Hot Water Coil

Quality replacement hot water coils to fit your exact needs for new equipment or replacement.

Hot Water Coil Information

Hot water coils are heat exchangers used to heat air streams, and are at the heart of your heating system. The coils consist of rows of tubes that pass through sheets of formed fins. As cold air passes through the coils, heat transfers from the hot water flowing through the tubes to the air in the coil.

Replacement hot water coils are our top-selling product, because they are widely used in commercial applications and need to be replaced quickly should they fail. Hot water coils are used for a variety of applications, including preheating, reheating, comfort heating, booster heating, waste heat reclamation, and fluid process heat.

We custom build replacement hot water coils for your exact situation. Simply give us the specs or let us help you figure out what you need, and we’ll arrange a delivery schedule that works for you.

Brands We Can Replace:

  • Carrier
  • Trane
  • Heatcraft
  • Colmac
  • McQuay
  • Other Manufacturers


  • Duct Mouted

    We commonly replace duct mounted coils (sometimes called booster coils) in commercial buildings with large occupancy space and onsite boilers.

  • Inside Air Handling Units

    We can build an exact replacement of an original equipment manufacture (OEM) coil for a fraction of the price.

  • Other hot water coils

    Even if the type of hot water coil you need isn’t listed above, we can probably build the exact coil you need. Give us a call at 1-855-Coil-Now.

Hot Water Coil Design

Hot water coils are used to heat air streams. Air moves through the fin contact area, and hot water (usually around 180 degrees Fahrenheit) moves through the tubes.

Some typical applications for hot water coils:

  • Comfort Heating
  • Preheat
  • Reheat After Dehumidification
  • Boosting Air Temperature in Long Duct Systems
  • Fluid Process Heat

Hot Water Coils come in a variety of shapes and sizes, but there are some properties that are common in most hot water coils:

  • Rows

    With hot water coils operating at high temperatures (typically 120-180 degrees Fahrenheit), we commonly see 1 or 2 row hot water coils.

  • Tube Diameter

    5/8 inch tube diameter is the most common selection for hot water coils. This tube size is perfect for minimizing fluid pressure drop while maintaining heat transfer. 5/8 inch tubes also offer many wall thickness options, which can increase the coils’ lifespan before tube erosion becomes a problem.

  • Connections

    Connections for hot water coils are typically MPT (Male Pipe Thread) and made of copper. Smaller coils may use copper sweat connections. Grooved connection types are becoming increasingly popular, and are available upon special request.

Hot Water Coil Specifications


Constructed from UNS 12200 seamless copper while conforming with ASTM B75, ASTM B88 and ASTM B251d

  • 5/8" diameter
    • 0.020", 0.025", 0.035", or 0.049" wall
  • 1/2" diameter
    • 0.017", 0.025", or 0.032" wall


All fins feature continuous die formed construction

  • 5/8" x 1.500" x 1.299" pattern
    • Waffle, flat corrugation, sine,
    • H1100 aluminum, C12200 copper, stainless
    • 0.0060", 0.0075", or 0.0100" thickness
    • 4-14 fins per inch
  • 1/2" x 1.250" x 1.083" pattern
    • Waffle or flat corrugation
    • H1100 aluminum or C12200 copper
    • 0.0060", 0.0075", or 0.0100" thickness
    • 4-14 fins per inch
  • 3/8" x 1.00" x 0.866" pattern
    • Waffle, flat corrugation, sine, louver
    • H1100 aluminum or C12200 copper
    • 0.0060", 0.0075", or 0.0100" thickness
    • 4-22 fins per inch


Constructed from UNS 12200 seamless copper while conforming with ASTM B75, ASTM B88 and ASTM B251d

Optional vents and drains for manual venting and drainage

Headers range from 0.75" nominal diameter (0.875" outside diameter) to 5" nominal diameter (5.125" outside diameter)


  • MPT (Male Pipe Thread)
    • Copper (Type "L")
    • Steel (Schedule 40)
    • Red Brass
  • FPT (Female Pipe Thread)
    • Copper (Type "L")
  • Sweat
    • Copper (Type "L")
  • Victaulic
    • Steel (Schedule 40)


  • 18,16,14,12,10 gauge
    • Galvanized Steel (G90)
    • Stainless Steel (304)
    • Stainless Steel (316)
    • Aluminum (H11)

Hot Water Coil Performance

Coil performance varies greatly from application to application. Flow rates and temperatures for both fin and tube sides will greatly influence the performance characteristics for any given coil.

We have state of the art software that we can use to quote performance. For a detailed performance run tailored to your situation, please email with as many of the following details as you have available:

  • Coil model number
  • Duct size
  • Air Flow Rate in CFM (cubic feet per minute)
  • Entering Air Dry Bulb Temperature in °F
  • Entering Air Wet Bulb Temperature in °F (cooling coils only)
  • Fluid flow rate in GPM (gallons per minute, for water coils only)
  • Entering fluid temperature in °F
  • Desired capacity in MBH or tons
  • Desired leaving air temperature in °F

Sizing Guidelines

Blank Drawings

Related Applications:

Replacement Coil