Hitachi RAC-25RPA Instruction Manual page 35

5. AIR CLEANSING FILTERS (SPX-CFH15)
When installing the air cleansing filters, remove the air filters and attach
Air cleansing filters
them onto the hooks of the front cover frame.
The cooling capacity is slightly weakened and the cooling speed becomes
slower when the air cleansing filters are used. So, set the fan speed to
"HIGH" when using it in this condition.
The air cleansing filters can be used for 2 years.
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