Custom Air Handling Units | Preliminary Design Questions That Are Asked

Every Custom Air Handling Unit starts with a list of design parameters that must be answered.  If these items are explored and discussed early on it makes for a significantly better design.  Here are the key items that we look for in preliminary Custom Air Handling Unit design.

Lowell General - Air Enterprises Unit AssemblyProject Scope:

  1. Description of application – what will the unit be used for?
  2. What is the budget reality;  Energy efficient unit or low first cost?
  3. Project timeline –  is this a fast track job?

Physical Data:

  1. Indoor or outdoor unit?
  2. Factory or Field built?
  3. Are there design constraints?
    1. Dimensions
    2. Weights
    3. Access
    4. Rigging
  4. Construction Materials
    1. All Aluminum Construction?  Stainless Steel Interior Sections?
    2. Architectural Considerations – Special Coatings?

Lawrence Hospital - All Aluminum Air Enterprises UnitOperational Data:

  1. Unit Type:
    1. Constant Volume (CV) or Variable Air Volume (VAV)?
    2. Standard Unit or Energy Recovery?
    3. 100% Outside Air (OA) or Mixed Air
    4. Draw through or Blow through
  2. Components
    1. Cooling Type (Chilled Water, DX or Heat Pump)
    2. Heating Type (Hot Water, Steam, Gas or Heat Pump)
    3. Filters;  pre & final filters, HEPAs, carbon filters?
    4. Humidification – steam, adiabatic?
    5. UVC lighting?
    6. Lighting package?
    7. Controls package?
    8. Testing?
  3. CambridgeportDesign Parameters
    1. Design Volumes
      1. Supply CFM
      2. Return CFM
      3. Minimum Outside Air (OA) CFM
      4. Exhaust CFM
    2. External Static Pressures
      1. Supply
      2. Return
    3. Design Temperatures and Conditions – both summer and winter
      1. Outside Air (OA) db/wb
      2. Return Air (RA) db/wb (space condition)
      3. Supply Air (SA) db/wb

 This is a start. These are base questions that begin the process.  There are 100’s of options on Custom AHU’s.   If more information is provided in early stages of design,  the process moves quicker and unit design is significantly enhanced. 

Related Blog Posts: 
Custom Air Handling Units | 5 Reasons to use Custom Air Handling Units

Field Erected Air Handling Units | 4 Good Reasons to Assemble an Air Handling Unit On-Site

Custom Air Handling Units | 5 Reasons to use All Aluminum Construction

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