A heat pump system is capable of both heating and cooling a home. To achieve heating or cooling, the refrigeration cycle is reversed. In air conditioning mode, the system reduces the temperature of the air by absorbing the heat particles from the return air as it passes through the coils. A change of state within the refrigerant is what causes the absorption, as in cooling or release of heat in the heat pump cycle. An example of a change-of-state is when boiling water turns into steam (gas vapor) and returns to a liquid (water) as it cools.
- WARNING: Do not attempt to cool with an Air Conditioner (AC) or a Heat Pump (HP) if the outside air temperature is below 65ºF;
- After using the POWER switch to turn on your AC or HP, wait at least 24 hours before using the AC or HP;
- Never cycle quickly between heating and cooling;
- Do not block air vents (keep furniture away);
- Make sure the condensation drain line extends far enough away from the home to prevent water ponding and possible insect or water damage;
- Air handlers placed above finished ceilings should be equipped with overflow trays fitted with system shut-down float switches;
- Do not store toxic or hazardous items near the air handler, especially when located in the garage.
- Most AC systems are of the compressor-type, which have little maintenance that the typical homeowner is capable of performing. The homeowner, however, can remove any debris from around the outside coils, check the insulation on the exposed pipes, and change the air filter(s) monthly. Heat Pump systems should be professionally serviced every Spring before the cooling season and in the Fall before the heating season.
- A service contractor should be called in case of inadequate performance. The cooling coils should cool the return air by at least 15 degrees Fahrenheit. Call for service if the system is not cooling properly or if any peculiar noises are heard. Slow leaks in the refrigerant system may be a costly repair;
- The outside and inside coils should be serviced/cleaned regularly;
- Evaporative water-cooling systems found in the dry, southwest United States, require winterization in the Fall and prior to activation in the Spring. Periodic inspections are advised, especially after very hot weather or sand storms;
- The efficiency of a Heat Pump (HP) drops off as the heat source (air, water, soil) temperature drops. Below 40ºF, most manufacturers advise not to use the HP. This saves wear and tear on the unit and extends its service life. Some modern systems automatically turn on the electric or fossil fuel heaters and turn off the HP at a pre-set lower temperature. Manual systems require the thermostat to be switched to auxiliary or emergency heat function;
- Store mobile air conditioning units in the same orientation as when they are in use, not on their sides, back, top or front. Ensure proper condensation drainage.