619-777-6LED (6533)
  Leading Edge Designs
  • Home
  • Welcome to LED
    • About LED Lighting Company
  • LED Install Photos
    • Auto dealer LED Retrofit
    • Parking lot retrofit
    • Office retrofit
    • Warehouse Retrofit
    • Custom installations >
      • Custom LED Wall Sconce
      • Custom hospital food prep
      • Custom Auditorium & Church
  • Catalog
    • Universal Luminaire
    • Retrofit Street
    • Plate Series
    • Universal Round
    • Universal Round Plate
    • High Bay
    • LED Tubes
    • Can Lights
  • FAQ
    • LED Terminology
  • Contact Us
    • Guest Register
  • Blog

PAR20 or R20 - what's the difference?

7/10/2014

12 Comments

 
There are so many letters and numbers in the lighting industry, from types of lights to types of bases (that is the way the light connects to the power source), and it seems that every set of letters and numbers refers to a different thing.  I reviewed much of this in a recent post that you can see here, but today I am just sharing an answer to a question I was recently asked: "So, what's the difference between a PAR20 light/bulb and an R20 light/bulb, anyway?" Let's take a look at the similarities and differences.
PAR20
For starters, let's define what a PAR20 bulb is and what this tells you.  This is a relatively small bulb that measures about 2.5 inches at its widest point (across the face).  This is where the "20" in the name is derived.  It stands for 20 eighths of an inch, since this is how bulbs are historically measured in the United States.  The P-A-R part of the name stands for Parabolic Aluminized Reflector, which is a type of reflective coating on the interior of the light that is typically used to focus or channel the light.  This is often used as a spotlight or to highlight a particular area where it is desirable to project a fairly crisp outer edge to the light. 
PAR20 - More focus
R20 - Better Diffusion
R20
In contrast, let's take a brief look at an R20 light.  As you might expect from the PAR20 description, there are a lot of similarities between these two lights.  For starters, the number "20" again refers to the diameter of the light, which is 2.5 inches (20 eighths of an inch).  Additionally, the R stands for Reflector, meaning that the light is again channeled forward, but instead of creating a crisp outer edge, a diffuser ensure that the light does not have a crisp of an outer edge and are therefore better for more general lighting where diffusion is desired, rather than a focused area of light.  There are many different types of reflectors that make the shape of the light different, including blown, bulged, elliptical, and double, with each typically represented by the first letter and then an "R" (i.e. BR, ER, etc.), with a Blown Reflector being just an "R."

Similarities
Both bulbs have the same diameter and also typically have the same standard Edison Base, as shown in the pictures.  There can be several different types of light source typically used in a PAR20 or R20 form factor including incandescent, halogen, and LED, which is why the reflective nature of the bulb is still of great use, since the incandescent and halogen bulbs emit light in all directions.  However, as LEDs become more prevalent, it will be interesting to see if these same terms continue to be used, since LEDs have more directional light and may not need the same shapes and coatings to generate the desired focusing effect.  I recently wrote about this and many of the other advantages to LED lighting that can be found here.  

Either way, the bottom line is that a PAR20 and R20 bulb are the same size and can be used in similar situations, but the PAR20 will be better when more focused light is desired and an R20 will be better for more diffused light and general lighting situations.  
12 Comments
Dino Cera
1/11/2017 02:13:25 pm

Great write up, really appreciate the insight, and clearly defined descriptions. As a diy'er i had no idea and almost made a costly mistake.

Reply
Renee West
2/15/2018 01:36:52 pm

Thank you very much for taking the time to write this up. It is exactly what I needed to know and it's written very well.

Reply
steve g
6/17/2018 02:14:19 pm

My experieince is that R20 bulbs are longer and stick out of fixtures where a PAR20 bulb remains recessed.

Reply
mike
9/10/2018 12:17:56 pm

THANKS for description.

Reply
Clare Bray link
12/14/2020 07:40:20 pm

This waas lovely to read

Reply
S Tam
5/7/2021 11:30:24 am

Thanks for your excellent write up. It does help me understand the differences between R20 & PAR20.

Reply
lightbulbsizes link
7/9/2022 05:38:47 am

Great content, it will help me in my business Thank you for sharing useful information. Respectfully, David, author of the blog https://lightbulbsizes.com/

Reply
Ajay link
8/17/2022 05:40:13 am

Thanks for sharing informative article, I really like this post.

Reply
craig m hirsch
12/20/2022 03:17:24 pm

I'd seen BR type reflector bulbs in the past , they're not very common, I noticed the face radius is different than the R type bulbs and also that the Par types have a radius that's even less.than both the R & the PAR types The " B " in " BR " stands for " BLOWN " is that indictive of the manufacturing technique ? As in " blown glass " ?
What about the light beam of a BR type bulb how is it different than the other two ?

Reply
Sohail link
5/19/2023 04:45:16 am

Thanks for sharing informative article.

Reply
Outpatient Mental Health Atlanta link
12/11/2023 04:27:35 am

I found the information provided in this post to be highly relevant and current, making it a valuable resource for industry professionals.

Reply
mental health facility atlanta link
3/26/2025 11:56:06 pm

Our mental health facility in Atlanta is a safe and supportive environment designed for healing. We offer inpatient and outpatient programs tailored to your needs.

Reply



Leave a Reply.

    Archives

    August 2014
    July 2014
    May 2014
    January 2014
    December 2013
    October 2013
    September 2013
    August 2013
    July 2013
    May 2013
    April 2013

    Categories

    All
    Cost Savings
    Energy Efficient
    Energy Savings
    Heat
    Incandescent
    Led Health
    LED Qualities
    Led Technology
    Lighting Industry
    Savings Factors
    Savings Questions
    Solid State Light
    Value Increase

    Recent Posts
    LED lights cost more, or do they?
    Well, it depends
    How can 10,000 lumens be brighter than 20,000 lumens?
    What are some of the health benefits of LED lights?
    How do LED lights save you money?
    Why do LED lights use less energy?

    RSS Feed

    Author

    Bill Motsko is an Executive supporting Leading Edge Designs (LED).  Our team has been providing lighting solutions and helping our clients overcome lights challenges for more than 9 years with a cost-effective, custom approach focused on understanding your needs and providing the most efficient solution.  We're passionate about helping to reduce energy costs, while shedding a little light on LED / solid state lighting...

Powered by Create your own unique website with customizable templates.
Photos from photoverulam, joelogon, JD Hancock, Veronique Debord