The Modern Digital Flue Gas Analyser
As expected with new technology at the time of its release, there are usually technical problems. The digital flue gas analyser was not an exception to this rule but today’s equipment is far cheaper and is made to last longer than its predecessors ten years ago. However, when compared with the problems associated with using and maintaining manual wet combustion testing kits, the introduction of the digital flue gas analyser brought relief to heating professionals all over the world.
Manual versus Digital Flue Gas Analysers
Manual wet combustion testing kits for oil-heating appliances were bulky, susceptible to inaccurate readings, cumbersome, time consuming to operate and contained chemicals that were potentially dangerous to humans. The visual impact of the kit today would leave a customer, and indeed a heating professional, feeling a little apprehensive in view of its ‘archaic’ qualities.
However, in view of the modern professional digital gas flue analyser accompanied by its infra red thermal printer, a heating professional can connect his or her flue gas analyser to the heating appliance flue, monitor the data from the equipment and simply adjust burner components to acquire the required result within seconds of making that adjustment.
Fuel Economy and the Environment
With today’s higher heating fuel prices and depleting natural resources, the flue gas analyser is essential for maintaining fuel economy whilst reducing carbon and toxic emissions into the environment. Customers can now expect a shorter service time with combustion test results printed out immediately and attached to the heating appliance service record within minutes.
Through the use of the latest flue gas analysis equipment, the heating professional requires less service area to work in that helps maintain a cleaner environment within a customer’s property when compared to previous methods of heating appliance combustion testing.
Flue Gas Analyser Calibration and Servicing
Periodic servicing and calibration of digital flue gas analysers is essential. With the wide use of the flue gas analyser throughout the professional heating industry, the cost of servicing and calibrating a unit has seen a substantial fall in recent years. These costs will probably continue to fall, as more heating professionals realise the value and consequently the requirement of a digital flue gas analyser during installation or servicing of heating appliances.
Gas Service Engineer Competency
In 2010, it will be a requirement for all United Kingdom gas service engineers who install and service certain gas heating appliances to certify their knowledge in the correct use of a flue gas analyser. The CPA1 Combustion Performance Analysis of Domestic Appliances is a course and assessment intended for gas service engineers who employ combustion analysis as an essential element of the installation, commissioning, servicing and maintenance of a gas heating appliance, that is listed in BS7967 Part 3 2005 Guide, and to take appropriate action in respect of measurements obtained from a flue gas analyser.
In essence, the digital flue gas analyser is a boon for all heating professionals as it provides a customer with confidence and trust in their proficiency whilst in the knowledge that their heating appliance is operating effectively, safely and efficiently.
Flue Gases and the Serviceable Flue Gas Analyser
Flue gases are individual gases that are emitted to the atmosphere through specially manufactured metal, concrete, plastic or clay pipes or ducts, called a flue, which are specifically designed to allow the gases to safely pass from heating appliances such as a boilers, fireplaces, stoves, ovens and furnaces etc.
The specific content of flue gases depend on what particular type of fuel is used and how it is combusted will determine the constituents of the flue gases released. For example, a poor combustion process running at low temperatures with a poor air supply will invariably produce more pollutants than a combustion process with the correct combustion control factors of fuel delivery, ignition and air supplies etc. These are several reasons why a serviceable flue gas analyser is essential in realising the composition of flues gases within the combustion process of a heating appliance.
In essence, flue gases are the by-products of combustion and the combustion process determines their ultimate make up.
That said, flue gas or gases will primarily consist of uncombusted nitrogen taken from primary and/or secondary combustion air supplies, water vapour (H2O) created by the combustion of hydrogen in the fuel with oxygen (O2), also taken from primary and/or secondary air supplies, excess oxygen, again also taken from primary and/or secondary air supplies and carbon dioxide (CO2) which is the result of carbon from the fuel combined with oxygen.
Water Vapour
People often mistake the white plumes seen coming from flue terminals, as ‘smoke’ but is in fact water vapour condensing, as it comes into contact with cool air. These plumes are also more evident from heating appliances that use condensing heat exchangers, which recover more heat from the flue gases that would otherwise escape into the atmosphere. As of result of this action, the flue gases become a lot cooler and appear as water vapour in higher ambient temperatures when exiting the flue.
Flue gases will also contain smaller amounts of pollutants such as nitrogen oxides (NOx), sulphur oxides (SOx), carbon monoxide (CO) and particular matter derived from the substances contained in the fuel itself.
Nitrogen Oxides
Nitrogen oxides are highly toxic and are obtained from the nitrogen within the primary and/or secondary air supplies and from materials contained within the fuel. Heating appliances emitting significant amounts of nitrogen oxides will often cause irritation to the eyes.
Sulphur Oxides
The main source of sulphur oxides is the burning of fossil fuels. Sulphur oxides dissolves within water vapour in the air to form acids, and interacts with other gases and particles in the air to form particles known as sulphates and other products that can be harmful to humans and the environment.
Carbon Monoxide
Carbon monoxide is a tasteless, odourless, colourless and poisonous gas caused by incomplete burning of carbon-based fuels during a poor combustion process. Carbon monoxide accounts for most fatalities associated with flue gases from heating appliances.
The constituents of flue gases are within the control of the heating professional. As one of his or her primary responsibilities, the heating professional must be fully conversant with principles of the combustion process to overcome any potential problem associated with poor combustion performance of a heating appliance. Consequently, the use of a serviceable flue gas analyser is a fundamental measuring instrument for all who service, maintain and install fossil fuel heating appliances.