Ensy Filters

Ensy is a Norwegian manufacturer, and the model label on its residential MVHR units, such as the AHU 300 series, is usually located near the service hatch or the filter compartment. If the label is missing or unreadable, the quickest way to find the right filter is to measure the length, width, and thickness of the current filter in millimetres and compare them with the dimensions listed in our catalogue. This method works reliably even when the exact model name can't be determined.

Most Ensy models, including the AHU 300, come with two filters in the same housing cavity:

• an F7-class filter for supply air
• an F7 or M5-class filter for extract air, depending on the model

For those wanting extra odour control, an activated carbon filter is available for some Ensy models. Before ordering, it's worth checking the exact filter class stated in your unit's user manual, as it can vary between AHU series variants.

Ensy MVHR user manuals are usually available on the manufacturer's website by specific model (e.g. the AHU 300 ceiling or floor-standing variant), and they specify the recommended filter check interval as well as what the control panel indicator means when it reminds you to change the filter. If you can't find the manual, or it's not in Lithuanian, follow the general rule of thumb – check the filters every 3 months and replace them sooner if you notice weaker airflow or increased noise.

The usual recommendation is to check Ensy filters every 3–6 months, and to replace them when the control panel shows a warning or you notice weaker airflow or a stronger smell indoors. During the cold season, when the MVHR unit works harder to recover heat, the filters can clog somewhat faster, so it's worth checking them earlier than your usual schedule in winter. For summer houses or rooms visited only occasionally, it's convenient to arrange repeat deliveries matching your usual replacement interval.

Compatible Ensy filters are made to the same F7/M5 filtration class and identical dimensions as the originals, so air cleaning efficiency and fit remain the same. The difference is essentially just price – original Ensy-branded filters are usually more expensive due to packaging and distribution through official dealers, while a compatible alternative lets you save money, especially if you replace filters several times a year. The main thing is to check that the alternative matches the exact dimensions and class for your specific AHU model.