Heat Pumps - Unitary Heat Pumps

Unitary heat pumps are factory-packaged refrigerant-based heat pumps that are available in a number of application categories which include:

• Packaged terminal heat pumps (PTHP)
  
• Closed water loop heat pump systems
  
• Ground source closed-loop heat pumps
  
• Ground water-source heat pumps
  
• Large unitary air- and water-source heat pumps
  
• In each category there are several possible configurations, including:
  
• Single package, with all components in a single enclosure
  
• Roof-top packages - a variation on the single package
  
• Split units, with remote outdoor coil, fan, and/or compressor
  
• Air and water-source heat pumps
  
• Heating only heat pumps
  
• Package units and the indoor sections of split units are available in several configurations:
  
• Vertical for closet installations,
  
• Console for installation under windows, and
  
• Horizontal for ceiling or outdoor locations.

Some models have decorative casings. Others can be built-in. With the exception of large unitary heat pumps, the units are designed for free-air delivery or with short duct connections between the unit and the conditioned space.

Most heat pump manufacturers participate in the Air-Conditioning and Refrigeration Institute (ARI) Certification Program. Product performance (below 135,000 Btuh sizes) is listed in the ARI Directory of Certified Products. This allows a performance comparison of various models from various manufacturers.

Sizes range from l/2-ton package terminal heat pumps up to rooftop units of 30-tons or more. Many are provided with supplemental electric heaters to satisfy the load when the outdoor temperatures drop below the set point. Gas fired supplemental heat is also available in a limited range of equipment. Most heat pumps are sold and installed by local air conditioning contractors, who also provide routine service and repair. Depending on the nature of the application, this availability of fast service can be very important in equipment selection.

Select from these areas of interest . . .