Boiler-boilers.How they work

Discussion in 'Water Heater Forum, Tanks' started by boilerdonganhhn, Apr 14, 2014.

  1. boilerdonganhhn

    boilerdonganhhn New Member

    Apr 14, 2014
    Ha noi
    Boiler or Boilers. How they work

    Objective: The objective of this presentation is to give you guys a fundamental understanding of how boilers can benefit our homes.
    Boilers provide warm, even heat throughout your home by circulating steam or heated water through a system of pipes and baseboard or radiator-type heat exchangers.

    How they work

    Basically, heat is created by burning gas or oil inside your furnace. Hot gases that are created pass through curved metal tubing called a heat exchanger and then out of your home through a metal or plastic vent pipe. At the same time, the air that circulates through your home passes over the outside of the heat exchanger and takes on the heat from the hot metal. The warm air is then circulated through your home
    They provide warm, even comfort without drafts because it's not a forced air system. Instead, warmth "radiates" throughout your home without causing much of the dryness associated with heat from a forced-air system, such as furnace or heat pump


    There are two types of boilers: gas and oil boilers and they can run on hot water or steam.
    The piping systems are different for each type.
    The hot water system boiler uses a pump to circulate the hot water while the steam boiler uses its own pressure to circulate the steam throughout the system. Both use a burner to heat the water to the temperature that is set on the thermostat. An aqua stat monitors the temperature of the water and turns the burner off when the temperature reaches the desired level. Steam boilers must heat the water to a higher temperature, and therefore have lower efficiencies than hot water boilers
    Combination boilers combine water heating and heat generation in one unit and can save considerable money on heating and water heating costs. The heating part of the "combi" boiler works in the same fashion as other boilers.


    The efficiency of new boilers is measured by the Annual Fuel Utilization Efficiency (AFUE). This is a measure of overall performance. The federal minimum-efficiency standards for boilers took effect in 1992, requiring that new boiler units have an AFUE of at least 80%.
    There are three key terms associated with efficiency of a boiler:
    Combustion efficiency - how efficiently the boiler burns the fuel.
    Steady-state efficiency - how efficiently the boiler uses the heat from combustion when operating under full load.
    Seasonal efficiency - how efficiently the boiler uses fuel over the entire heating season
    Although all three are important, it is the seasonal efficiency that is most important since it determines how much the building owner will pay for fuel over the course of the heating season
    High seasonal efficiency requires good steady-state efficiency as well as good combustion efficiency.
    There are a few things that can increase efficiency
    First, using two or three boilers can greatly increase efficiency.
    The longer a boiler operates, the higher the seasonal efficiency. Therefore, a boiler that is smaller than required will more closely match the heating load of the building for a larger part of the season because of fewer on-and-off cycles. When the first boiler can no longer keep up with the heat loss, a second boiler picks up the extra load, and then a third boiler, if necessary
    Each boiler will cycle one-half to one-third less than a single boiler, thus increasing seasonal efficiency significantly
    However, the key to maximizing efficiency with two or three commercial boilers is to be sure that each boiler is completely isolated from the others so that non-operating boilers will not be hot with system water.
    Some other ways to increase efficiency include eliminating leaks, softening or treating system water, using indoor/outdoor reset thermostats, and limiting control differentials.


    In conclusion, boilers can greatly benefit our homes by providing efficiently warm and comfortable heat evenly throughout our homes.
  2. nhmaster3015

    nhmaster3015 Master Plumber

    Jul 30, 2008
    The granite state
    Gee, thanks but its a pretty rare house that needs two boilers. Most have one in there that's twice as large as it needs to be in the 1st place.

    Not real sure how soft water is going to make much difference on a residential system either.

    Thanks for the can o spam though
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