Gas Condensing Boiler

Power Output  12 – 900 kW ( Will modulate down to 12kW or 22kW depending on model size)gas condensing boiler

Gas Condensing Boiler – Modulating, Low N0x, multi-burners, condensing boiler, for indoor/outdoor installation, IP X5D, containing pre-assembled thermal modules without hydraulic interception in between. For flexible temperature operation, suitable for natural gas or LPG fuels ,4 star efficiency class according to the European Directive 92/42

The Modular Gas Condensing Boiler Concept

Gas Condensing Boiler -Each heat generating module within our Modulex boilers is self-contained, with its own down-firing pre-mix gas burner, fan, ignition and safety controls. As the system load decreases, a built-in Boiler Cascade Manager modulates the boiler down to the combined minimum. As loads continue to reduce, individual modules are switched off as necessary down to a minimum output of a single module – 12 kW for 100- 350 kW models and 22kW for 440-900 kW models.This ensures optimum load matching and minimizes wasteful boiler cycling, whilst maximizing energy efficiency in the process.The combination of a high modulation ratio up to 1:40 and a high output plus very low water content ensures rapid warm-up and turn-down times for Modulex boilers. They are subsequently also able to respond quickly to changing demands throughout the heating period.Thanks to their modular design, these gas condensing boilers will continue to operate even in the unlikely event that a single module malfunctions.

 Technical Specification for the Modulex Range

Our Gas Condensing Boiler Range Features –

  • 11 models with outputs ranging from 100-900 kW
  • You can cascaded up to 8 boilers for higher output requirements (potentially 7,200 kW of heating power ! )
  • High energy efficiency – up to 109% at the minimum modulated capacity
  • High modulation range up to 1:40
  • Modulating pump – directly managed by the boiler to assure the maximum condensation at all times
  • Available for Natural G as or LPG ( Propane )
  • Extremely low emissions  : <31 ppm Low NOx (according to EN 15420)
  • Compact dimensions – Ideal for tight boiler houses
  • Flexibility of installation -reversible hydraulic and gas connections (up to the model -350 kW) and the flue pipe connection is flexible and can be re-positioned : possible on all 3 sides (for all the models), which gives huge flexibility, when having to conform to site conditions
  • Ultra-low operating noise levels (<49 dBA)
  • Flue outlet can be positioned in three different locations (Right Hand / Left Hand or Rear of the boiler) – Giving you maximum flexibility to suit the site conditions
  • Can be mounted externally as it’s a IPX5D rated Gas Condensing Boiler, saving valuable space and is fully weatherproof ( Please see pictures below )

gas condensing boiler

Gas Condensing Boiler with a Compact Primary Circuit and Mixing Header – For External Use – With Weatherproof Cover

Gas Condensing Boiler

Gas Condensing Boiler with a Compact Primary Circuit and Plate Heat Exchanger – For External Use – With Weatherproof Cover

 The Flexible Gas Condensing Boiler features –
• 4 star efficiency class according to the European Directive 92/42
• Floor standing condensing gas boiler
• Each aluminium/silicon/magnesium module has its own combustion chamber with a total radiation burner, modulating fan, gas valve, flame and ignition BMM control device, NTC sensor for local temperature control and safety thermostat
• Adjacent thermal elements for an optimum reduction of heat losses
• Hydraulic connection between adjacent elements without interceptions through hydraulically balanced manifolds
• Complete non-allergic synthetic wool insulation, 50 mm thick
• Total pre-mix modulating burners, with flame surface in metallic radiating mesh.
The air – gas premixing occurs within the fan, with built-in check valve
• Pre-mixing occurs in the pre-combustion chamber
• Air suction system from the boiler room or directly from outside of the boiler room through ducts (optional)
• E8 heating controller placed on the special disappearing panel board
• System loads management of up to 2 mixed circuits (up to 15 with optional expansion modules) and a DHW storage tank load
• Standard delivered: Outer temp. sensor, flow temperature sensor and DHW storage tank sensor
• Made with water proof casing; IP X5D
• Possibility of cascade installation of 2 or more boilers (up to 8), by using an additional E8 controller as MASTER.
Gas Condensing Boiler Optional Accessories : room temperature.sensor, solar temperature sensor, zones expansion kit, control for an additional zone BM8

Gas Condensing Boiler method of operation:
• Maintains the major number of modules firing at the lowest possible rate (up to 12 kW for mod. 100-350 and up to 22 kW for models 440-900) in order to obtain the maximum efficiency
• Automatic working hours sharing among the different modules, so as to ensure the same operation time for all the modules
• D.H.W. production through a priority sensor, that controls a dedicated loading pump or a 3-way diverting valve via the E8
• Possibility of controlling the output of each single module
• Automatic management of the supplied output, of the temperature setpoint and the 0 – 10 V signal to the modulating pump, depending on the installation parameters (BCM)
• Supervision of boiler operation and temperatures status
• Alarms management
• Parameters setting
• Command relay for activation of a constant flow rate pump

ADDITIONAL FUNCTIONS of the BCM (supplied with this gas condensing boiler range)
• 0÷10 V outlet for modulating pump control
• Emergency operation: anti-blackout through BCM: Constant set-point temperature operation at 70°C (adjustable) and maximum output of 50 %
• Alarm signaling relay

Gas Condensing Boiler Optional accessories:
– Acidic condensate neutralizers
– Primary circuits: (also in pre-assembled and tested version: plug & play), hydraulic system interface with additional safety devices kit and modulating pump (possible combination with mixing header or plate heat exchanger)
– Expansion accessories and remote controller E8

Gas fired condensing boilers do not only maximise the supplied energy, when compared to conventional gas boilers, they also utilize the thermal energy contained in the flue gas, which is otherwise lost through the chimney

Condensing gas boilers achieve a significantly higher efficiency which results in a reduction in heating costs and emissions. The Flexiheat range of gas-fired condensing boilers are also suitable for domestic hot water via a plate heat exchanger or calorifier, as well as heating

How a gas condensing boiler works

In a gas fired condensing boiler, hot water is generated through the heat of combustion, just like with non-condensing boilers. The resulting flue gases are commonly passed into the chimney. As a result of this, the energy which is contained in the flue gas is lost. However, condensing technology exploits and uses these gases. These gases consist, to a large extent, of hot water vapour. The flue gas heat is extracted and then feeds the energy recovered into the heating circuit.

In order to gain energy, water vapour must condense. It does this at a temperature of below 56°C for natural gas fired condensing boilers. The condensing boiler cools the steam through a specially designed heat exchanger. The energy gained is then used to preheat the cold heating water. The hot water then passes through into the primary heat exchanger where it is then heated further to achieve the desired temperature. During this process, a small amount of waste water occurs which must be disposed of. The acidity of the waste water is so low that it can be conducted into a normal drainage system without further neutralisation.

The difference between upper and lower heating value, in relation to high efficiency boilers

When we talk about the high efficiency of 98% of condensing boilers, the value actually refers to the “upper heating value”. This must not be confused with the “lower heating value” with which the industry usually makes its calculations. The lower heating value is the amount of heat that can be utilized in the combustion of an energy source, without causing condensation. The lower heating value therefore only contains a portion of the total fuel energy.

In comparison, the ‘Upper Heating Value’ also includes the volume of heat that is contained in the flue gas & water vapour, which can be utilized by condensation. When calculating for the input energy the upper heating value takes this extra heat into account. The efficiency of a heater, also known as ‘Standard Efficiency’, can reach a maximum of 100% in an ideal scenario when calculated on the basis of the upper heating value

Condensing boilers – Chimney / Flueing System

With the installation of condensing gas boiler, another benefit is that the flue system can often be a plastic pipe system, which means that they are smaller in diameter than conventional gas boilers, cheaper , easier to install , lighter in weight and easier to fit. All of condensig gas boilers within this range  have a maximum pressure of 100 Pa available at the chimmney outlet . Pa or Pascal is an expression of air pressure , and has been since 1971 , and everything , that you attach to the exhaust gas outlet / flue pipe outlet causes a frictional resistance, and this depletes the amout of PA available after going through the flue pipe or a flue bend in the exhaust system.

We have some approxiamte values for calculating how far you can flue these gas condensing boilers –

For every 1 metre of Flue pipe ( it doesn’t matter if it’s horizontal or vertical ) you use 2 Pa of pressure

A  90 Degree bend , you use 20 Pa of pressure , for a 45 Degree Bend you lose 10 Pa of pressure .

Please bear in mind that you want some pressure at the terminal of the flue system – say 10 Pa

Thus a modulex gas condensing boiler , which produces 100 Pa of exhaust gas pressure , will do  –

1 x 90 Degree Bend – 20 Pa

1 x Flue outlet pressure – 10 Pa

This gives a total of 30 PA , meaningh that you have 70 Pa to play with , which would mean you could go 35 metres Horizontally or Vertically with the Flue pipe / Chimney sytem.

The benefits of a gas condensing boiler –

  • Lower heating water temperatures
  • Better insulation and less loss due to heat radiation
  • Fully automatic temperature regulation depending on outside temperature
  • Significantly lower pollutant emissions than conventional gas boilers
  • Efficiency with gas: up to 110%

Commercial Gas Boilers

Since the ErP ( Energy Related Products Directive ) Heating Classifications that came into force on the 26th September 2015 , all boilers up to 400 kW have to meet new efficiency levels. which basically means all commercial gas boilers , up to 400 kW , are now condensing. This not only benefits the end-user , it means reduced emissions and significant savings in energy. We have reports from some of our customers that they have seen gas consumption savings of up to 35% by upgrading to a gas condensing boiler.
So if you require one of the best condensing gas boilers on the UK market, please don’t hesitate to contact us

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