1. FARM ENERGY Energy Efficient Fans for Swine Production F ARM E NERGY PM 2089E

2. FARM ENERGY PM 2089M (USDA Census of Agriculture, 2007)

3. F UNCTION OF E XHAUST F ANS : To provide the QUANTITY of air being exchanged I MPORTANCE OF E XHAUST F ANS : To provide healthy air quality for pigs and workers −Control heat −Control moisture −Control ammonia, methane and hydrogen sulfide FARM ENERGY PM 2089E

4. T ERMINOLOGY : cfm is the cubic feet of air exhausted per minute inches of water is the static pressure (difference between indoor and outdoor air pressure) cfm/W is the energy rating in cfm per watt of electricity FARM ENERGY PM 2089E

5. FARM ENERGY Inside Open tube Outside Static Pressure Measurement Inches of water Lower pressure inside building draws fluid up Difference is “inches of water” Normal range is 0.05 to 0.1 inches of water

6. E XAMPLE 24” F AN D ATA Static Pressure Inches of water Speed RPM Airflow cfm Efficiency cfm/W 0.001101649016.1 0.051094609014.7 0.101089574013.4 0.151083525012.2 0.201082476010.8 0.25108239509.0 0.30108223305.6 Source: BESS (2009) FARM ENERGY PM 2089E

7. H OW E FFICIENT S HOULD Y OU C HOOSE ? Diameter of fan (in)Efficiency Rating (cfm/W) @ 0.1 inches of water Median RatingTop ¼ Rating <167.98.7 16 to 2010.311.2 22 to 3513.014.6 36 to 4615.917.2 48 to 5618.920.4 >5620.121.5 Consult your electric utility provider for standards on possible rebate programs! Source: BESS (2009) FARM ENERGY PM 2089E

8. T O FIND TEST DATA : www.mwps.org (to order) A CCESS FAN DATA ONLINE AT : www.bess.uiuc.edu FARM ENERGY PM 2089E

9. I S IT WORTH IT TO REPLACE AN OLD FAN ? M OST E FFICIENT 24” FAN 6980 cfm @ 0.1 in water 17.1 cfm/W Runs 8760 hours/yr L EAST E FFICIENT 24” FAN 6190 cfm @ 0.1 in water 9.9 cfm/W Runs 8760 hours/yr 6190 cfm x 8760 hrs 9.9 cfm/W x 1000 W/kW = 5477 KWh/yr 6980 cfm x 8760 hrs 17.1 cfm/W x 1000 W/kW = 3576 KWh/yr FARM ENERGY PM 2089E Savings of 1901 kWh or $190 per year (at 10 cents per kWh)

10. D IRTY F ANS AND S HUTTERS : 1/8 inch of dirt or dust can cause as much as 40% reduction in fan and shutter air flow Therefore, also a 40% reduction in efficiency FARM ENERGY PM 2089E

11. S UMMARY : Efficient fans can save money Choose fans in the upper ¼ rating for like sizes Maintain and clean fans for optimal performance Check with local electric provider for rebate opportunities before buying new fans FARM ENERGY PM 2089E

12. FARM ENERGY F OR M ORE I NFORMATION : Google “ISU farm energy” or visit us online at http://farmenergy.exnet.iastate.edu Download ISU Farm Energy publications at no charge Follow us on Twitter @ISU_Farm_Energy for updates Ask your local utility provider to contact us! http://farmenergy.exnet.iastate.edu

13. FARM ENERGY http://farmenergy.exnet.iastate.edu