CHICK-LEVEL TEMPERATURE A CONTINUING CHALLENGE IN BROILER HOUSES Eileen F. Wheeler, Assistant Professor Environment Control Agricultural and Biological Engineering What is the temperature at bird level in a broiler house? Is it the same as the temperature at the heater thermostat hanging five feet off the floor? I think we are all inclined to say “no.” It would be cooler nearer the floor at bird level. Most fan and heater thermostats in broiler houses are at about eye level for ease of operator adjust ment Many growers follow the good practice of hanging a ther- LAND PRIDE Clear and Clean... * c* Powered Rakes • 72” and 96” models available • 20 degree left or right angling capabilities • Optional Danish Tine Kit with staggered rows • Heavy-duty gauge wheels with sealant • Heat treated material control blade • Ideal for clearing rocks, debris and even beaches Keep your jobsite labor at a minimum with Land Pride’s PTO Powered Rake Betts Equipment 3139 Windy Bush Road, Rt 232 New Hope, PA 18938 215-598-7501 Hoober, Inc. Mam Street Intercourse, hA 17534 717-768-8231 Hoober, Inc. East Mam Street McAhsterville, PA 17049 717-463-2191 Deerfield Ag & Turf Center, Inc. RR 2 Box 212 Watsontown, PA 17777 717-538-3557 Detlan Equipment, Inc. 141 East Main St Silverdale, PA 18962 215-257-5177 Thomas L. Dunlap Rt. 220, Main St. Exit Jersey Shore, PA 17740 717-398-1391 Eckroth Bros Farm Eqbipment Rd 2, Box 24A New Rmgold, PA 17960 717-943-2131 New Jersey Rodio Tractor Sales North White Horse Pike Hammonton, N J. 08037 609-561-0141 Warren County Service Center 228 Route 94, Blairtown, N.J. 908-362-6916 momctcr alongside the thermostat to further check temperature. But the temperature at human level is warmer than floor level in a house using furnaces. Brooders partially compensate for this problem by directing their heat right at the tar get: the chicks on the flow. But is the temperature right for the birds under a brooder? How close is the floor temperature to chick target temperature for a house using either unit furnaces or brooders, or both? The goal has been to provide from 85-90 degrees F floor temperature for chicks on the day of placement and then to drop that temperature about one degree each day until the birds arc at about 70 degrees F for the final week. In order to have an 85 de grees F floor temperature, a Pennsylvania Eckroth Equipment Co. 4910 Kernsville Rd Orefield, PA 18069 610-366-2095 .Hines Equipment RT. 220, Belwood, & 814-742-8171 Keller Brothers R 7 Box 405 Lebanon, PA 17042 717-949-6501 1950 Fruitville Pike Lancaster, PA 17601 717-569-2500 M.S. Yearsley & Sons West Chester, PA 610-696-2990 Pikeville Equipment Inc. RD 2, Oysterdale Road Oley, PA 19547 610-927-6277 Stoltzfus Farm Service Cochranville, PA 610-593-2407 Stouffer Bros Inc. 1066 Lincoln Way West Chambersburd, PA 17201 717-263-8424 Frank Rymon & Sons, Inc. RD 3, Box 355 Washington, N J. 07882 908-689-1464 furnace-heated house would need an air temperature around 90 de grees F. Growers realize the im portance of providing proper temperature for day-old chicks and preheat a furnace-house for around 48 hours in an attempt to get the house back up to the 90 de grees F temperature after the cleanout period. Many growers are unaware of how cool the floor temperatures are in their houses. The past winter (1997-1998), the Pennsylvania Broiler Research Program funded a study of en vironmental conditions within Pennsylvania broiler houses. One major objective of the study was in ammonia monitoring, which was reported in a previous article, but some interesting findings re lated to temperature conditions in the houses arc repeated in this arti cle. Three broiler houses at one in tegrator company were selected. These houses were as similar to each other in size, age, type of construction, equipment (waterers and brooders, in particular), and litter conditions as possible. All houses had forced-air unit heaters. Additional criteria to minimize variability amone the farms and trails were same bird breed and similar bird age (within one week). Environmental data collections were primarily electronic using small, portable sensors with data loggers. One set of outdoor temperature (T) and relative humi dity ((RH) sensors at each farm provided a sense of the challenge faced by each house’s environ mental control system. Inside, three sets of T and RH sensors were used to determine any varia tion in interior conditions due to stratification or uneven heat and fresh air distribution. Two sets were centrally located one above the other. One of these sets was lo cated near bird level about 12 inches off the floor, in a protective cage, and the second set hung on a thermostat about five feet off the floor. The third sensor set was lo cated at bird level nearer a side wall exhaust fan. Heaters were positioned along the sidewall op posite this exhaust fan sidewall. Temperature stratification is a well-known consequence of fur nace use, particularly at minimum ventilation rates. Furnaces direct the heated air well into the room but when the ventilation system inlets do not provide adequate mixing of this heated air with cooler outside air, there is little reason for the hot air to drop to floor level. Warmer air accumu lates nearer‘the ceiling where it is only disturbed when the timer fan comes on, the inlets open, and some fresh air exchange and mix ing occurs. Undersirable tempera ture stratification is a consequence. of the combination of inadequate timer fap/inlct and funmcc yse. Compounding the stratification problem is that thermostat height' for heater control is often posi tioned at human shoulder level. Temperature at this height may in deed be appropriate for chicle comfort and health but unfortun- Broiler House Temperature Stratification 100 1— u. 70 | 60 & o> Q 50 20 4 &00 ately, the chicks are down on the floor. Temperature at the lower stratification to develop. There is 'chick level is usually cooler due to less “dead air time between fresh temperature stratification. nir mixing cycles. A more uniform A look at an example using data temperature will be maintained in from last winter’s study demon- the house by adopting five-min strates the problem. The figure i ute timers, shows temperature stratification * Mixing fans can be an effcc with a reasonable temperature of five, if expensive, solution. These around 88 degrees F being main- f BO5 (typically 24- to 36-inch dia tained at thermostat height of 5 meter) are hung from the ceiling to feet from the floor while the mix air horizontally within the chicks arc exposed to 81 to 84 de- house. They arc spaced cveiy 50 grees F temperatures near the f®®t i®® i®® l down middle floor. The floor level temperature °f house and positioned to was a bit warmer in the building avoid wind ®hill on the chicks, center than nearer the sidewall ex- Th® expense of mixing fans is m haust fan location. Infiltration initial fan purchase, wiring for m from the fan louvera or being far- stallation and electricity use. thest away from the heater units Ideally, weU-designed and proper likely contributed to the cooler managed mlcts on the vcntife sidewall temperatures. Uon system should accomplish the The cool floor level tempera- sa “ c “motion, turcs were not unique to this flock. suggestion would be to un- Day 1 floor level temperature in plement the top three soluUonsbe the nine flock cycles under study adopting mixing fans. To a averaged 84 degrees F. Four ventilation engineer, mixing fens flocks had an 81-82 degrees F as a wmtervenUlation solution are , . . JK a “cosmetic fix to a more funda startmg temperature while one . . .. . .. _ T flock had the desired 90 degrees F mental venulahon pmblem. In floor level temperature. solve the problem What To Do About and may be the best option for old- Tcmpcraturc Stratification er ’ loosel Y construc H* houses • Position thermostaats or sen- , staUc P rcssure difference is sors nearer bird level than at difficult to maintain and/oi-the in human height. It will cost more in ,ots cannot throw air into the mid time than cable to drop the sensors d,e of * hc house ' Adoption of bird down near bird level, but some level temperature sensors five growers are already doing this. minute tuners and more effective Certainly, new construction and functioning will be better ventilation equipment upgrades 50111110115 ' b * a should include bird level sensors laI15 ; ~ ... ~ whether they are connected to Finally even with improvedTea thermostats or electronic controll- ** management m place, ers. With lower sensors, a grower what a « rowCT or a service would have known that the birds P 6 do to momtor temperature in our example were at 83 degrees level? Consider purchasing F, not 90 degrees F, and could temperature measuring instru have taken corrective action. ■. - ments. Certainly, even a cheap • Make sure minimum (55-$ 15) hung at lion is used cffcclivdy. This levefis a good indicator of air oftn accomplished witfiohe or temperature. Hand-held T and RH timer-fans in the-’ittoiicr hous£ J6sstruments.(sso-$I00) will allow brooding section. readings to be taken at any place Minimum ventilation provides m the house. Infrared temperature air exchange by removing stale, sensors (approximately $200) are moisture-laden air and replacing it gaining use in broiler houses, with fresh air. Minimum vefitila- Thedc hand-held instruemnts tion also, just as importantly, pro-' sense the temperature of a surface, vides mixing of this fresh air with such as the floor, rather than the room air. A properly operating in- mr temperature. These tools to let will destratify the room air. In- gether can be diagnostice in deter lets operate effectively with at mining whether appropriate least a o.osinch static pressure dif- temperature at floor levels is being ference which will ensure that air provided for the birds. There are enters the house with enough ve- a^so electronic sensors with built locity (700-1,000 feet per minute) m dataloggers ($lBO per unit plus to provide good air mixing. supporting software) that can • Five-minute timers are recom- monitor temperature and relative mended. Ten minutes timers have humidity every few minutes, been . more-commonly used on More information on use .of these mtniftium ventilation timer fans units will be in an upcoming arti yet especially in the brood clutaa- " o-T ’ „ ber, an upgrade to five minute tim- Temperature stratification will ers' will miprove temperature coil- ’ “““"IF pew m-hfoller houses, ttol. Rather-than using a ten-min- ts to minimize its devel iite timer set at, for example, 2 opment. Moniioring etivironment m|nutes out of ten, the five minute 31 rotations at bird level is the timer wduld be set at 1 minute out 61551 ste P m effectively eliminating of five. This'results in the same 0001 P°° r temperatures during amount of fan “on” time and the brooding, same fresh air exchange but the house environment benefits from more frequent air mixing and hence, less chance for temperature T at 5 off floor (avg 88) T at chick level (avg 84) T at chick level sidewall (81). . 6 00 12 00 Time on 12/10/97 Lancaster Fanning, Saturday, February 13, 1999-03 18 00 Lancaster Farming Check Out Our Site www.lancAsterfrnniiig.com
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