Novel dry heating system lifts poultry performance

A new heating and ventilation system is paying dividends at Alan Simpson Farming, as Ken Randall discovers

As one of the UK’s leading broiler growers, Alan Simpson Farming has always believed in developing its own solutions to problems.

With 15 broiler sheds near Whitchurch in Shropshire and a capacity of over half a million birds, the family has traditionally sought better ways of doing things.

In the past they have pioneered their own chick dispensing machine, a feed depositor that lays tracks of paper in readiness for chick arrival and a machine for searing the shed floor.

It is probably no surprise, then, that the Simpsons have taken full advantage of the Renewable Heat Incentive (RHI) to install biomass boilers across the farm.

To make the best use of this heat source, Charles Simpson opted to install hot water radiators in destratification fan boxes mounted in the roof apex.

Put simply, these units employ a hot water radiator mounted horizontally under a down-blowing fan. Directly underneath the radiator is a baffle box with adjustable deflector plates, which directs the airflow around the shed to achieve a uniform heat profile and bring the warm air into contact with the birds on the floor.

The Simpsons were already using the destratification fans in conjunction with conventional gas heaters before the biomass boilers and radiators went in, and had been impressed with the results.

It was at this stage, however, that Mr Simpson decided to take things a step further by developing his own radiator in conjunction with equipment manufacturer Hydor.

Two types of heater coil were available: a stainless steel version, which was strong but expensive; or an aluminium one.

“The trouble with aluminium is that you’ve got to treat it with kid gloves when it comes to clean out,” explains Hydor’s Duncan Burl. “If you don’t watch over the cleaning team, they can flatten the coil with the washers, and then you can’t get any air through it.”

Mr Simpson wanted something more robust. Working through another company that had helped create an earlier heating system, they developed a coil made from steel, which is first fully fabricated and then galvanised for durability. “These things are bomb proof,” he says.

The galvanised coils add about 6% to cost compared with the aluminium version – around £6,000 on a £100,000 package per shed. They are now available as standard from Hydor.


Mr Simpson believes the investment, which has totalled around £1.3m across all 15 sheds, should pay for itself in three years. There are a total of 11 biomass boilers serving the unit, rated at 199kW each, and come in “plug and play” form, ready-installed in shipping containers from Patchwork Energy.

Savings in fuel cost of the wood pellets over gas are around 30%, and the RHI is worth about £22,500 a boiler a year. Another advantage is that the sheds are running at 30C for brooding, whereas in the past they ran at 32C.

“It also feels cooler because you are not putting moisture into air by burning gas. The stockman in you would say at first ‘it’s not hot enough in here’. The higher the humidity, the warmer it feels.”

However, the biggest advantage with hot water heating is the lack of carbon dioxide, he believes.

“CO2 is such a big factor in the rearing of poultry. With this system you get a massive performance benefit, which people don’t always take into account when doing the sums. “

Bird performance has improved noticeably, achieving 400+ EPEF in several sheds over the last three crops.


Mr Simpson also emphasises the importance of the controls that are part of the package.

“To make it work you need a three-way valve, like a solenoid valve, so when the heating isn’t running flat out, there’s a constant trickle of a pre-set percentage of hot water, so there’s permanently a flow of warm air going into the shed.

“Fan speed is also reduced, and you can vary that. The system goes flat out when the shed is calling for heat, and then you set how much heat and fan you want going. You’re only ventilating for the birds’ needs, so you’re saving on energy consumption. It’s also good for the boiler to keep ticking over, rather than switching on and off.”

Mr Simpson finds that heating the shed from start, before the birds come in, has been relatively quick. “It gets up from, say, 10-28C in about six hours.”

He also puts some of his 400 EPEF results down to the water treatment programme he has been running in some of the sheds over the past six months.

“We have been doing some work with a company from Shrewsbury called LMS (Liquid Mineral Services), to provide clean water to our birds. The most notable benefit I believe is the decrease in FCR, where I typically see three to four points benefit from the sheds running the system.”

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