Thermac M Series Moisture Filter for NPU

Item in Stock   |   Usually dispatched within 24 hours

The Thermac NPU Moisture Filter has been designed to help protect both the primary filter and the HEPA filter within a Negative Pressure Unit (NPU), when used within wet blasting environments in the asbestos industry.  

The Moisture Filter prolongs the life of the NPU by preventing moisture entering the pre-filter and the unit itself. This protects the integral workings of the NPU and delivers cost-savings by reducing the quantity of pre-filters required on a daily basis, when operating a NPU in a wet environment. It also prevents premature damage to the HEPA filter.  

Key Features 

The NPU Moisture Filter consists of two sections. The first incorporates Thermac’s unique filter technology which separates the water vapour from the air being drawn through the Negative Pressure Unit. This prolongs the life of the pre-filter and ensures the NPU runs at maximum efficiency in a moisture-rich environment.  

The second section houses the pre-filters, the first is a Type 90 Glass Fibre filter and the second a G4 Pre-Filter. This features an easy access opening so that the pre-filters can be replaced as and when required.  

The Moisture Filter also comes with a 17-litre removable drip tray with carry handles, to facilitate disposal of the collected water. A blanking plate is also supplied to protect the filter face when in transit.  

The Moisture Filter is securely attached to the front of the NPU with the integrated magnetic fixing system.  


The NPU Moisture Filter features specially designed polypropylene, vane-type separators in the first section which change the airflow of the moist air stream. The droplets of moisture are collected by the separators and then filtered through a series of drain holes into a drip tray positioned at the underside of the unit, ready for disposal.  


The Moisture Filter unit must be attached to the front of the NPU within the working enclosure. The Moisture Filter’s magnetic fixing system ensures an airtight seal is achieved with the NPU. An access panel allows the pre-filters to be replaced without removing the Moisture Filter. The contaminated water collected in the drip tray can be disposed of as per the applicable regulations.  

Hire Only 

Thermac’s Moisture filters are available to hire only. 


Please contact us for more information.