Hydronic Vertical Unit Heaters

Sterling VS Series vertical unit heaters are designed for installations requiring down flow air delivery. Offered in 15 sizes ranging from 41,300 to 705,000 BTU. Low output (increased airflow) units are available for high ceiling applications, steam or hot water operation.

Standard Features

  • 35 - 705 MBH
  • Copper Coils w/Aluminum Fins
  • Totally Enclosed Motors
  • Standard Units are Field Convertible to Low Output by Removing Airport Knockouts Located on Top of the Unit
  • Thermal Overload Protection
  • 4-Point Suspension


The unit casing is formed by two square, 20-gauge steel plates. The bottom plate forms an orifice for air delivery. Air
ports are stamped in the top plate of standard units for easy conversion of low output units

  • The aluminum blade fans are quiet, factory balanced and sturdy for standard or spark proof applications.


Standard motors are 115/60/1, totally enclosed, with thermal overload protection for all vertical units through size 285. Standard motors for sizes 40, 62 and 77 are shaded pole, sleeve bearing. The vertical 104 motor is permanent split capacitor type with sleeve bearings. Motor for unit sizes 125 through 285 are permanent split capacitor types with permanently lubricated ball bearings. Motors used on unit sizes 317 through 700 are 230/460/60/3, totally enclosed, with permanently lubricated ball bearings. Unit sizes smaller than 317 are also available with 230/460/60/3 motors.

All motors fractional HP and integral HP, have Class “B” insulation. The 115/60/1 motors used as standard on unit sizes 40through 104 can be operated at multiple speeds with the addition of a solid-state control.


    All the Literature associated with the VS SERIES


    For additional items browse the full Literature library at the link below.


    Performance, Materials and Features for each VS SERIES capacity model.


    Standard Unit (min)

    Low Output Unit (min)

    Standard Unit (max)

    Low Output Unit (max)

    MBH Input41 MBH35 MBH705 MBH620 MBH
    MBH Output41 MBH35 MBH705 MBH620 MBH
    Min CFM598 CFM668 CFM598 CFM668 CFM
    Max CFM11,000 MBH11,900 MBH11,000 MBH11,900 MBH


    Motor HP1/40-31/40-31/40-31/40-3


    The VS SERIES is quite versitile it can be installed in a variety of applications. Here are a few key ways The VS SERIES can make your space more comfortable.

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