Closetline® Packaged Water Source Heat Pump

CAS Units side by sideThe Closetline® CAS series from The Whalen Company boasts a compact cabinet, making this heat pump system the perfect solution for commercial retrofit or new construction applications.

The Closetline® CAS series far exceeds the ASHRAE 90.1 minimum efficiency and utilizes environmentally friendly refrigerant to reduce operating costs without compromising the environment. Closetline® water source heat pumps are popular in a variety of building applications where quiet operation in a compact footprint is a key requirement.

True to our commitment to offer equipment that’s flexible enough to meet the design of the building rather than forcing a building to conform to limitations of the equipment, our Closetline® packaged water source heat pumps can be applied to virtually any type of building.

With its compact footprint, the Closetline® CAS Series is particularly advantageous for new construction or renovation of apartments, condominiums, hotels, senior living facilities, dormitories and office buildings.


  • Benefits
  • How It Works
  • Technical Data
  • Literature

Compact Footprint

Compact cabinet design with quick access for ease of service. Horizontal units can be serviced through the unit bottom to virtually eliminate removing ceiling mounted units for service.

Fan Operation

Oversized blower for quiet operation. A PSC fan motor is standard for economical operation with an optional constant torque multi-speed EC motor, with soft start and serviceable from one side.

Drain Pan

Internally trapped (vertical models), stainless steel drain pan for years of trouble-free service.


Compact and efficient compressors, with double isolation for quiet operation.

Reliable Operation

Thermostatic expansion valve maintains maximum capacity under a wide range of operating conditions.

Coaxial Heat Exchangers

Heavy duty coaxial heat exchanger for reliability. Enhanced internal surface treatment for increased efficiency (CuNi available).

Easy to Install

Water connections are securely mounted flush to the cabinet to eliminate the need for a backup wrench.

Electronic Control Board

Each unit ships with solid state microprocessor controls with safeties built-in for reliable protection.

Built to Last

Satin galvanized and acoustically insulated cabinet for years of quiet operation.

Geothermal Application

Unit capable of operation on a closed loop or a water well installation.

Hot Gas Reheat Option

Hot Gas Reheat is used for humidity control and for occupant comfort. The integrated reheat coil is used to add sensible heat to the air stream to maintain the temperature setpoint and occupant comfort.


Heating Mode

In the heating mode (Figure 1), hot refrigerant flows through the air coil. The heat pump supplies warm air to the conditioned space. The heat added to the room air is removed from the water flowing through the coil, plus rejected compressor heat.

Whisperline fixed chassis packaged HP 01 heating

Cooling Mode

In the cooling mode (Figure 2), cold refrigerant flows through the air coil. The heat pump supplies cool air to the conditioned space. The heat removed from the room air is transferred to the water flowing through the water coil.

Whisperline fixed chassis packaged HP 01 cooling


Closetline® Horizontal Water Source Heat Pump

 Closetline CASH Technical Data1


Closetline® Vertical Water Source Heat Pump

 Closetline CASV Technical Data1