Air filter condition monitoring increases service life

After John Morfield Ltd was awarded a contract to supply filters to a leading food manufacturer they committed to investigate potential areas for significant ongoing cost savings.

One key area identified was the provision of clean HVAC air to the food preparation area where it was established that the original setup of high quality pleated pre filter panels and rigid bag secondary filters were being changed by the customer on a 3 monthly time based cycle as part of their planned maintenance procedure. After conducting a site assessment John Morfield engineers suggested that the filters were being changed prematurely and that significant increase in service life would result if change was based on filter condition using magnehelic gauges to monitor the filter pressure drop.

A controlled trial protocol was agreed where John Morfield service team would fit a brand new set of filters and periodically monitor their condition. The results were that the service life of the pre-filter panels was established to be six months and the rigid secondary filters 12 months. At the same time that the trial was running a second trial was requested by the customer.

This exercise involved fitting an identical HVAC system with a set of filters from an alternative manufacturer who was offering filters to the same technical specification but with significantly reduced surface area and cost saving of around 20%. This trial was conducted under the same protocol and over the identical timeframe and proved that the original filters achieved double the service life to that of the alternative filters.

The savings in terms of filter costs and manpower to change these filters alone just by reverting from time based changes to condition based is in the region of £10,000 per year even using the “more expensive” filters which in turn bring other benefits such as better and more consistent down-stream air quality, and savings in disposal costs.

Once the trial was completed it was agreed that a service contract be initiated to sup-ply, fit and monitor the filters with two vis-its per year, once to change all filters, once to change the pre filter panels and a monthly visit to monitor the blockage indicators.