NEC NC3200S and NC3240 Air Filter Replacement

NEC NC3200S and NC3240 Air Filter Replacement



The NEC NC-3200S and 3240S projectors, as shipped from the factory, used two different sized air filters.  The filter complement was as follows:
3 x NEC 80AF01 7"x7" filters in a row on the top to filter the incoming air cooling the lamp
2 x NEC 80AF01 3.5" x 9.5" filters used side by side on the front of the projector to cool the card cage
2 x NEC 80AF01 3.5" x 9.5" filters used individually on the non-operating side of the projector to provide cooling air for the light engine and ballast.

While the above filter complement works reasonably well, it leaves gaps between the air filters that allow dust to get through.  At Total Cinema Solutions we have modified this filter plan.  Instead of the two 3.5" x 9.5" filters side by side on the front of the projector, we substitute a single 7" x 9.5" filter.  Instead of three 7" x 7" filters forming a 7" x 21" filter area, we use a 7" x 14" and a 7" x 7" to provide coverage.  While this increases the number of different sizes of filter the venue must keep on hand, we feel that reducing the number of air gaps in the filter coverage is a major benefit.  Additionally, a single 7" x 14" or 7" x 9.5" filter is less expense than two of the smaller sizes that they replace.

Total Cinema Solutions provides an aftermarket air filter that is functionally identical to the original filters.  The part numbers are:
Filter Size
NEC Part Number
TCS Part Number
3.5" x 9.5"
NC-80AF02
NECFILTER3595AFTER
7" x 9.5"
Not Available
NECFILTER795AFTER
7" x 7"
NC-80AF01
NECFILTER77AFTER
7" x 14"
Not Available
NECFILTER147AFTER

The question of how often to replace the air filters comes up often and there is not a good, simple answer.  The official answer from NEC was as follows:
While this is a clean and simple answer, it does not take into account the environment that the projector is placed in.  One of the key factors in the longevity of a projector is its ability to dissipate heat.  Heat will cause the circuit boards, lamp and lamp ballast to fail more rapidly.  By extension then, keeping the air filters clean allows the projector to cool more efficiently.

Every projection environment is different.  Some projection rooms are clean as an operating theater, others are a dust bowl.  The best answer that we can give is to place a clean set of air filters in the projector and write the date with a marker on the white cardboard frame of the filter.  Check the filters monthly and, when they appear to be getting dirty, note the elapsed time and change them on that schedule.

The NEC Series 2 projectors (NC1200/NC2000/NC32xx) use two separate cooling systems; a high velocity/high volume system for cooling the lamp and a lower velocity/low volume system for cooling the electronics.  The result of this is that the air filters on the top get dirty in about 1/2 the time of the other ones.  A diligent operator could, in theory, end up with a schedule that replaces the top filters every 3 months and the other filters every 6 months.  This would provide the necessary replacement at a lower cost.  The downside is that it requires more attention from the operator in remembering to do it.  Given that the longevity of the projector is at stake, when in doubt, err on more frequent replacement than less.