We have finally installed sun-blocking window film on FPB 78-1 Cochise, and the results are excellent.
Cochise was launched without window film. We knew that it would eventually be required, but wanted to get a handle on what level of protection would be appropriate after some real world cruising experience. Obviously the FPB 78s have a substantial expanse of glass, more than any other FPB to date (in scale), so there was never any question we would need some form of film. Even in New Zealand winter, during sea trials, we would routinely find it necessary to reduce heat load by dropping the cellular window coverings.
After much deliberation we chose EIR window film by V-Kool. This material uses silver particles embedded in the film to reflect the heat (as compared to the 3M ceramic films we have used in the past which block the heat). The negative is that the silver does attenuate cell phone and GPS signals. In the photo above, you can see the difference between the unfilmed window in the middle and the ones on either side, with the film added.
We used VK 40 on the side windows, VK70 on the forward windows, and nothing aft. The film was supplied and installed by V-Kool of Florida.
There are all sorts of numbers about light transmission, heat rejection, and selectivity. It is hard to know what these mean in the real world, but after a few weeks of experience here is what we can tell you:
- The film works so well that we did not have to use the cellular window shades to keep the boat cool in Southern Florida in early March.
- There is no problem seeing small boat lights when on watch looking forward at night.
- The reduced reflectivity is very helpful with the FPB 78 outward slanted windows at night. There is less glare from overhead lighting and instrumentation.
- Cell phone signal attenuation is definitely a factor. Signal strength showing four bars becomes two bars when inside the great room. The Matrix deck is less of an issue as the opening windows, doors, and aft enclosure do not have film.
During the day the window film also provides a touch of privacy. More important, we like the look of the darkened bands of glass.