I am in the process of replacing my incandescent bulbs with more efficient alternatives. My home is about 14 years old, I've owned it for a little over three years. It seems most of the bulbs that it "came with" are original, and since I purchased the house almost every tungsten bulb in a built-in fixture ended up burning out. In particular were the R40 ceiling floods, of which I have 16 in total in the interior. I'd ignored many of them, as I rarely turned most of them on, however when three in my kitchen burned out within a weeks period, I up and replaced the whole lot with EcoSmart (made by Lighting Science) R30 CFL's that offer around 800 lumens.
The initial difference was HUGE. The 14 year old bulbs were extremely dim and VERY orange in color. The CFLs, when fully warmed up, are very nice and bright. I chose cooler colors (3500k and 5000k) which light the place much more naturally (at least to my eyes). The caveat with CFL, as I am learning, is they do not perform well in cooler temperatures. I try to use my heater as little as possible in the winter, generally only heating when the interior temperature drops below 60-64 degrees. All of the CFL R30s I purchased have a common problem, which seems to be common across brands as I've tried TCP, Phillips, and others: Very long warmup time, very low lumens during warmup, and an extreme magenta hue during warmup. The bulbs also do not seem to reach full brightness, and the way the reflectors are designed, the shape of the spiral inside the R30 "can" is clearly visible and appears rather dark.
I've decided to switch to LED, despite the cost. In trying out a few from the local store, they seem far superior to CFL. They start instantly, always produce the same color, are fully dimmable (and seem to dim smoothly unlike CFL), and don't seem to be affected by temperature. I've only ever used R or BR type, however all of the ones at the local store in the color temperatures I prefer are PAR type. The BR type LED floods seem to produce similar quality and diffused light to the CFL's, but the only color I can find are 2700K. What exactly is the difference between an R/BR type flood and a PAR type flood? Additionally, what are the differences between PAR30, PAR38, etc? Are PAR type good for indoor use (in the past, I'd only ever seen a few mentions that PAR type were required for outdoor scenarios, indicating they were better sealed against weather)?
Best Answer
Due to the lack of adequate answers, I decided to research the differences myself and provide an answer to the benefit of the community.
PAR Type Lamps
From a build quality and light control standpoint, PAR type lamps are generally considered superior. The explicit parabolic nature of the reflector means light is more precisely reflected directly out of the bulb cavity, with less dispersion, than an R or BR type lens. PAR type lamps, thanks to the design of the lens in front of the actual light emitting element (which is usually a given with home lighting...PAR in general can referr to a very wide variety of lighting which may or may not have a front lens, including high powered stage lighting). The lens is often fresnel in nature, are often additionally capable of focusing the more accurately reflected light into a brighter, narrower spot. The fact that they have a more precisely crafted lens means they are capable of being designed to emit beams of varying angular degrees wide (anywhere from 12° to 70°), with high intensity narrow beams or more diffuse wider beams, makes them highly flexible.
PAR type lamps are also frequently designed in such a way that makes them viable for outdoor use. Not all PAR type lamps are properly sealed for use in humid climates or areas where rain or other water could intrude upon the bulb, but many PAR type lamps are. This is a key difference between PAR and R or BR type lamps.
In terms of nomenclature, PAR lamps are usually designated with a number. The number of a PAR lamp, such as PAR38, gives the diameter of the lamp in inches. In the case of a PAR38, the diameter would be 4.75" (4 3/4"), or "thirty eight eighths of an inch." Common PAR lamp sizes for home are PAR20, PAR30, PAR38, with the latter being most common.
R Type Lamps
One of the more common types of flood light lamps for use indoors, the R-type lamp is a more cheaply constructed "reflector" type lamp. They are not particularly efficient in any key respect, their design is roughly defined and there are no strict rules or guidelines regarding the reflector. As such, R-type lamps generally produce a highly diffuse light with a broad angle.
They use a similar nomenclature as PAR type bulbs. For example, an R40 is a bulb 40/8ths of an inch in diameter, or 5". The two most common R-type lamp sizes are R40 and R30.
BR Type Lamps
Preceding the CFL and LED age of high efficiency lighting, the BR-type lamp was an attempt to produce a more efficient indoor-use only replacement for R-type lamps. Standing for "bulbous reflector", the design of a BR-type lamp is more strict. The reflector is designed in such a way as to more efficiently reflect light. They still produce fairly soft, diffuse light, however it is reflected in a narrower beam, thus more efficiently utilizing light produced by the internal emitter (filament, LED, or CFL spiral.)
They too use the same eighth-inch nomenclature as PAR and R type lamps. The most common sizes are BR40 and BR30.
CFL and LED R, BR, and PAR type lamps
While the core design of these types of lamps was implemented in the days of tungsten-filament (incandescent and halogen) bulbs, the design is still used for CFL and LED lamps. In the case of CFLs, the actual reflector efficiency is likely suspect (at least in the case of a PAR type lamp), as the design of a PAR lamp, and thus it's efficiency in utilizing light, is dependent on the size and location of the internal emitters. CFL spirals are usually used in CFL-based flood lamps, and CFL spirals are a very different kind of emitter than a filament or LED. LED based flood lamps probably resemble classic filament based flood lamps better than CFLs do.
LED and CFL Light Quality
In some experimentation of my own, LED-based PAR type lamps definitely seem to direct a far greater quantity of their light downward, where as CFL spiral-based lamps still generally produce a more diffused output. Depending on the type of lens in front of the emitter, the quality and shape of the projected light for both CFL and LED PAR type lamps can vary greatly, from caustic refraction to fairly diffuse. CFL R/BR type lamps nicely simulate their incandescent predecessors. LED R/BR type lamps do not seem to diffuse quite as well as CFLs, so if you are looking for diffuse flood lighting, CFL generally has a more pleasing diffusion.
LED PAR lamps definitely produce a greater amount of directed illumination, so if you need to brightly light anything, LED is probably the best choice. LED flood lamps are also usually fully dimmable, "instant" on (sometimes "instant" really means up to a half-second delay before light is actually emitted), and produce far greater consistency of color (CFL color consistency is often rather poor, and during cooler or cold days, CFL floods will frequently brighten, dim to a deep magenta, then slowly normalize as they warm). LED lamps, of all designs, are usually fully dimmable these days as well. Dimmable LED flood lamps are usually dimmable down to 10% illumination, with some from the better manufacturers (such as Lighting Science) often dimmable down to 5%. Dimming quality, smoothness, minimum output and consistency is vastly superior on LED compared to CFL, with no flicker, popping, blinking, or inconsistent dropout as is frequent with dimmable CFL lamps.
In terms of the quality of projected light, BR-type CFL lamps definitely produce a smoothly diffuse light with little visible pattern directly underneath each bulb. PAR type lamps, either CFL or LED, but more so in the case of LED, produce visible refraction patterns under each bulb. I believe this has a lot to do with the design of the lens, and when multiple flood lamps are used along a hall or in a kitchen, diffusion improves. LED PAR type lamps can be very bright, which is nice when you need light.
My Choice and Recommendation
I have chosen to refurnish my kitchen, and eventually my hallways, with Lighting Science 5000k and 3000k (or possibly 4000k) Dimmable PAR38 LED lamps. These puppies are about $34 each, however they have twice the lifetime rating of comparable lamps from all other manufacturers (50,000 hours @ 6hrs per day vs. 25,000 hours @3-6hrs per day). The light is not as diffuse as your standard R-type incandescent, but the color quality is far superior for those who have never much liked the deep orange color of a classic incandescent (the 3000k versions are closer to a halogen in color, and the 5000k produce a nice, clean, crisp neutral white.)
For the highest quality, I recommend the following. Since LED lamps are dimmable, it is recommended to use a dimming switch wherever you use high lumen LED PAR lamps (i.e. 800 lumen or brighter). Personally I use Lutron HED-certified digital dimmers with dimming setting memory. One push of the button and the lights fade up over about a 1.5 seconds to your pre-set brightness level. Another push of the button, and the lights fade to minimum brightness then off over several seconds. With 800 lumen bulbs, setting a Lutron digital dimmer one or two notches down from maximum brightness produces very pleasing illumination, with the added bonus that if you need more light, or wish to add light during the daytime to fully illuminate areas that might generally be in shadow, you have the ability to crank up the illumination beyond that pleasing level.