condensing boiler flue gas temperature

Condensing vs. Non-Condensing Boilers: What's the Difference

Traditional Non-Condensing Boilers. This problem usually occurs when the flue gases reach the dew point when cooling, which can occur in colder climates and during cooler seasons. This issue can be reduced by having a minimal return water temperature of 150 degrees.

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Condensing boiler - Wikipedia

Condensing boiler manufacturers claim that up to 98% thermal efficiency can be achieved, compared to 70%-80% with conventional designs (based on the higher heating value of fuels). Typical models offer efficiencies around 90%, which brings most brands of condensing gas boiler in to the highest available categories for energy efficiency.

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Condensing Boiler | behrmann-company

Boilers can only condense when the flue gases within the boiler are at their dew point of 134.6°F or 57°C. So to ensure continuous condensing operation the heat exchange surfaces and therefore the return water must be at this temperature. There are two ways to achieve this. Design the heating system so that its return temperature is low (underfloor systems for example).

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Condensing boiler - Wikipedia

Condensing boiler manufacturers claim that up to 98% thermal efficiency can be achieved, compared to 70%-80% with conventional designs (based on the higher heating value of fuels). Typical models offer efficiencies around 90%, which brings most brands of condensing gas boiler in to the highest available categories for energy efficiency.

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Considerations When Selecting a Condensing Economizer

An indirect contact condensing economizer (see Figure 1) removes heat from hot flue gases by passing them through one or more shell-and-tube or tubular heat exchangers. This economizer can heat fluids to a temperature of 200°F while achieving exit gas temperatures as low as 75°F.

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Managing Condensate for Condensing Boilers - Automatic Heating

The condensing process is achieved by passing the piped hot flue gases through the cooler return water flowing back into the boiler. Flue gas starts to condense when it drops below its dew point of 55°C. This is why condensing boilers are designed to accommodate a return water temperature of 54°C or less.

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Best Condensing Boiler | Which Boiler has the Highest Energy

To minimize any heat loss from the flue gases, its important for the boilers heat exchanger to allow water vapor condensation. A condensing boiler works at its best when the heat exchanger surface is equal or below whats called the dew point temperature. Normally, the dew point temperature for natural gas is around 55 degrees Celsius.

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Getting the Most Out of Your Commercial Condensing Boiler

Apr 11, 2012 · The vapor in the flue gas only starts to condense at about 130° F return water temperature. You get very little increase in efficiency beyond non-condensing operation at this temperature. Slightly above a 70° F return water temperature is when you hit the 98%-99% efficiency numbers you often see advertised.

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Back to Basics: Venting for Gas-Fired Boilers | 2003-06-04

Jun 04, 2003 · As the efficiency of a boiler goes up, the temperature of the flue gases go down, and the gases are more likely to condense in the flue. When combustion efficiency exceeds approximately 83%, there is a good possibility that the flue products will condense.

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What is a Condensing Gas Boiler? | U.S. Boiler Company

Traditional vs. Condensing Gas Boilers. Traditional gas boilers burn natural gas or propane to heat the water in a home heating system. These boilers are vented to the outside via a chimney flue or vent pipe. Traditional boilers typically operate at higher temperatures, which means that a portion of heat is vented to the outside during the

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Is a high efficiency, condensing gas boiler the best choice

Aug 13, 2018 · At this point, flue gas temperatures drop and as the flue gas cools, condensate forms in the heat exchanger. Condensing boilers cool the exhaust gas so much that they can be vented with CPVC or Polypropylene (plastic) pipe, instead of the steel venting required by conventional boilers.

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How gas condensing technology works | Viessmann

The latter consist mainly of hot steam, the components of which can be acidic. To protect the boiler itself and the flue gas system from this acidic steam, older boilers direct the flue gases outside. Depending on the heating technology, the exhaust gas temperature can be up to 200 degrees Celsius.

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Boiler Efficiency | Kane International Limited

Boiler Efficiency. The objective of a boiler is to burn the hydrogen contained in the fuel with oxygen from the atmosphere to produce heat. Combustion efficiency analysers exploit the fact that by knowing the fuel (and its chemical composition) and measuring the flue gas temperature and either the oxygen or carbon dioxide level the efficiency of the boiler can be calculated.

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Consulting - Specifying Engineer | Boiler systems: Economics

Jun 19, 2012 · As shown in Figure 1, with a system return water temperature of 130 F, condensing boilers are approximately 87% efficient, but this efficiency can go as high as 98%, with a return water temperature of 60 F.

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Is your condensing boiler actually condensing? | YouGen Blog

The dew point is at 55 degrees, and for the boiler to condense the temperature of the water that returns to the boiler must be 55 degrees or below. Many are set up with a flow and return temperature of 70 degrees.

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