Selecting Equipment for Ferris State University

1
ARI Conference 2007

• Selecting Equipment for Ferris State University
• HVAC 462 Course Assignment
• Joe Pacella
• The purpose for class HVAC 462 is to learn how to
  select primary pieces of equipment.

2
HVAC 462 Preliminary Information

• The courses that the students have had prior to
  this course are the following
• 1. Prior Associate Degree in HVAC from FSU or
  Transfer Student
• 2. HVAC-331
• HVAC Secondary Equipment Selection Design
• Hydronic Pumping Systems
• Pump and pipe sizing
• Air Handling Systems
• Ductwork and fan sizing
• 3. HVAC-342
• Commercial Load Calculations and Energy Code
• ASHRAE Fundamentals
• ASHRAE Standard 62
• ASHRAE Standard 90
• ASHRAE Standard 55

3
HVAC 462 Preliminary Information

• 4. HVAC-312
• HVAC Control Theory and Applications
• Electronic control terms and applications
• Control valve sizing and selection
• Sequence of Operations
• AutoCAD generated drawings
• 5. HVAC-393
• Required internship between the Junior Senior
  year of classes.

4
HVAC-462 Primary HVAC Equipment Selection

• Students are required to create a schedule for
  each piece of equipment
• Heat Exchangers
• Water/water or steam/water heat exchangers
• Cooling towers
• Chillers
• Air cooled water cooled
• Air Handling Units
• Packaged, rooftops, blower coils and
• modular constructed air handling units
• Boilers
• Hot Water and Steam
• Co-generation Tri-generation Systems
• Thermal Storage
• Engineering Economics
• Time Value of Money
• Based upon ASHRAE information

5
Cooling Towers

• Step thorough the process our students experience
  with heat exchangers specifically Cooling towers
• Natural Draft Forced Draft

6
Cooling Tower Selection

• Cooling Tower
• A specialized heat exchanger in which two fluids
  are brought together in direct contact with each
  other to affect the transfer of heat. The fluids
  are air and water. It is accomplished by
  spraying water in one direction (much like rain)
  and inducing the flow of air thru the water
  spray.
•  

7
Cooling Tower Selection

• Factors that effect tower sizing
• 1. Approach temperature The difference between
  the cold water temperature leaving the tower
  and the wet bulb ambiant temperature.
  Approach is used to fix the operating
  temperature of the tower and is the key
  variable in cooling tower sizing.
•  
• 2. Entering Wet Bulb The lowest temperature
  that water can theoretically reach by
  evaporation. Measured with a psychrometer.
• 3. Range The difference in temperature
  between the hot water entering and the cold
  water leaving the cooling tower.
•  
• 4. Total Heat Rejection GPM x R (range) x 500
  Btu/hour
• 500 (8.33 /gallon)(60 minutes/hour)

8
Cooling Tower Schedule

• The purpose of creating a schedule is to
• 1. Clearly articulate the design so that it the
  system is possibly designed correctly
• 2. Allow the customer to obtain competitive bids
  on various system installation contractors
• 3. Allows the customer to obtain competitive
  bids on equipment. There is always a basis of
  design.
• Manufacturer Model Number
• Number of Cells
• Fan Data (type, of blades, rpm, quantity
  airflow)
• Motor Data (nominal horsepower, rpm
  efficiency)
• Water flow rate (gpm)
• Water Temperatures (inlet outlet)
• Design Wet Bulb Temperature
• Approach (F)
• Range (F)
• Estimated evaporation rate (gpm)

9
SPX Towers (Why SPX?)

• The student is requried to gain access to the SPX
  (Marley) web site at
• http//spxcooling.com/en/ ( or use a search
  engine for Cooling Towers)
• Pick the tower sizing and selection on the screen
• The student sets up their own access or they can
  login as a Guest
• Looking for cooling towers are factory-modular,
  induced-draft, cross-flow, vertical discharge
  cooling towers
• This assignment requires an NC class tower
• The student has to find the correct tower by
  reviewing different types unts
• The student sets up their own access or they can
  login as a Guest
• Fill in the appropriate Job Information tab
  (Default Tab)
• Important so that the proper information is
  selected and displayed

10
SPX Towers Design Conditions (1st SELECTION)

• The student is requried to gain access to the SPX
  (Marley) web site at http//spxcooling.com/en/
• Click on the Design Conditions tab and fill in
  the following conditions
• Enter 1,000 GPM
• Enter Hot Water Temperature of 95 deg F.
• Enter Cold Waater Temperaure of 85
• Wet Bulb Temperature of 78 deg F.
• Numebr of Cells defaulted to calculate
• Solve for Capacity
• 2 tolerance
• Fluid Cooler Requirements leave to none
• Free cooling/low ambiant options
• Maximum coil pressure drop default 25 psi

11
SPX Towers Evaluation Parameters

• The student is requried to gain access to the SPX
  (Marley) web site at http//spxcooling.com/en/
• The evaluation parameters have been left alone
  for our exercise.
• Allows such configuration changes as
• Cooling tower fan type (single speed, two-speed
  or variable speed)
• Efficiency of the electrical motor
• Wet bulb profile
• Once the parameters are input depress the select
  key
• A print out of all of the possible products are
  listed
• Can be sorted by various methods (capacity, fan
  BHP, cost ratio etc)
• We have the students base their selections on
  capacity only
• Note their may be a available cooling towers that
  do not meet capacity
• The tolerance will dictate as to the availability
  of the units

12
SPX Towers Design Conditions (2nd Selection)

• The student is requried to gain access to the SPX
  (Marley) web site at http//spxcooling.com/en/
• Click on the Design Conditions tab and fill in
  the following conditions
• Enter 500 GPM
• Enter Hot Water Temperature of 105 deg F.
• Enter Cold Waater Temperaure of 85 deg F.
• Wet Bulb Temperature of 78 deg F.
• Numebr of Cells defaulted to calculate
• Solve for Capacity
• 2 tolerance
• Fluid Cooler Requirements leave to none
• Free cooling/low ambiant options
• Maximum coil pressure drop default 25 psi
• Once the parameters are input depress the select
  key

13
ARI Conference 2007

• Any Questions?
• Thank You

14
SPX Towers Design Conditions (3rd Selection)

• The student is requried to gain access to the SPX
  (Marley) web site at http//spxcooling.com/en/
• Click on the Design Conditions tab and fill in
  the following conditions
• Enter 200 GPM
• Enter Hot Water Temperature of 95 deg F.
• Enter Cold Water Temperaure of 85 deg F.
• Wet Bulb Temperature of 78 deg F.
• Numebr of Cells set to 2 cells
• Solve for Capacity
• 2 tolerance
• Fluid Cooler Requirements leave to none
• Free cooling/low ambiant options
• Maximum coil pressure drop default 25 psi

15
HVAC 462 Cooling Tower Objective

• What are the Students going to learn from the
  exercises?
• When this factor is REDUCED! The Tower Size
  is
•  
• GPM Decreased
• Approach Increased
• Wet Bulb Increased