placing ac iunit on subfloor with downflo

The dust passing the primary filter is still captured (by the HEPA), and thus avoids being returned to the occupied space. By placing them downstream of a primary collector, they can monitor dust loading in the return air and display an increase in pressure drop to alert the operator there is an apparent leak in the primary filter. HEPA and ASHRAE filters tend to show relatively rapid increases in pressure drop when they capture relatively small quantities of dust. A relatively common approach is the addition of HEPA or ASHRAE filters as monitoring filters between the collector and the exhaust back into the building. Many design practices recommend the system recirculating air into occupied spaces have monitoring systems in place to ensure the quality of the air returned to the space. This approach has the potential to be a great money saver if your facility suffers weather extremes, but you may need to evaluate some additional capital costs before you start returning air to the facility. This option is typically applied with high performance filter media to ensure effective particulate removal in order to allow recirculation. To prevent the loss of your heating or cooling investment, the decision may be made to return conditioned air back to the building after it has been processed through the collector.

This means that dumping conditioned air outside and replacing it increases the load on make-up air handlers and increases operating cost. That may be simple if you live in a temperate climate, but many plants have to invest energy and money to make their facility comfortable. Energy Savings – Discharged Air Has to Be ReplacedĪs a dust collection system operates, the air used to draw dust to the collector leaves a void behind that has to be filled with replacement air. While this approach may remain valid in some applications, current concerns with energy savings, combustible dust, and environmental regulatory compliance all suggest the prudence of additional consideration. This approach was employed whether collectors were located indoors or outside. Older dust collection systems employed a very simple approach to handling exhaust air from dust collectors just throw it outside into the atmosphere.

This article explains some of the opportunities and challenges for discharged air from filtration devices. As a result, system designers may overlook other factors such as what options to consider regarding the air leaving the collector. The attention in dust collection system design often focuses on the filtration device (collector). By Robert Walters, Donaldson Torit Regional Sales Engineer

Placing ac iunit on subfloor with downflo