Volume 23, number 1, february 2009

Infrared for more productive agriculture

Agriculture is an important engine of the Québec economy. Livestock production sales in Québec reached $3.8 billion in 2006.1 At the time, these sales represented 62% of total agricultural sales. Different means of heating space with natural gas can result in operational savings and assist the produc-tivity of this major sector for Québec.2

The poultry sector includes different types of bird production: chickens, turkeys, quails, guinea fowl, etc.  They are also distinguished by the type of end product: meat (broiler, roaster, grain-fed), table eggs, hatching eggs. Broiler production is the most important in terms of the number of farm businesses and flock size.

Thus, sales from the poultry sector totalled $575 million in 2006. Of this amount, 72% came from chicken production. The remaining 28% is attributed to sales of turkeys, table eggs and hatching eggs.

From the energy consumption standpoint, space heating represents the biggest expenditure by far, followed by lighting and ventilation. Producers must heat and ventilate all year round to ensure the comfort of their livestock and obtain good growth. Ventilation is necessary to discharge the ammonia vapours generated by droppings, general aeration of the building and discharge of combustion products in some cases.

When one-day-old chicks arrive on the farm, the indoor ambient temperature must be 32°C. Moreover, this temperature is reduced gradually as the chicks grow. Adequate temperature control ensures optimum growth and food conversion.

Brooders

Traditionally, Québec producers make more use of brooders (Figure 1). The combustion products released directly into the ambient air increase the CO2 and humidity level when they are used. According to some producers, brooders are inefficient and have a limited life cycle because they are very sensitive to the dust constantly present in the hen houses due to the agitated activity of the chickens in the wood chips. The slightest draft extinguishers the burner flame, causing reliability problems. Electric radiant heating systems are sometimes used but necessitate just as much maintenance and remain expensive to operate.

 

Figure 1: Brooder

Figure 2: Low-intensity radiant tube

Infrared

It is found that infrared heating equipment (low or high intensity) is used very widely in Ontario; the situation in Québec is completely different. The valorization of this equipment in the Québec agricultural sector thus represents a major challenge. Currently, heating equipment often is selected according to the availability of the products offered at the retailer, who keeps units in stock that the producers “traditionally„ buy. The high acquisition costs of infrared units make them uncompetitive at first glance. This cycle must be broken. In fact, this type of equipment has many operational advantages.

Thanks to Ontario experience, the manufacturers must review the promotion of their products in Québec and now offer products adapted to the specific context of the poultry sector.

Experience shows that low-intensity radiant tubes (Figure 2) are a choice alternative in some agricultural sectors, such as hen houses. Thus, low-intensity infrared radiation technology generally suits well-insulated buildings with low ceilings, where the drafts are limited. Their radiation efficiency exceeds 40%. They have the advantage that they can be supplied directly with outdoor air for combustion. Moreover, the combustion products can be discharged outside the building, thus reducing the ventilation needs and the negative effects of these discharges on the ambient air.

Table 1 – Comparison of the radiation efficiency of different technologies

  Convection brooder Radiation brooder Radiant panel (high-intensity) Radiant tube (low-intensity)
Radiation efficiency 25-30% 35-40% 55%
and over
40-45%

Table 2 – Advantages and disadvantages of various technologies

Natural gas brooder Natural gas radiant tube
Advantages Advantages
  • low cost of purchase
  • simple technology that can be maintained by the farmer
  • combustion products discharge outdoors
  • stable combustion (sealed burners)
  • no manuel adjustement required
  • better radiation efficiency than brooders
  • uses outdoor air
  • reduced diseases propagation risks
  • longer equipment life cycle
Disadvantages Disadvantages
  • necessitates a lot of maintenance
  • unstable combustion
  • manual height adjustment (floor temperature)
  • low radiation efficiency
  • combustion products released in the building
  • uses ambiant air
  • shorter equipment life cycle
  • more costly to purchase
  • more costly to install (discharge ducts and evacuation air)
  • maintenance must be subcontracted

This technology has several advantages:

  • It allows outdoor discharge of the combustion products, which reduces the humidity absorbed by the wood chips and thus the risks of propagation of diseases.
  • It allows adjustment of the indoor temperature to the needs of the moment.
  • It eliminates handling, because the height does not have to be adjusted to keep pace with the birds’ growth.
  • It eliminates the risks represented by a bare flame at the same levels as the chickens.
  • According to all manufacturers, it increases farm productivity by improving the birds’ comfort. In this environment, poultry who have suffered less stress produce better quality flesh and a better grade at the slaughter plant.

The operation costs of use of radiant tubes are lower than those of brooders because their infrared radiation efficiency is higher. The tubes have an efficiency of about 40%, while brooder efficiency is estimated at 25%. To supply the same quantity of infrared radiation, the radiant tubes would consume 38% less fuel. This assumption implies that the operating mode of the two types of equipment is similar (floor temperature, ventilation, etc.). Moreover, by operating the radiant tubes on natural gas instead of on propane, the customer obtains additional savings due to the rate differences and benefits from a continuous supply thanks to a weather-protected underground network.

Replacement of the brooders with natural gas radiant tubes would generate nearly $3,000 per year of savings for a typical producer, not counting the savings that could come from greater productivity related to reduced mortality and better poultry grading at the slaughter plant.

Marie-Joëlle Lainé, Eng.
Technical Advisor
DATECH Group

Marc Beauchemin, Eng., CEM
Technical Advisor
DATECH Group

1.  Ministère de l’Agriculture, des Pêcheries et de l’Alimentation du Québec, Recettes monétaires agricoles 1999-2006.

2. This article is based on a technical review of agricultural production equipment (Revue technique des équipements de production agricole) produced by the Natural Gas Technologies Centre (NGTC) in August 2003.