The fifth-wheel RV that I use at my basecamp has sixteen 12-volt fluorescent fixtures, each containing two F15T8 tubes. Each fixture uses 30 watts (2.2 amps) of 12-volt power to produce an effective 1,100 lumens of white fluorescent light.
If all fixtures are turned ON at the same time, the wattage is 480 watts (40 amps) and produces a rated luminosity of 27,480 lumens. But because of the limited light efficiency of fluorescent fixtures, the fluorescents only provide an effective 17,600 lumens (1,100 lumens each).
Oh yes, since the electrical efficiency of the ballast and lights is only about 50%, they are pumping 240 of those watts into heating the air in my rig.
In my humble opinion, that is just too much lighting (and heating) for an RV, even a large one with 400 sq-ft of space.
My sixteen fluorescent fixtures are grouped into four sets of three each and four singles. By turning OFF two of the three fixtures in each group, we could reduce our consumption to 240 watts (20 amps), and still have an effective luminosity of 8,800 lumens. That helps, but the resultant lighting is lumpy: too bright in some sections and dim in other parts of the rig.
So that is still too much lighting for some of the space we live in, and too little elsewhere. The obvious solution is to switch to LEDs to replace the fluorescent -- and that is what I did.
When I switched to LEDs, I intentionally reduced the amount of light from each fixture by disconnecting the ballasts and installing a single MyT.fLED-12 LightStrip in each fixture. Each fixture now provides an effective 480 lumens of light each, so the total lighting is 7,680, nearly what I could get by turning off eight of the fluorescent fixtures. And the light is constant throughout the rig, just as we want it. At the same time I reduced the electrical load for lighting from 480 to 96 watts, (40 amps to 8 amps).
As an added bonus, on warm summer evenings I no longer have to use nearly 750 watts to power the air conditioner to remove the excess heat produced by the fluorescent fixtures with their inefficiencies. That can easily add up to an additional 3kwhr per evening, so I am saving 4.2kwhr per evening.
At a retail cost of $37.20 each, the cost of converting all sixteen fluorescent fixtures is less than $550 with the 10% quantity discount. I get better light without heat or fluorescent radio interference or having to replace fluorescent tubes. And it takes about 5 minutes to convert a fixture. LEDs are a win-win solution.
Sam Penny, the Prudent RVer