Merlyn Farwell Group Home Studio Glass Furnaces
We custom manufacture and sell worldwide, You buy the best glass_blowing_equipment.
Energy Efficient Studio Glass Making Furnace, Kiln, GloryHole, Lehrs Combos, for Hobby or Career Glassblowing
Mr Robert Merlyn Farwell Camalot Castle 1 Parkfield Rd Stourbridge DY8 1HD
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Richard Golding

Richard Golding

Jake Mee

Jake Mee

Noreen Todd

Noreen Todd

Jonathan Ball

Johnathan Ball

Tim Harris

Tim Harris


We Circumvent Fossil Fuels Wasting Your Profit

Why do fossil fuels waste so much energy?

What you have to understand is that any fossil fuels must have oxygen to burn. You could, and some do, use pure bottled oxygen but that comes at a big additional cost. Most of us use an electric fan and the air around us, "its free", but air is COLD and only has 21% oxygen in it, the rest is mostly nitrogen (an inert gas). To be efficient the volume of oxygen and fuel must be absolutely correct to produce a Stoichiometric burn(see also). When you burn fossil fuel you automatically heat up everything including the nitrogen and then the waste gasses have to be removed so more fuel and COLD air can be put in to continue to heat the equipment. The HOT waste gasses (mainly nitrogen) carrying your costly heat are vented to atmosphere. That’s why WE put doors on a gloryhole or recuperate a furnace.
The above is simplistic, its actually somewhat more complicated by the fact that when you heat up cold air to say 1080c it expands by a factor of around 10, this demands that flue size is of critical importance especially in recuperation.



With regard to Furnaces, I NOW recommend Electric for a small studio.
Electrical energy is costly. It still uses fossil fuel but it is mass produced by the power companies and recuperation is not our problem. I have discovered how to use and control the cheaper Kanthal A-1 wire element with longevity, typically 2+ years and counting.  So running a furnace with electrical energy costs more BUT you use less because there are NO waste gasses and it’s easier, cleaner, silent and more controllable giving longer pot life.    When we use our super insulating “Castable”, together with modern high temperature materials in the construction, it becomes very cost effective and the furnace costs less to make and maintain.


A little tip "If you construct a gloryhole or a furnace out of a steel drum!! What you have actually made is a very effective costly RADIATOR."


How I got involved in Energy Efficient Studio Glass Making Equipment.

Having met Richard Golding in 2005 at his then Okra Glass Studio and being inspired with his approach to reducing running costs of the Gloryhole by utilizing modern materials, albeit in a most Heath Robinson way (I.E. 300 bulldog clips), this was something that Inventors need “A Problem”. My interest was heightened by the fact that when I left school age 15 (many years ago) my first job was Tecker In at Tudor Crystal Glass Works Stourbridge

Some years on embracing the laws of Thermodynamics, much prototyping and development and The Studio Glass Combo is here. A new type of integrated gloryhole, furnace and annealing oven. The glory hole/furnace is gas and the annealing oven uses the waste heat from the glory hole all day. Overnight the annealing oven is supplemented with an electric element, making the Combo the most energy efficient equipment available and AFFORDABLE.




Old & New Okra Glass Studio Jan 2009 by PIElectronics

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We made, installed and maintain Ruskin Glass College Hot Shop

4 GloryHoles made by us in 2007 still used daily at Ruskin Glass College


I am 66 year old Robert Merlyn Farwell, a prolific inventor for the last 30 years trading under the name PIElectronics (Pioneering Inventions & Electronics)
Rich in knowledge, enjoyment, health and happiness but not in the bank.
I am now persuaded to present the latest insights development product in a business way.


Glass is made by melting a recipe of minerals or cullet to high temperatures then manipulating molten mixture to desired shape. It must be controlled when cooling so there is no stress in the product at room temp. This can be done in a Lehr or annealing oven. Production glass processes use a Lehr which is a moving belt to transport the product through differing heat zones over time.  Small studios, strictly speaking, use an Annealing Oven which is a chamber where the temperature is electronically controlled over time.
If on this site I name something as a Lehr SORRY I mean  Annealing Oven. In 1961 when I started as Tecker-In at Tudor Crystal Glass Works Stourbridge the works operated 3 shifts 24/6. My job was to take the product from the crack-off to the Lehr (1 wine glass every min).



  In heat transfer, effectiveness is a measure of the performance of a heat exchanger when using the NTU method.