Kiln Support
Paragon HomeKiln ProductsWhere To Buy KilnsKiln SupportAbout ParagonKiln Resellers and Dealers
Search Menu

Kiln Pointers

Estimating Heat Loss Through Bead Doors

The Paragon BlueBird Jr has two bead doors.


Estimating Heat Loss Through Bead Doors

Reader Response: Checking glass visually; the nerve-wracking side to creativity

Recent Q&As: Program Review on the Sentry Xpress controller

A Kiln Story: The Hot Circuit Breaker

Memorable Quote

News: Family Employee Returns to Paragon



By John S. Hohenshelt, President of Paragon

Many people are concerned about the doors of bead annealing kilns being partly open when the rods are placed inside the kiln. The concern is the amount of heat that is lost around the door. There will be some loss of heat, but it is very minor. Here is the analysis.

Electricity costs about $0.13 per kilowatt hour. This means you have to run a 1000-watt device for one hour straight to use $0.13 of electricity. Most annealing ovens power the heating elements for only about 50% of the time they are "ON". This is easily observable by the clicking ON and OFF of the relay. The kiln pulls the kilowatts only when the relays/elements are ON. Most bead annealing ovens are 120 volt devices that are rated around 1.5 kilowatts. So if the oven pulls power for one straight hour, the cost is about $0.20. (1 hr x $0.13 x 1.5Kw).

If the elements are only on 50% of the time, the cost is $0.10 of electricity for one hour of firing. So if the bead artist has the kiln running for four hours and then turns it off to naturally cool the beads, the cost is only about $0.40 for the entire firing. Once this is understood, the amount of heat lost through the open bead doors cannot amount to much. Even if the open doors require 20% more energy to maintain the heat, the duty cycle goes to 60% and the total cost of the four hour firing is increased by $0.08.

Hopefully this explains why having the bead doors slightly open for annealing should offer little concern for the bead artist.



“Firing Glass Visually,” the last Kiln Pointer, was about checking the hot glass through a kiln peephole or window. Julia Larson, a glass artist in St. Petersburg, Florida wrote, “I have a pendant I call birds' nests that I fire in a small kiln that has a viewing window. I fire slowly to 1100 degrees F. Then I turn the kiln up to full and watch carefully from 1350 degrees on until the fuse reaches the desired state. It amazes me how the temperature can vary at the ‘right’ stage depending on the glass I use and the number of items I have in the firing.”

Debbie McKown of Acton, Massachusetts wrote, “Thank you for sharing the inspirational roller coaster people* quote by David Kittrell. I'm going to hang a copy in my studio. Although my confidence is building, firing enamels makes me extremely nervous because so many things can go wrong. Despite my best efforts, complications occur, such as a speck fused onto an otherwise perfect tile! Very disappointing!

“Reading David's quote will be a reminder that it is my conscious choice to work in enamels because they are so beautiful. What a wonderful feeling to see how people enjoy looking at them.”

*“It is us, the roller coaster people, who embrace the rising to the top, who savor the view from there, and then take the sinking to the bottom as not a tragic moment, but as another chance to rise all the way to the top again.” --David Kittrell



Q. I have never figured out how to use the review mode on my Paragon Home Artist kiln. It has the feature indicated on the instrument panel, but I can't for the life of me figure out how to activate it.

A. The Sentry Xpress Program Review works only while the kiln is firing. Press the Down Arrow. The program that is firing will appear one step at a time.



Steve Worcester in Plano, Texas wrote, “I have a GL-24 that kept blowing the circuit breaker after a few years. The kiln was on a 50 amp breaker with 6 gauge wire that runs only about 6 feet, so the circuit wire wasn't the issue.

“After about an hour of firing, the breaker popped. I took off the breaker box cover plate. Using a cheap infrared thermometer gun from Harbor Freight, I found that the breaker was at 180 degrees F. I replaced the breaker, which works fine now. The breaker must have worn out.”



The darkness is temporary. Latin: "Post nubila phoebus" ("After the clouds, the sun...)"



Hi, this is Kelly Bartholomew at Paragon. I wanted to take a minute to introduce myself. I rejoined our family business in October, 2010, which brought my career full circle. Along with my siblings John (the president of Paragon), Charlie, and Amy, my first job was at Paragon. We spent summers during our high school and college years working at Paragon for our dad, John R. Hohenshelt. I helped to hang the ceiling insulation in the factory during a hot Texas summer, built control boards, and assisted in the print shop under Arnold’s supervision.

After working in the accounting field and being a stay-at-home mom to my three boys, I am back! My current job at Paragon includes accounting and HR activities and special projects. I am looking forward to getting to know our wonderful customers and gaining knowledge of their intriguing art forms. Please let me know if I can assist you in any way!


Last week a storm blew through Mesquite. The rain poured so hard that it formed a mist as it bounced off the streets. Rapid flashes of lightning revealed a distinct wall of blackness that looked like the edge of a bulging tornado--but it wasn’t. After the storm passed, I collected golf ball size hail stones from my driveway.

I hope spring has been beautiful where you are and that you had a safe Memorial Day weekend.

Thank you,

With best wishes,

Arnold Howard Paragon Industries, L.P. – Better Designed Kilns 2011 South Town East Blvd., Mesquite, Texas 75149-1122 Voice: 972-288-7557 & 800-876-4328 / Fax: 972-222-0646 / / /

PRIVACY NOTICE: Under no circumstance do we share or sell your email address.

Copyright 2011, by Paragon Industries, L.P.

Paragon Kilns on FacebookParagon Kilns on Twitter Paragon Kilns on YouTube Paragon RSS Feed

Kilns Sold

Get The Adobe Reader


  • Home
  • Privacy Statement
  • Legal Notice
  • Paragon's Green Statement
  • Where To Buy Kilns
  • Resellers
  • About Us
  • Contact Paragon
  • News & Events
  • Support

  • Kiln Technicians
  • Kiln Support
  • Products

  • Bead Kiln
  • Glass Blower's Crucible Furnace
  • Ceramic Kilns
  • China Painting Kilns
  • Enameling Kilns
  • Industrial Furnaces
  • Glass Kilns
  • Lamp Working Kilns
  • Pottery/Ceramic and Glass
  • Pottery Kilns
  • Silver Clay Kilns
  • Wax Burnout Furnaces
  • Heat Treating Furnaces
  • Knife Making Furnaces
  • Custom Furnaces
  • Discontinued Models
  • “Custom and standard Kilns and Industrial Furnaces for ceramics, pottery, heat treating, enameling,
    dentistry, laboratory, and glass fusing.
    Better Designed Kilns from Paragon Industries!"