October 15, 2010

Higher air scrubbers reduce odour in pig houses

Increasing the stack height of pig-house air scrubbers reduces the odour nuisance to the surroundings: this means of limiting odour levels can offer pig farms an interesting and economical alternative.

This has been demonstrated in a study carried out by Wageningen UR Livestock Research which was financed by the Product Board for Livestock and Meat (PVV).

Model calculations were carried out to explore the effectiveness of switching odour-reduction plants on or off on the basis of the prevailing wind speed. Using these systems only when required results in low odour levels (of almost the same levels emitted from air scrubbers operated continuously) at considerably lower costs.

The study explored technical options for the reduction of odour hindrance from pig houses. The researchers compared the following technical options for the reduction of odour levels: air scrubbers, increasing the stack height, diluting pig-house air exhausted from air scrubbers and a series-connected emission-reduction technique.

They used an odour distribution model to calculate odour levels attained with the continuous operation of the various technical options. Air scrubbers with an increased stack height (15 metres above the ground) offered the best price-quality ratio.

Model calculations were also carried out to explore the effectiveness of switching odour-reduction plants on at low wind speeds and off at higher wind speeds. This can offer a solution in the most extreme odour-nuisance situations, such as sultry evenings.

Operating an air scrubber solely when air speeds were lower than three-metres per second achieved almost the same odour level obtained with an air scrubber that is operated continuously, while the operating hours were almost halved and the costs (in particular, electricity) were substantially lower. Switching on more expensive technical measures solely to reduce peak odour levels is appealing to pig farmers and their surroundings.