Switch to indirect heating improves bird performance for poultry farmer

One South West broiler producer is reaping the benefits of indirect heating through improved bird environment, less ventilation requirements and exceptional growth rates, as Aly Balsom reports

It took just one crop of birds for Robert Lanning to be convinced of the benefits of indirect heating and start planning for the system to be rolled out across his six broiler units.

After deciding to renovate a newly acquired poultry site with the latest technologies, Mr Lanning chose to step away from the traditional direct heating system used across his Devonshire Poultry business and trial an indirect system.

Whereas direct heaters pump the CO2 and water produced from combustion back into the shed, indirect heaters have a closed combustion system and remove these undesirable gases from the building. This not only reduces the need for shed ventilation – potentially reducing energy costs – but also helps create a better environment in which birds can thrive.

Since trialling two Winterwarm DXC Heaters at his site near Crewkerne, Mr Lanning has quickly seen improvements in shed atmosphere and daily live weight gains. This is coupled with the potential to reduce the farm’s carbon footprint in line with growing demands from the supermarkets he supplies.

“I was so pleased after one crop I bought two more heaters and cancelled the order I had placed for direct heaters,” says Mr Lanning, who farms in partnership with his wife Jacqui.

The system has now been used for two crops of birds, with Winterwarm originally financing two indirect heaters in one shed over a three-crop trial period, starting in May.

However, Mr Lanning has already chosen to invest in the system across the four sheds at Egwood Farm. The plan is to use this as a blueprint for the rest of the business, which produces 3.5 million chickens a year for 2 Sisters and Faccenda.

He says one of the most instantly noticeable benefits from using the new heating system has been a less humid and more pleasant atmosphere in the sheds.

“There’s a lot sweeter smell in the buildings and the straw bedding has a “crunchier” feel,” he comments. Birds are also a lot more evenly spread, indicating good consistency in temperature.

Bird performance

At Egwood, chicks arrive at a day old and are sent for processing from 33 days old, weighing about 1.8kg.

As a result of the improved environment, Mr Lanning has witnessed a marked improvement in bird performance.

“Daily liveweight gains have averaged between 63g and 64g/day on these two crops. I’d expect them to be in the late 50s, early 60s, so these are exceptional.”

And although you may expect chicks produced by younger parents to have lower growth rates, this was not the case for birds reared in the buildings with indirect heaters.

“If we look at the figures from the second crop, chicks produced from a 45-week-old parent achieved 194g to 206g at seven days when housed in the sheds with direct heaters.

“This compares with about 197 to 198g for chicks from parents that were 34 weeks old, in the sheds with indirect heaters. These are exceptionally good seven-day weights and that’s reflected in heavier kill weights.”

Improved air quality has also resulted in a reduction in ventilation requirements. When the chicks arrive, the indirect heated sheds have a lower average minimum ventilation level of 3%, compared with 8% in the direct heated sheds.

“This means heat is being kept inside, so we won’t need to use as much energy to maintain temperatures,” says Mr Lanning. “I’d be amazed if we didn’t see a saving in the cost of gas, but we need to get a winter crop through the system first.”

Mr Lanning says part of the attractiveness of the system, over a biomass boiler, was the fact it could be easily installed and required less capital.

“Where we could have put direct heaters, we just plugged the indirect ones in. The only addition was a flue,” he says.

At Egwood, two direct heaters have been retained in each shed to run alongside two indirect heaters. This means they are there as back up and can be run in tandem during cold winter periods.

How do the Winterwarm DXC indirect heaters work?

Fresh air is pulled in from outside the building down a flue. This mixes with gas and is burnt in the combustion chamber. Burnt air and gas is pushed through a network of burner tubes.

A fan sucks air from outside down and over the tubes to heat the air within the shed.

The carbon dioxide and water produced from combustion are pumped out of the building and do not enter the shed.