Problems we solve – Heat gain study – The importance of calculating heat gain

Problems we solve – Heat gain study – The importance of calculating heat gain

The UK snack foods industry: some of the largest food processing halls we investigate at FSL, typically producing three to five tons of snack product per hour from enormous factories. Many are purpose-built but some have been adapted from other industries, all require ventilating air for their workforce.

Now move to food processing and insert a vegetable washing, peeling and slicing operation, add ovens and driers with automated frying lines at 160 -180 degrees centigrade followed by flavouring and final multilevel packaging areas. Before sealing the product into the packing line bags, consider the capsule of air with the product before encapsulation, it should be the cleanest air in the factory. To ensure this is the case, filter the air, prevent dust and particulates from machinery entering from the conveying operations overhead.

Questions about the air changes should be asked; at this point maybe, someone will remark that this depends how much heat must be removed from the building. The brave may even guess this figure, but whatever is decided upon, it could be a game changer for the factory. If there is a risk of getting it wrong, then surely the next step is to measure and provide a calculation summarising that figure of heat.

We admit, very few actually ask FSL or even hazard a guess as to what the heat gain from a large food factory might be. We know only too well this is dangerous territory and too risky to attempt.

On a recent European new build, inaccuracies in the assessments of heat gain caused the halting of the project, thankfully at early stages. The originally estimated number of air-handling units destined for the roof was doubled as a result. The steelwork dimensions dramatically increased in size, roof loadings were re-worked, costs spiralled upwards.

At this point FSL were invited to a review – the only strategy was to proceed carefully; re- address the heat gains, re view the hot processes, all of which were well known and understood by the factory team. Their knowledge proved to be vital and slowly information turned guesses into some science.

In summary the heat gain of a factory design is ‘truly in the detail’, it is your document that will enable the airflows to be calculated This is a key element of the tendering process and is able to assist with ‘levelling the field’ for the contractors estimating costs for the project.