowing Room with Hovers, University of Minnesota. Bedded Hovers Energy Conservation for Poultry Production Developed by: Hongwei Xin, Director of Egg Industry Center Iowa State University 8

9 49 Egg Production Costs (feed $0.14/lb) Any management that leads to increased feed efficiency will have a major positive impact on profitability of the operation. 7.0% 12.4% 6.7% 5.3% 1.3%3.3% FEED COST 63.9% Feed Costs Pullet Costs Housing & Equip. Utilities Labor Health-related Other 50 Litter & Manure Management Fresh bedding reduces ventilation requirement for IAQ (ammonia) control. Remove litter cakes / new bedding between flocks Application of ammonia-control additives Improved bird performance (weight gain, livability, condemnation, feed efficiency). Minimum Ventilation Rate (CFM/1,000 birds) Min Ventilation for Ammonia Control in Broiler Houses New vs. Built-up Litter 0 Reused litter New litter MWPS Xin et al. (1996) 51 Bird Age (day) 52 Extra LP Use & Cost for Ammonia Control Broiler House on Built-up Litter Ave Outside Temp, F Extra LP, gal for 1 st @$2.50/gal $ 809 $ 924 $ 1, $ 880 $ 1,006 $ 1, $ 952 $ 1,088 $ 1, $ 1,024 $ 1,170 $ 1, $ 1,096 $ 1,252 $ 1, $ 1,239 $ 1,416 $ 1,770 Barn - 40 ft x 500 ft with 24,000 birds Bedding Cost for 20,000 ft 2 Floor & Benefit from Possible Improved FC Ammonia Emissions of Broiler Houses Impact of New vs. Built-up Litter 24 tons of bedding (e.g., oat hulls) needed $70 per ton of bedding $1680 per house of 20,000 ft 2 floor area Assuming feed conversion improved 2.0 to 1.96 at market weight of 6 lb/bird 95% livability (24,000 initial placement) Cumulative NH 3 Emission, g bird Built-up litter Built-up litter Downtime New bedding New bedding Downtime 53 Feed savings est per flock - $ Bird age, d Burns et al. (2007) 9

10 Impact of Manure Removal Interval on Ammonia Emission Layer House - Manure-Belt Houses Drying Manure in Manure-Belt Layer Houses 55 NH3 ER (g/hen-d) y = x x R 2 = Accumulation time (d) Source: Ning ISU ( Use of Exhaust Air Forced Air Blowers Courtesy of Tom Lippi, CTB 57 Topical Application of Chemical Additives to Reduce Ammonia Alum lbs per 1000 ft 2 floor area Effective for about 2 to 3 weeks, respectively Ferric Sulfate (Klasp TM ) 100 lb per 1000 ft 2 In-house Ammonia (ppm) ppm, Critical Ammonia Level Weeks Untreated litter Alum treated litter Moore et al. (2000) 58 Heating Systems Control & temperature sensor calibrated? False readings lead to: Increased fuel use Bird stress (too hot) or increased feed energy (too cold). Thermostat or temperature sensor location Measuring what the birds are exposed to? Heater maintenance Annual Cleaning Gas pressure regulator checked Pilot / Igniter Heating Systems (cont d) Uniform temperature distributed? Adequate mean temperature does not necessarily do justice! Ave daily feed intake g per laying hen Varying from g through the house Leads to undesirable egg size distribution. Heating Systems (cont d) Avoid placing space heaters next to exhaust fans it is a waste of energy! Replacement of old brooders with new, energy efficient brooders/heaters

11 Heating Systems (cont d) Pancake vs. Radiant Brooders Heating Systems (cont d) Brooder Type Install Ht, ft Floor Coverage Conv. pancake < 3 ft 6-8 ft diameter Modern radiant 5 6 ft ft dia. Air leaks at ground level Insufficient number of brooders Source: M. Czarick, UGA (Feb, 2011) 62 Source: M. Czarick, UGA (Feb, 2011) Temperature Recommendations Type Floor Temperature (F)* Building Temperature (F) Broiler Chicks 3-7 days 90-95F 75-80F Broiler Chicks 2nd week 85-90F 70-75F Broiler Chicks 3rd week 80-85F 73-75F Broiler Chicks 4th week 75-80F 72-73F Broiler Chicks 5th week 70-75F 70-72F Broiler Chicks >5 weeks 65-70F Mature birds & Turkeys 55F min. * ~ 3/4F reduction per day for 6 weeks, 1976, Poultry Housing and Handling, Bul , British Columbia, Ministry of Agriculture, Food and Fisheries R.Meunier, M.A. Latour, 1999, A guide for housing, Brooding and Handling Chicks Safely, AS-527, Purdue University Cooperative Extension. 64 Ventilation Systems Sufficient ventilation capacity for winter and summer conditions Efficient use of resources Adequate air change to avoid condensation in winter Maximize cooling effect in summer Maintain proper static pressure Uniform distribution of air in the barn the less temperature gradient, the better. Good management decisions use of nocturnal (night-time) cooling. Recommended Ventilation Rates (MWPS-32, 1990) Animal Unit Cold Mild Hot CFM/Unit Broilers 0-7 d head > 7 d lb Layers lb Turkeys Poults head Growers lb Air Flow Pattern in Animal Houses To increase cooling effect by helping birds lose body heat faster Air stream Cross Ventilation Air stream Tunnel Ventilation Note: Add 2.5 CFM per 1000 BTU/hr of unvented heating 65 11

12 67 Effect of Air Velocity as Affected by Ventilation Mode Cross vs. Tunnel A broiler barn with a dimension of 40 x 400 ft and a drop-ceiling height of 10 ft. Determine the average air velocity through the house if cross or tunnel ventilation is used to ventilate the barn at 100,000 CFM air flow. Q V = Q = 100,000 CFM A For cross ventilation: A = 400 x 10 = 4000 ft 2 V = 100,000 / 4000 = 25 ft/min For tunnel ventilation: A = 40 x 10 = 400 ft 2 V = 100,000 / 400 = 250 ft/min Effective Temperature vs. Air Velocity for Broiler Chickens 68 Effective Temperature, F Air temp = 90F (250ft, 78F) Air Velocity, ft/min 69 Natural Ventilation Save Energy & Achieve Better IAQ It doesn t take much wind that blows in the right direction to meet the barn s air change need. Wind can often bring in more fresh air than the ventilation fans are capable of doing. 70 Air Change Per Hour (ACH) Wind-Induced Ventilation E-W Oriented Turkey Barn* ft C.O. 2-ft C.O. 1-ft C.O. C.O. = curtain opening Wind Speed, mph (45 deg from due south) (*50 x 600 x 10 ft) Stirring/Cooling Fans vs. Tunnel Ventilated Dairy Electrical Energy Use Manure handling 4% Electric water heating 4% Feeding equipment 3% Miscellaneous 1% Milk cooling 25% Vacuum pumps 17% Anecdotal field data in Iowa indicate: TV fans are more efficient in cooling the birds and creating more uniform air in the barns than stirring fans TV led to improved body weight gain and feed conversion The producer has converted all his barns from conventional to TV Lighting Ventilation 24% 22% Ludington and Johnson, Dairy Farm Energy Audit Summary,

13 Dairy Ventilating Systems Natural ventilation Without mixing fans With mixing fans Mechanical ventilation Exhaust fans with inlets Tunnel ventilation Cross-ventilated Natural Ventilating Systems Large sidewall openings Ridge opening Sited to catch summer winds Avoid obstructions Mixing / Stirring fans Axial fans High Volume Low Speed (HVLS) fans Axial mixing fans 36 to 48 inch diameter Direct or belt driven Multiple fans Mixing and cooling Mount at angle towards cows Increases air velocity to increase cooling effect Typically 2-3 rows per pen at 30 or 40 ft spacing High Volume Low Speed (HVLS) fans 8 to 24 foot diameter Low speed (RPM) and air velocity Few fans and less horsepower Mixing VFD Controls Savings 4.3 kw per hour (24ft) Compared to HS fans Mechanically Ventilated Dairy Barns Tunnel ventilation for hot weather Air stream Cross-ventilated year round Air stream Xin,

14 Tunnel Ventilated Barns Tie Stall or free-stall barns Fans at one end, inlet at other end Cross Ventilated Barns Free-stall barn Fans on one side and inlet on other side Low pitched roof Baffles drive air to cow level Fans and lights required year round Cross-ventilated barn Exhaust fans Livestock Waterers Electrical Safety!!!! And Energy Savings Evaporative Pad Inlet 82 Frost-Free Livestock Water Fountains Energy Free Fountain Installation Save $60 to $100/yr Plus Poorly maintained waterer can use $200+ in electricity/yr May not be suitable for low numbers of animals Check manufacturers recommendations May require a low wattage heater With Thermostat Requires daily maintenance during sub-zero temperatures Check that covers / balls are not frozen open or closed Research studies in Manitoba and North Dakota found they performed acceptably without heaters

15 85 SUMMARY Energy conservation higher profitability Energy conservation can be achieved by: proper design operating within optimal environmental conditions Using natural ventilation when conditions permit Using tunnel ventilation in summer Avoid high static pressures Indirectly improved feed efficiency. Summary New Fans Fan efficiency BESS Lab Ammonia from manure increase ventilation requirements Creep heating & hovers reduce heating 14 FAN MAINTENANCE is important 15