Retrofit Solutions

Existing air-handling units rarely have enough space to accommodate our components. But we have designed variations of our gas-phase solutions to work under such circumstances. Sometimes we use ProGuard^® Filters to replace common particulate filters with our combination particle filter with gas-phase media throughout the filter. If the level of pollution is not severe, this is a quick, simple, and easy solution. For greater challenges, we can provide a separate scrubber that sits near the air-handing unit, one that has its own fan and prefilters paired with the gas-phase media either in modules or within a deep-bed scrubber. We build them to sit inside a building, on a roof, or somewhere in the duct ahead of the air-handling unit so that all the return and ventilation air is cleaned prior to conditioning.

We optimize each of our solutions for maximum media life and compatibility with its surroundings at site. Example – Side stream: A scrubber sized to treat 20 to 25 percent of the full airflow, our side-stream unit sits beside the air-handling unit. It taps into the return duct, purifies the air, and then blows it into the duct just ahead of the air-handling unit. Over time, this approach reduces the amount of pollution in the building, creating a healthier, cleaner, more productive environment. Example – Partial Bypass When there is sufficient depth ahead of the fan and cooling coil, we can install a track, with low resistance and 2” bed depth to support our gas-phase modules. This is a better solution that provides more media. So it lasts longer and does a good job ridding the air of odors and/or corrosive gases. By not filling the entire housing with modules, we enable air to bypass it, thus not adding significant resistance to the airflow. When fan capabilities are maxed out, this is a good alternative to adding a full gas-phase media stage.

Example – PMA Retro The PMA Retro was designed to directly replace any filter with a 1 inch header in a filter housing so gas-phase solutions could be added. An older AHU with prefilters might have a 12 inch deep stage used for a high efficiency filter. If the need arises to remove odors and gases, the PMA Retro can replace that filter making it possible to have a gas-phase media in sufficient quantity to handle more than just nuisance levels of gases. An example is a museum that was down stream of a paper mill that need to remove the sulfur gases to protect its art works.