BOILERS AND EFFICIENCY

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BOILERS AND EFFICIENCY

• Gary Archer
• Vice President of Sales
• JW Stevens Co.

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BOILERS AND EFFICIENCY

• TYPES OF BOILERS STEAM
• Water tube, Fire tube, Cast Iron
• Fuels gas, oil, combination
• Typical Efficiencies 78-84

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HOW DO YOU INCREASE EFFICIENCY ON STEAM BOILERS?

• Burner/controls upgrades as discussed earlier
• ECONOMIZERS!!!!

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ECONOMIZERS
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ECONOMIZERS

• Take flue gases from the boiler to pre-heat water
  that can be used for potable use if you have a
  large need for domestic hot water. (i.e.
  Hospital, Food Processing )
• OR
• Use the hot water (260 degrees) to be used as
• boiler feed water. (Typical feed water
  temperatures are 160-225)
• Increases boiler efficiency by 3 or more and
  usually have less than an 18 months payback

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BOILERS AND EFFICIENCY

• TYPES OF BOILERS - HOTWATER
• Water tube, Fire tube, Cast Iron
• Fuels gas, oil, combination
• Typical Efficiencies 78-84
• MODULAR BOILERS!!!!

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MODULAR BOILERS
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MODULAR BOILERS

• Gas Only Natural or Propane
• Small Footprint
• Low mass/light weight design
• Non-Condensing and Condensing

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\What is a Non Condensing -vs- a
Condensing Boiler?
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Non Condensing Boilers

• These style boilers run in the 85-86 efficiency
  range regardless of return water temperatures.
• Vessel design must allow for continuous operation
  _at_ gt130 F return water temperature.
• Heat transfer (fireside) surfaces do not consist
  of materials resistant to acidic
  condensate and corrosive elements. They are
  typically made of copper
• Less expensive than condensing boilers
• Typical Applications are Standard building heat
  and/or indirect DHW.

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Condensing Boilers

• To achieve maximum efficiency a hydronic boiler
  must fully condense.
• This means the return water temperature back
  to the boiler must be below 130F. This allows
  for the flue gas temperature to drop below its
  dew point. This causes the water vapor in the
  flue gases to condense or change phase from a gas
  to liquid therefore giving off more energy
• Vessel design must be such that the flue gases
  are cooled down as low as possible.
• Heat transfer surfaces fireside must consist of
  materials resistant to acidic condensate and
  corrosive elements, typically stainless steel.
• Condensing boiler efficiencies can run as high as
  99.
• Typical Applications are radiant floor heating,
  snow melt, heat pump, hybrid heating systems

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Condensing
Non condensing
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Modular Boilers Hybrid System

• What Is a Hybrid System???

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Hydronic Boilers Hybrid System

• Hybrid Systems Utilize Both Non-Condensing And
  Fully Condensing Boilers.
• The Condensing Boilers Run In The Warmer Or
  Shoulder Months (i.e. October, November, March,
  April) while the Non Condensing Boilers Run In
  The Coldest Of Months.
• Building management systems can control the
  enabling or disabling of the two different type
  of boilers or most boiler manufacturers have
  their own stand alone controls that can achieve
  the same results.

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Condensing
Non condensing
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Hydronic Boilers Hybrid System

• In conclusion about Hybrid systems,
• Use the boilers that condense and get up to 99
  efficient when the outside air temperature is
  milder and supply water temperature to the
  fin-tube radiation in the occupied space can be
  lower
• Use the non-condensing boilers in the coldest
  months when you need high temperature water to
  keep the occupied spaces warm. This will achieve
  maximum seasonal efficiency.

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JW Stevens Co

• Stop by our booth to see a case study on a DVD
  loop to see an example of a hybrid system we did
  last year with Oswego CSD.
• They will earn well over 100,000.00 in National
  Grid Incentive Dollars