Egg Industry - May 2018 - 5
EggIndustry ❙ 5 A heat exchanger allows for the fresh cold air from outside the layer house to be preheated by the warm exhaust air. | Courtesy of Vencomatic issues this past winter, despite some very cold periods. The only negative observation they report since last fall has been an increase in dust inside the house on some warm days due to manure becoming even more dry than normal. Mrs. Van Vuuren mentioned, "The ammonia levels are much lower due to the lower humidity. Litter quality is much better with the Clima+ unit. The environment is much better for both the birds and workers." Vencomatic has installed several heat exchanger units in the U.S. and claims 80 percent thermal efficiency. Producers are encouraged by the company to combine the heat exchanger with a manure belt aeration system. Preheated by normally wasted heat from exhaust air, warm fresh air is piped to manure belts under an aviary system to dry manure while still in the house and provide fresh warm air to the birds. Air brought in from outside in the wintertime will have lower relative humidity than house air, so using heated outside air will dry the manure more quickly than house air will. As environmental contamination is becoming more closely scrutinized the heat exchanger incorporates filter systems to capture dust (particulate matter) from exhausted air reaching 80 percent efficiency. Supplemental heating Heat exchangers do not entirely eliminate the need for supplemental heat. Vencomatic employs a propane fired preheating unit to heat incoming air when temperatures fall below 15 F. May 2018 ❙ www.WATTAgNet.com Maarten Vlug, engineer, Jansen Poultry Equipment, notes that in Jansen's heat exchanger design, "With those low temperatures (under 5 F), we use a water or gas heater after the heat exchanger to get the temperature close to 64 F before the air enters the house. As for our heat exchanger, I would recommend installation inside the house with temperatures lower than -4 F or an external enclosure that is well insulated. At very low outside temperatures, the water supply will be shut off to prevent damage to the water or brush cleaning system." Dealing with dust One concern with heat exchanger technology has been the ongoing cleaning and maintenance required to keep systems from plugging or clogging up with dust. "Crossflow heat exchangers always have pulse jet air filters which are automatically cleaned by pulses of air. But the downside is that use of filters will create a high counter pressure, thus requiring stronger fans," noted Vlug. Jansen has an additional cleaning option that includes a patented automated brush system in combination with water flushing. Vencomatic has designed an automated flushing system which uses water to clean dust between the panels once a week. In warm weather, when supplemental heat is not needed, the heat exchanger can be bypassed to eliminate the need for cleaning the system. Payback period Victor van Wagenberg, product manager,