Bulbs.com
243 Stafford St.
Worcester, MA 01603
Tel. 1 (888) 455-2800
Fax 1.508.363.2900
www.bulbs.com
Bulbs Logo

21 Watt, 34 Inch T5 Cool White Fluorescent Bulb

SKU: U3000381 | Ordering Code: F21T5/841

In Stock
Price per Bulb
1 to 24 $5.99 Each
25 to 49 $5.79 Each
50 + $5.49 Each
Bulbs per Case
25
 x 
Add to Cart
Save to BulbTrack ?

My BulbTrack

Finding the lighting solutions you need might be simple at Bulbs.com, but buying them is even easier. Thanks to our exclusive BulbTrack feature, you can quickly and easily order the products you have purchased in the past or plan to order in the future by simply adding them to your My BulbTrack page. Products are added to your My BulbTrack page when you check out from your shopping cart or add them from the product description pages.

Once a product has been added to My BulbTrack, ordering it is as easy as entering the quantity or clicking on the product image. You can even add notes to each product to record where it is used in your business or home. Make buying your replacement lighting as simple as it should be. Create your BulbTrack today!

 

Product Details

Brand

Ushio

Energy Used

A rating, expressed in watts, to indicate the rate at which a lamp consumes energy. Also known as wattage value.
 
Energy Used
21 Watts

Bulb Shape

The description of the general appearance of a lamp/bulb consists of a letter(s) followed by a number. The letter indicates the shape of the bulb and the number relates to the diameter of the bulb in eighths of an inch. For example, a common household bulb is the A-19. The bulb is "A" shape and the diameter would be nineteen 8ths of an inch, or 2 3/8".
 
Bulb Shape
T-5

Base

The end (or ends) of the lamp that fits into the socket.
 
Base
Miniature Bipin

Diameter (in)

Light bulbs: a measurement of a bulb's width taken at the widest point of the bulb. Fixtures: the measurement across the widest point of a circular fixture.
 
Diameter (in)
.61

Length (in)

Also referred to as "Maximum Overall Length" (MOL). For light bulbs, it measures the length of a light bulb, from the top of the bulb to the bottom of the base or pins and is typically expressed in inches. For light fixtures and ballasts, it applies to the total horizontal length of the item.
 
Length (in)
34

Average Rated Life (hr)

A measurement of the average length of time, between first use and the point when 50% of the lamps tested have stopped functioning, , using an operating cycle of 3 hours on, 20 minutes off.
 
Average Rated Life (hr)
24,000

Brightness (Lumens)

A rating of the inital light output of a bulb, rated after 100 hrs of operation. Lumens are a measure of how much light falls on one square foot of area, one foot away from the light source.
 
Brightness (Lumens)
2,100

CRI

Color Rendering Index is an international system used to rate a lamp's ability to render object colors. The higher the CRI (based upon a 0-100 scale) the richer and more accurately colors generally appear. CRI differences among lamps are not usually visible to the eye unless the difference is more than 3-5 points.
 
CRI
85

Color Temperature (Kelvin)

An expression of the hue of the light emitted, measured in degrees Kelvin. Usually expressed by a four digit number followed by (k), such as 2700k. Higher temperatures indicate whiter, "cooler" colors, while lower temperatures indicate yellower, "warmer" colors. Some common Kelvin temperature benchmarks are 2700k (warm white), 3500k (neutral white), 4100k (cool white), 5000k (bright white), and 6500k (daylight).
 
Color Temperature (Kelvin)
4100K

GE

A General Electric brand-specific product number for an equivalent item and is provided for the purpose of cross-referencing.
 
GE
39978 - F21W/T5/841

Osram Sylvania

An Osram Sylvania brand-specific product number for an equivalent item and is provided for the purpose of cross-referencing.
 
Osram Sylvania
20835 - FP21/841

Bulb Technology

The technology implemented by the bulb, e.g. incandescent, halogen, LED
 
Bulb Technology
Fluorescent

Bulb Finish

The surface finish of a bulb, which may affect the quality of the light emitted.
 
Bulb Finish
Opaque

Bulb Color

The color of the light produced by a bulb
 
Bulb Color
Cool White
Description
 
Reviews
 
Q & A

Ushio energy saving T5 fluorescent lamp.  21 Watts and 34 inches to fit shorter commercial fixture lengths. 

  • Cool white color is very popular for most businesses

  • T5 technology last longer than traditional T12, with greater lumen maintenance over time.

REVIEW SNAPSHOT®

by PowerReviews
Ushio21 Watt, 34 Inch T5 Cool White Fluorescent Bulb
 
5.0

(based on 2 reviews)

Reviewed by 2 customers

Sort by

Displaying reviews 1-2

Back to top

 
5.0

it is a light bulb, works well...

By Bruce

From Tyrone, Georgia

About Me Quality Oriented

Verified Buyer

Pros

  • Bright
  • Fast shipping
  • Long Life
  • Reduces Energy Costs
  • Runs Cool

Cons

    Best Uses

      Comments about Ushio 21 Watt, 34 Inch T5 Cool White Fluorescent Bulb:

      it is a light bulb, works well... fast shipping!

      • Primary use:
      • Personal
       
      5.0

      great bulb value, very bright

      By Dannie

      From Simi Valley, CA

      About Me Quality Oriented, Value Oriented

      See all my reviews

      Verified Reviewer

      Pros

      • Bright
      • Long Life
      • Reduces Energy Costs

      Cons

        Best Uses

        • Kitchen

        Comments about Ushio 21 Watt, 34 Inch T5 Cool White Fluorescent Bulb:

        easy to install

        Displaying reviews 1-2

        Back to top

        Do you have questions about this product?

        get answers from real customers and in-house experts with AnswerBox.

        1 Question | 1 Answer
        Displaying question 1
        • Q:

          Is this bulb compatible to F21T5/DL?
          Asked on 2/18/2011 by Anonymous

          1 answer

          • CUSTOMER CARE

            A:

            This bulb is similar to an F21T5/DL with the exception of the color temperature. The "DL" most likely refers to a daylight bulb. The color temperature can be anywhere from 5000K to 6500K depending on the manufacturer. This particular bulb on our website is a cool white bulb and will not appear as bright as the DL bulb. We do offer a bulb that is a 21 watt, T5 with 6500K color on our website. This bulb can be found on the following link. http://www.bulbs.com/T--5_Linear/10W_--_49W/Daylight_White/results.aspx.

            Answered on 2/21/2011 by Product Support from Bulbs.com
        Displaying question 1

        Do you have a question about this product? 

         
        BulbFinderNot sure how to find your bulb? Click here for our step-by-step tool.