Heat Pump Classifications

There are multiple classifications to consider when choosing the right heat pump for you. The source of where you will be transferring the heat from is the first.
In addition, heat pumps may be equipped with either digital or analog controls. And finally—regardless of their heat source or control type—heat pumps may be of the heat-only variety, or may be capable of both heating & cooling (sometimes called: Reversing models…AquaCal^® labels these units under the ICEBREAKER^® brand).

The term Source refers to where the heat pump derives its heat:

• Air Source heat pumps get their heat from the outside air. This is the most common type of heat pump.
• Water Source heat pumps get their heat from water. The water may come from a well, lake, stream, or any body of water sufficient in size to provide the amount of heat required to reliably heat the pool or spa. Closed loop systems—using the ground water or a water tower for heat—are other water source possibilities.

Control systems are divided into two types: Digital and Analog. The most common type now is Digital.  The following statements are specific to AquaCal^® products:

• Digital control systems maintain water temperature within .8ºF of set point (field programmable from .2 to 2°F). In addition to close water temperature control, digital controllers offer enhanced defrost capabilities, allowing digitally-controlled units to operate in lower ambient conditions than their analog-controlled counterparts. And finally, digital systems—because of their self-diagnostic capabilities—are extremely easy to troubleshoot and maintain. Primary components are:
  • Digital printed circuit (PC) board. In addition to temperature control, defrost and numerous operational safety parameters are monitored and controlled by this PC board;
  • A water temperature sensor; and,
  • A combination digital display and key-style input board.
• Analog control systems maintain water temperature to within approximately 2ºF of set point. Primary components are:
  1. An electronic printed circuit thermostat board;
  2. A water temperature sensor; and,
  3. Knob-equipped water temperature user adjustment point.

• Heat-Only heat pumps are capable of, as the name implies, heating only.  Additionally, all heat-only heat pumps are equipped with passive defrost systems, meaning that these heaters will shut off when conditions are such that frost and ice begins to form on their evaporator surfaces.
• Heat & Cool (reversing) heat pumps can both heat and cool pool and/or spa water. The AquaCal^® brand name for these heaters is ICEBREAKER^®.  Heat & Cool heat pumps are equipped with active, hot gas defrost systems, permitting them to continue to operate successfully at temperatures much below other heat pumps equipped with traditional passive defrost systems.