Product category:
Heating Systems, Controls and Management
News Release from: Johnson and Starley | Subject: Everything in modulation
Edited by the Buildingtalk Editorial
Team on 31 January 2006
Everything in modulation
Stan Bell of Johnson and Starley talks about the importance of a boiler's modulation characteristics and its ability to respond to warmer winters.
Stan Bell of Johnson and Starley talks about the importance of a boiler's modulation characteristics and its ability to respond to warmer winters Back in 1973 climatologists were warning about the possibility of there being another ice age, not global warming At this time, the first scientific papers looking at the probable link between CFC propellants and the newly discovered hole in the ozone layer were being dismissed as irrelevant
This article was originally published on Buildingtalk on 6 Aug 2008 at 8.00am (UK)
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In terms of our fossil fuel consumption 'coal was still king', while reserves of North Sea oil and gas appeared inexhaustible.
It might seem strange then that one of the UK's few specialist manufacturers of heating appliances was, at the time, launching a warm air heater with the first modulating control system.
The simple truth is that Johnson and Starley has, whatever the market conditions, always invested strongly in research and development in an effort to ensure its customers are offered the best in terms of performance and reliability.
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Johnson and Starley specialises in the design and production of a comprehensive selection of ventilation and heat recovery equipment where the installation of ductwork is not practical.
So it is then that the company's first wet boiler, launched last year, presents a package of sophisticated, well engineered features that enable it to deliver high efficiency for the maximum proportion of the time it is operating.
Not only do the boilers in Johnson and Starley's Reno range incorporate stainless steel heat exchangers, Honeywell controls and circulators produced by world leader Grundfos Pumps, they are all able to modulate down to 7 kW.
Commenting on the significance of the original Modairflow system, Stan Bell comments: "Not only do we have more than 30 years experience of modulation since producing the first modulating controls in 1973, we have put this knowledge to work in respect of the most pressing environmental and statutory requirements".
""It is the case that the principle of modulation on a wet system and a hot air system is exactly the same - so even though the Reno is our first actual boiler, we have been able to use our long experience to optimise its performance.
"The fact is that with Reno boilers, when in central heating mode, their burners will modulate down from 25 to 7 kW.
Most boilers on the market will only modulate down to 10 or 9 kW at best; Reno is unique in respect of this capability".
"It is therefore a real technical achievement and a measure of our expertise to get a boiler to modulate over such a large range and still maintain its efficiency." It has often been said that condensing boilers are fine when they are in the condensing mode, but when they're not they operate just like a standard efficiency boiler.
It is an interesting point then that when the Reno drops out of the condensing mode, it still operates at an efficiency of around 84 per cent which is more efficient than standard efficiency appliances.
However, the Reno will keep performing in the condensing mode for more of the time due to the modulation range.
If one considers a typical traditional three bedroom semi-detached property, the heat loss will be in the order of 12 kW when calculated with an outside temperature of -1 degree c.
The problem is that in the UK we only experience these temperatures for four to five weeks in the year; more normally a boiler is working to a much smaller temperature difference between inside and outside.
At 10 degrees c outside temperature, for instance, the calculation with our average semi comes out at a heat loss fractionally below 7 kW - a boiler modulating to 9 kW will only condense when the outside temperature is less than 5degrees c so the efficiency is not there.
The example shows that Reno is efficient for much more of its operating time than a comparable unit modulating 2 or 3 kW above Reno's bottom range.
As Stan Bell explains, "It follows that running costs are lower, component lifespan is increased and noise levels are reduced - all important factors in the choice of boilers".
He continues: "We employ thermistors to constantly measure the temperature of the flow and return and therefore the temperature differential".
"This is then monitored by the control panel which tells the burner how high or how low to fire".
The Reno's burner will adjust the output according to demand and therefore reduce in output while maintaining its efficiency.
This makes it more economic to run.
It cycles less than a boiler which will not modulate as low, and the whole set up runs more quietly.
There is a bedazzling selection of SEDBUK Band A boiler packages available on the market now, offering every type of attraction from radio frequency communication with the room stats to luxury holidays for installers.
Johnson and Starley might well be inclined to observe, "everything in modulation".
Johnson and Starley were established in 1922 and for over 80 years have provided innovation to the UK heating industry.
As a manufacturer of 'Home Comfort Solutions' the company offers an extensive range of warm air heaters and ventilation products in addition to high efficiency boilers.
They offer the complete heating and ventilating range to heating installers and specifiers.
Johnson and Starley has built up a reputation as a manufacturer of high quality, reliable, long lasting, fuel efficient products which offer cost effective solutions. Request a free brochure from Johnson and Starley ...
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