9.4. FANS
• Every three months, clean the dirt from the fan blades and bearings, since dirt can not only
reduce airflow but also lead to unbalanced operation and increase noise.
• Periodically, test the airflow on each fan.
9.5. FILTERS
• To make sure that the filters are working properly, the pressure loss across the filter must
be monitored precisely (since this is an indicator of dirt levels). The following table indicates
the maximum recommended values for pressure loss before filter replacement.
Filter
Pressure
Loss (Pa)
• Even if the maximum pressure loss has not been reached, filters should be inspected each
month to make sure that the filter and filter housing are sealed.
• It is not recommended that filters be washed, since they will never recover their initial effi-
ciency and doing so can produce wear on the filters. Although washing or vacuuming in
the opposite direction from normal air circulation can achieve an optimal finish, it is recom-
mended that you always have a set of replacement filters on hand. Under no circumstances
should the unit be run without filters, since this can introduce dirt into vital components of
the unit and lead to equipment wear and loss of efficiency.
9.5.1. REPLACING THE FILTER IN THE MAIN UNIT AND SIDE-BY-SIDE
OR STACKED RECOVERY UNIT.
To remove the filter, open the inspection door, and remove the filter by pulling it out. For the
high efficiency filters (F7 to F9), an easy fixing system is used to assure higher tightness. Turn
handle and remove the filter. This system is found on the filter modules and side-by-side or
stacked heat recovery modules too.
G4
F5
150
200
F6
F7
200
200
47
F8
F9
225
225