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HVAC Design Solutions - Frequently Asked Questions (FAQ's)

(Click on "hyperlink" to see response to questions)

  1. What is your new "62.1-2013 Comply-VAV" program and how does it work with ASHRAE Standard 62.1-2013?
  2. What is the "Basic Project Input Sheet", and why is it linked to all the other calculations?
  3. What makes your "Enhanced Equal Friction" Duct Calculator better than the typical duct calculator wheel or sliderule?
  4. Why do you call your duct sizing program "Simplified" Static Regain? Isn't static regain sizing pretty complicated and tedious?
  5. Does the "Fan Static Pressure Calculations" Program include all possible types of duct fittings? Does it use actual duct fitting loss "Coefficients" like ASHRAE or SMACNA, or does it use equivalent lengths for fitting losses?
  6. What's included in the "Information Request Letters and Forms"? What's their purpose?
  7. What makes your "Pipe Sizing -Optimum Economic Sizes" Programs better than the typical circuit sizing wheel or pipe sizing charts?
  8. What are the "HELP" buttons on most of the Programs? (In the upper right corner of the sheet)
  9. How does your "Water Pipe Sizing" Program calculate the maximum allowable pipe pressure drop (PSIG/100 ft.)?
  10. What rainfall rates are the "Horizontal Roof Drainage Piping" Programs based on?
  11. Are the "Natural Gas Sizing" Programs based on typical "length versus cubic feet per hour (CFH)" tables?
  12. Does the "Water Heater Sizing Calculations" Program adjust the Demand and Storage Factors for various types of facilities?
  13. What's the difference between "Peer Review" and "Quality Control Checking"?
  14. Why are there so many pages in the "Mechanical Plan Review" Section? Doesn't that make the process pretty cumbersome?
  15. Why is there so much information in the "Plumbing Plan Review for Underground Floor Plans"? It appears that there is a lot of information required from the floors above to check the Underground Plumbing Plan?
  16. What is the "Conversion Program" that's listed under Miscellaneous Design?

 

HVAC Design Solutions - FAQ Responses

  1. What is your new "62.1-2013 Comply-VAV" program and how does it work with ASHRAE Standard 62.1-2013?
  2. Our "62.1-2013 Comply-VAV" Software Package incorporates all of the ASHRAE "Ventilation Rate Procedure" formulas, tables, and directives.  Our program greatly simplifies the compliance process by automatically performing many of the complex calculations, with minimal input from the User (Typically only 6 to 8 input items per zone).

    An important feature of our programs is the proprietary "Optimization Procedure" which can be used to assure that the required Outdoor Air Volume is established, while avoiding the potentially excessive Outdoor Air Volume that could be dictated by standard calculations.  "Optimization" of the Outdoor Air requirements can mean a significant saving in Energy and Operating Costs over the life of a system.

    Compliance Documents can be printed after completing the calculations and can be submitted as a compliance record to the appropriate Building Department or Code Authority, along with the project construction documents.

  3. What is the "Basic Project Input Sheet", and why is it linked to all the other calculations?
  4. The "Basic Project Input Sheet" should be the first Form to be completed on each Project. Information that is inserted in this Form is automatically transferred to other programs for use in calculations and for documenting project data. The information you input into this form is transferred to other Programs and Forms when you open the desired Program and select "Enable Macros" and then select "Update Links". For instance, once you have replaced "Your Company Name" at the top of the Form with your actual Company Name, it will appear at the top of each form and will be included when a hard copy of the file is printed.

    These values are also Locked in the Programs so they can't be accidentally changed. If you need to change any of the data, you should return to the "Basic Project Input Sheet" to make the changes, and then "Save" it again.

  5. What makes your "Enhanced Equal Friction" Duct Calculator better than the typical duct calculator wheel or sliderule?
  6. Our "Duct Sizing Calculator - To Avoid Obstructions" uses a modified equal friction sizing procedure, including velocity reduction at larger air quantities. In addition our "Enhanced Equal Friction Duct Sizing" incorporates "Duct Sizing to Avoid Obstructions" (such as beams) in the ceiling space. The program also includes Yellow or Red warning "Flags" if the space below the beam is too small and would result in duct sizing that exceeds recommended aspect ratios. Additionally, the Duct Sizing calculations select the most economical duct sizes to fit within the available space.

    The typical duct calculator wheels give a wide range of possible sizes and it is left to the Designer to pick one of the many possibilities. Depending on the experience of the Designer or the time available for duct sizing, the selection of duct sizes could result in ducts that won't fit in the space (which can lead to Change Orders!). Also, the ducts could be significantly more expensive to install and also to operate (increased horsepower) than optimum sizing.

  7. Why do you call your duct sizing program "Simplified" Static Regain? Isn't static regain sizing pretty complicated and tedious?
  8. Yes, Static Regain duct sizing CAN be quite complicated and tedious. Duct sizes are adjusted so that the static regain (due to velocity reduction) in each section of ductwork will offset the static pressure losses due to duct friction and fitting losses. The advantages of using Static Regain sizing include a potentially significant reduction in air balancing requirements for the system. Static Regain sizing is often utilized for supply duct mains, while branches and runouts are sized by Equal Friction.

    We call the program "Simplified Static Regain Duct Sizing" because the design process has been reduced significantly from conventional Static Regain Sizing. Please refer to the typical ductwork sketch in the description of the "HVAC Airside Design" Package. All that's required for "Simplified Static Regain" sizing is to input the "Initial Velocity of First Duct Section from the Fan", input the "Air Quantity" at each duct section, input the "Space Below Beams" at each duct section, input the "Measured Length" of each duct section, and count the various fittings for each section. That's it! "Simplified"!

    This "Simplified Static Regain Duct Sizing" Program reduces the time and effort required to use Static Regain sizing, by performing the numerous iterations that are required to match static pressure regain with static pressure losses. In addition, "Simplified Static Regain Duct Sizing" incorporates "Duct Sizing to Avoid Obstructions" (such as beams) in the ceiling space.

  9. Does the "Fan Static Pressure Calculations" Program include all possible types of duct fittings? Does it use actual duct fitting loss "Coefficients" like ASHRAE or SMACNA, or does it use equivalent lengths for fitting losses?
  10. No, the program does not include "all possible types" of duct fittings in the database. However, it does include all of the typically used fitting types and configurations, and it does incorporate the duct fitting loss "Coefficients" from many sources, including ASHRAE, SMACNA, Trane, and Carrier.

  11. What's included in the "Information Request Letters and Forms"? What's their purpose?
  12. The Information Request Letters and Forms include two Building Internal Load Information request letters, a Ceiling Space Information request letter, a Heating/Cooling Load Design Criteria Form, and three various Load Calculation Take-off Forms. The "Building Mechanical Information Request" letters should be sent to the Building Owner, Facility User, and/or Project Architect for their input regarding Mechanical system loads. The Information Request Letters and Forms are intended as "Programming" tools, to determine anticipated usage and internal loads of all Rooms in the Project.

    An important benefit of sending the Information Request Letters to the Owner or Facility User is that it involves them in the Design of their Facility. Improved Owner/Design Team/Construction Team relationships can significantly increase the Owner's satisfaction with Your Project.

  13. What makes your "Pipe Sizing -Optimum Economic Sizes" Programs better than the typical circuit sizing wheel or pipe sizing charts?
  14. The typical circuit sizing wheels recommend that sizing should be based on a maximum friction rate, and it is left to the Designer to select the sizes on that basis. Depending on the experience of the Designer or the time available for pipe sizing, the selection of pipe sizes could result in excessive velocities that lead to noise or erosion problems. If the velocity is too low, this can lead to air trapping problems. Also, the pipes could be significantly more expensive to install and also to operate (increased horsepower) than optimum sizing.

    The "Pipe Sizing - Optimum Economical Sizes" Programs use a combination of velocity and pressure drop, and include recommended ranges of velocity and pressure to avoid erosion and air trapping problems. In addition, "Pipe Sizing - Optimum Economical Sizes" Program includes pipe size selections that range from "Lower First Cost" to "Lower Operating Cost". This allows alternate size selections with economic trade-offs. The Program also includes Red, Yellow, or Orange warning "Flags" if the alternate size selection would result in excessive velocity, too low velocity, or excessive pressure drop.

  15. What are the "HELP" buttons on most of the Programs? (In the upper right corner of the sheet)
  16. The "HELP" buttons are hyperlinks to Help Files that describe the particular Program, describe how to use the program, what values to input into the program, and how to interpret the results of the calculations. The Help Files range from one or two pages to six pages or more. All Help Files can be printed out for permanent Reference.

  17. How does your "Water Pipe Sizing" Program calculate the maximum allowable pipe pressure drop (PSIG/100 ft.)?
  18. Maximum allowable pipe pressure drop (PSIG/100 ft.) is based on the available water pressure from the "street main" and the pressure requirement of the most remote fixture on the system. To determine the pressure available for pipe losses, it is necessary to deduct the pressure losses for all of the known devices and accessories in the water service, including the Water Meter, Backflow Preventer, Pressure Reducing Valve, and Water Filter or Water Treatment Equipment, as applicable. Also, the loss of pressure due to static height of the highest fixture is deducted from the "available water pressure". The final "Water Pressure Available for Piping Loss (PSIG)" is then applied to the "Total Developed Length of the Longest Pipe Run" to determine the "Maximum Allowable Pipe Pressure Drop (PSIG/100 ft.)" for Pipe Sizing.

    To determine an accurate "Total Developed Length of the Longest Pipe Run", the "Preliminary Water Pipe Sizing Schedule" Program is used. It is NOT good practice to measure the longest pipe run and "add 50% for fittings", which can result in over-sized or under-sized pipe systems. To obtain a significantly closer estimate of the "Total Developed Length", the "Preliminary Sizing Schedule" is completed and the resulting "Total Fitting Equivalent Length" is added to the actual Measured Length (horizontal and vertical) of the "Longest Pipe Run". This corrected value is then input into the "Water Pipe Sizing Calculations" Program. This will adjust the "Maximum Allowable Pipe Pressure Drop" to a more accurate value. This new "Maximum Allowable" is automatically transferred to the "Preliminary Water Pipe Sizing" Program, which automatically calculates a new "Total Fitting Equivalent Length". This new Equivalent Length is applied to the Measured Length in the "Water Pipe Sizing Calculations" Program to arrive at an even more accurate "Maximum Allowable Pipe Pressure Drop". After a couple of iterations, it is not necessary to repeat the process, because the "Maximum Allowable Pressure Drop (PSIG/100 ft.)" will not change significantly. The final result is an accurate "Allowable Pressure Drop" figure to use for the Water System Pipe Sizing.

  19. What rainfall rates are the "Horizontal Roof Drainage Piping" Programs based on?
  20. The "Rainfall Rate for 100 Year, 60 Minute Duration Storm in Local Area (Inches/Hour)" should be based on the Local Weather Bureau Data, from Locally Adopted Building Codes, or from publications such as National Oceanic and Atmospheric Administration (NOAA). If State or Local Codes require a more conservative sizing basis than the 100 Year, 60 Minute Storm, the required Rainfall Rate can also be used with these Programs. Any Rainfall Rate can be used with these Programs, since the calculations are based on formulas, not on specific charts of various rainfall rates.

  21. Are the "Natural Gas Sizing" Programs based on typical "length versus cubic feet per hour (CFH)" tables?
  22. No, the "Natural Gas Pipe Sizing Schedules - Low Pressure and - High Pressure" Programs use a combination of measured lengths, valve and fitting pressure drop factors, and NFPA Formula or Weymouth Formulas to determine accurate pipe sizes. This eliminates the usual interpolation required when using the Tables. In addition, the "Natural Gas Sizing" Programs include pipe size calculations that are based on "Maximum Allowable Pressure Drop" for the longest run of piping. This helps to assure that the available gas pressure will be adequate to provide the required pressure at the most remote gas furnace or appliance.

  23. Does the "Water Heater Sizing Calculations" Program adjust the Demand and Storage Factors for various types of facilities?
  24. Yes, the "Water Heater Sizing" Program includes a "Drop-down List" of several types of facilities, for the User selection. This selection automatically adjusts the Demand and Storage Factors to values recommended by nationally recognized organizations such as ASHRAE and ASPE, as well as, by typical Plumbing Codes.

  25. What's the difference between "Peer Review" and "Quality Control Checking"?
  26. "Peer Review" and "Quality Control Checking" are actually synonymous, as used with this Process. We have used the term of "Peer Review" because the Programs and Checklists were written as, and should be used as a "disinterested" outside Consultant that is reviewing your Project. By approaching the Review process as an "outsider" or Peer, it is more likely that most Errors and Omissions that may have slipped by during Design and Drafting will be eliminated. Also, as an "outsider" it is easier to check on Coordination Between Disciplines, to uncover Constructability Problems, and help discover and eliminate questions and discrepancies that may come up after a Construction Contract has been signed.

  27. Why are there so many pages in the "Mechanical Plan Review" Section? Doesn't that make the process pretty cumbersome?
  28. As you can see from the "Table of Contents" and "Examples" pages, the "Mechanical Peer Review" Package is intended to be all-inclusive and to cover most of the types of Projects that are associated with HVAC Engineering. The "Mechanical Plan Review" Section is organized by Plan Types, such as "Legend and Symbols Sheet", "Schedule Sheets", "Mechanical Ductwork Floor Plans", etc. The "Schedule Sheets" are further organized alphabetically by "Equipment Type", with hyperlinks to each Equipment Schedule checklist. The "Mechanical Detail Drawings" are arranged by "Type of Detail" and also alphabetically, and also have hyperlinks to the Detail checklist.

    With the "logical" organization and extensive hyperlink navigation, the review items are relatively easy to use and provide a very thorough Review of most HVAC Projects.

  29. Why is there so much information in the "Plumbing Plan Review for Underground Floor Plans"? It appears that there is a lot of information required from the floors above to check the Underground Plumbing Plan?
  30. It's true that the "Plumbing Underground Plan" includes a significant amount of work on the floors above, to determine the actual loads on the underground pipes. This is a typical part of the Plumbing Design process, and the Review Checklist Items basically follow the process to assure that all items have been taken care of properly. The extra work that is required for checking the Plumbing Underground will reduce the work required when the floors above are checked.

  31. What is the "Conversion Program" that's listed under Miscellaneous Design?

The included "Conversion Program", Convert.exe is a Freeware Program that can be used to convert many units from one type system to another, such as English Units to SI Units. The program includes tabs for the various categories, such as Temperature, Volume, Mass, Pressure, Power, Distance, Flow, Area, Acceleration, etc. After selecting the category tab, the desired "Input Units" such as "Gallons Per Minute (GPM)" and the desired "Output Units" such as "Liters Per Minute (LPM)" are selected. When the GPM value is input, the converted LPM value is displayed. The program can also be "Customized" to add other conversions.

Note that there is no guarantee that the program will work for all conversions. The Convert.exe program is provided "as is" and the author or any distributor can not be held responsible for any damage that might occur by using the program, or for any information contained in the program.

 

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