Here is a short study of LED lighting Vs. the original model#921 incandescent bulb supplied as standard equipment on my Fun Finder RV.
Referenced in the photo are - the #921 incandescent bulb which is standard equipment. Cost $0.65 each.
“larger LEDs” is an 18 segment LED lamp, Part number 921-252 Wedge base RV light. Item # 921-252 T10 base. Cost $15.85 each
“smaller LEDs” is an 15 segment LED lamp, 906 Wedge base reading light, Item # T10 base, 15 LED warm white. Cost $8.00 each
These were purchased from http://www.ledtrailerlights.com
. I always recommend shopping around.
Many online stores sell these same LED lamps and most have their own part number for the same item.
Overall illumination – The brightest of these is the 921 bulb. A very close second is the Larger LED lamp claiming to have 252 Lumens on one site and 160 Lumens on another. The smaller LED lamp claims to have 75 Lumens. As the composite of photos show the smaller LED is noticeably weaker than the other 2. In the LED industry there are brighter LED segments available. These are also much more expensive. A second reason for building lamps with many LED segments is due to the narrow direction each segment will emit its light. A tungsten filament will disperse light in all directions. LED lamps require several segments pointed in different directions to accomplish the same coverage. Hopefully the future price of these brighter LED segments will go down as demand rises.
Physical fit – The larger LED is larger is 1” in diameter and a bit longer than the 921 bulb. Still I was able to use it in every fixture including one with a narrow glass lamp shade. The smaller LED is about the same size as the 921 bulb. I also received a flat panel of LEDs with a wedge plug that allows it to fit right in place of the 921. The flat panel LED arrays are no better than the round lamps. The one I chose has 15 segments, cost $18.00 each. This emitted the same amount of light as the small LEDs written about here. Similarly I would expect a flat panel LED array with 18 segments to be as bright as the large LEDs. The flat panel layout did not seem to add to the brightness of the lamp.
Color - You may have never thought about it but every light source has its own color, usually referenced by a Kelvin number. Noonday sun is about 5000K, Fluorescent lamps can vary from 3200K to 7500K, Cool white is about 3500K, Warm white is about 3100K, Household Tungsten lamps are typically 2500K – 2900K. The LED lamps I purchased were all advertised as warm white 3150K. Even so, the camera shows a wide difference in color rendition between these 3 sample lamps. In reality our eyes are more forgiving. Personally I could not discern much difference in color between these samples. I have worked with the bright white (5000K-6000K) LEDs and they will change the colors you see. The higher Kelvin value in lighting will also fool your eyes making objects appear brighter.
Energy draw – The only good reason to spend high dollars on replacement lighting is higher efficiency. This translates directly to longer battery life. My new 19 foot trailer has 18 light bulbs. Each one is the model 921 wedge type bulb. Each bulb draws 1.3amps Vs the larger LED lamp which draws only .2 amps and the smaller LED lamp which draws .11 amps. That’s a huge savings in energy translating into longer battery life or longer poker games. I took these measurements myself using the lamps I purchased with the trailers 12 volt battery simulating real world conditions.
Cost – At this point in time you get what you pay for. The larger LED lamp runs $15.85 to $21.00. The smaller LED lamp is about $8.00 to $12.00. If I replace ˝ of my fixtures with LED lamps 9X$16.00=$144.00. Putting this in terms of battery life. I would need to purchase 5 more batteries to have the same Tungsten Light Hours as enjoyed by upgrading to LED lamps.
So I have chosen to upgrade the most commonly used light fixtures. I placed the smaller LED lamps over the sink where I am lighting a smaller area and the light fixture is closer to the work area. Over the dinette, in the bath, and the centrally located ceiling fixture I have installed the larger LED lamps. My other light fixtures are used very little so the energy savings may not be worth the expense. I have also upgraded the patio light. The wife and I like to walk around after dark and it’s nice to have this amber light showing us the way home.