Saturday, January 02, 2010

Telegraph Collection Gas Energy Saver : Do Not Buy!

As an inventor, I was thinking about our gas stove, and how to increase the efficiency of heat transfer from flame to saucepan. I was doodling about with a design, and in researching it, found this item here. On the Telegraph marketing site.

Great. One less thing for me to do. So last May I bought a pair (£21 inc p+p) online.
They sit on the flame, go red hot, and as it says on the site,
"Most gas hobs burn gas inefficiently, resulting in expensive bills for your family. The Gas Energy Saver solves this problem by using a special catalytic alloy disc to convert all the unburnt gas to heat and energy instantly.

It fits all gas hobs, neatly sitting on your job, heating to over 1000oC, dramatically reducing your cooking time. The special stainless steel alloy is dishwasher safe. Measures 14x1cm (51/2x1/4in)".

Get that? "Dramatically reducing your cooking time".

Seven months later, I decided to quantify the amount of gas I was saving, with the following



Turn on gas, and leave it on at the same rate.
Take one saucepan, fill with one full egg-cup of water from the cold tap, place on flame, first with the Gas Energy Saver grid in place. Hit start button of stopwatch. Observe when boiling starts, which is taken as substantial bubbling occurring at the edge of the water. Record time. Remove grid, discard water (into a thermos flask, if you must know, so as to conserve the heated water), remove grid, refill saucepan with the same amount of water, and repeat.

I tried to keep the timings of the actions I took as regular as possible.

In all I took 16 readings, 8 with the Energy Saver Grid (ESG) in place, and 8 in the normal way, with the pan just sitting on the gas hob.


Number of seconds to end point with ESG in place:
106, 44, 137, 156*, 62, 145, 80*, 149
* = end point taken as evidence of boiling dry, with dry pan appearing before boiling was observed.

Average time to boil using the ESG : 110 seconds

Number of seconds to end point without ESG in place:

73, 28, 32, 60, 51, 51, 53, 43
Average time to boil without using the ESG : 49 seconds

There was a wide variation in the readings of the "Energy Saver" compared with the readings for the ordinary flame. This could have been due to variations on how the ESG sits on the hob, as it has a toothed structure, which if they are not bedded down on the hob, may hold the pot further from the flame, or not, depending how it is situated. It may be supposed that the device fails because it holds the pot further from the flame.

The Gas Energy Saver has been wasting a significant amount of energy. It is surprising that no trials were carried out on the invention before it was put on the market.

The appliance is not recommended by this blog.

Declaration: No money changed hands in connection with this experiment.

I will now have to fashion and trial my own design to increase the efficiency of heat transfer from flame to saucepan. Bother.

[update 25.1.10: Still no reply from the Telegraph Collection to my letter. 3 weeks now. It was just a polite letter of information. Perhaps they would reply if I mention the Trades Descriptions Act.]
[update 1.2.2010: Just got this email:
Your message

To:      Customer Services
Subject: Gas Energy Saver Trial
Sent:    Mon, 25 Jan 2010 19:38:10 -0000

was deleted without being read on Tue, 2 Feb 2010 16:16:00 -0000

Great. I'll send it again.
Update: a lab test contradicts my findings. 
The reason for this is that I was using my apparatus upside down. Which might appear to be stupid, but I was following the picture of the item. 
So now, when I get a round tuit, I will find the items, and repeat the experiment with them the right way up.


Anonymous said...

Is it possible that by having your without heating second, you are getting the benefit of lingering heat?

DocRichard said...

Not sure what you mean. There was residual heat, but it was the same in both cases.

I think a doubling of time to boil in the grid situation is fairly convincing, isn't it?

Unknown said...

Well thats really interesting as this Gas Energy Saver solves the problem by using a special catalytic alloy disc to convert all the unburnt gas to heat and energy instantly.I am impressed by this. really great and appreciable work i would say.

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DocRichard said...

Holy, you are a spammer. Anonymous, I repeated the triea through several cycles, so the residual heat in the pot was evened out. The residual heat in the disc should have biased the results towards shorter times for the disc.

Anonymous said...

The Telegraph never replied. Ebico, my ethical energy billing company, promoted the ESG, so I took it up with them, and after many emails, they have put me through to Nigel's eco-store,, who, I am told, are replicating the experiment.