Definitions and Descriptions The definitions and descriptions are a primer so that you can understand the basics.  If you need an in-depth definition or explanation, please contact us. HVAC Systems standard HVAC = outdoor condensing unit + indoor furnace with evaporator coil heat pump system = outdoor unit + indoor air handler or furnace geothermal system = indoor unit with a water cooled condenser with evaporator coil unitary system = cooling and heating system in one unit that is outside of the structure absorption units = An HVAC system that uses chemicals rather then refrigerant to either heat or cool (normally commercial) HVAC Unit Types condensing unit - the unit that is placed outside the structure to supply air-conditioning.  This is used in conjunction with a furnace.  The coil that contains the hot refrigerant is always in the outside (condensing) coil and the cold refrigerant is always flowing through the inside (evaporator) coil furnace (gas-fired/electric) - this unit is located in the structure (attic, basement, crawlspace, garage, etc.).  It blows air across a coil and can add supplementary electric heat  to the air flow from a heat pump system. heat pump system - this system looks like a standard condensing unit/furnace HVAC system.  The difference in the two systems is that the heat pump system is designed to move the heated refrigerant to the indoor unit coil or to the outdoor coil.  Most heat pump systems have either an air handler or furnace on the inside of the structure for split systems.  It is also used in a unitary system. outside unit for a heat pump system - the outside unit looks like a condensing unit but has a reversing valve inside the unit.  This valve reverses the flow of refrigerant so that the hot refrigerant can flow through the coil inside or outside the structure. air handler - This unit is located in the structure (attic, basement, crawlspace, garage, etc.) and is part of the heat pump system.  The air handler blows air across a coil to the ducts.  It can have supplementary heat added to the air flow. geothermal system - This system uses a heat exchange to cool the refrigerant.  The water cools the refrigerant and the water becomes warmer.  Some times the water is circulated to warm the water in a spa or pool.  The water must be discharged outside the cooled residence. Unitary Systems unitary system - This HVAC system is a single unit that provides heat and cooling.  There are many combinations of system types to achieve this outcome.  unitary system = air-conditioner + furnace = heat pump system with an air handler or furnace = geothermal unit with an air handler or furnace through the wall or window unit - This is a type of unitary system.  It provides cooling and heat (normally electric heat) and is mounted in a wall or window. gas-pac - This is a type of unitary system with a gas- fired furnace for heat.  This unit is located outside the structure and is normally very large. swamp cooler - This unit adds water to the air to provide cooling through evaporation.  A swamp cooler is used in low humidity areas like the desert. HVAC Components accumulator - a container that collects liquid refrigerant so it will not travel to the motor- compressor. blower motor - a motor attached to a squirrel cage wheel that moves air.  This blower is normally used to blow air through the house ductwork.  It is used in a furnace, air handler, and unitary system. crankcase heater/sump heater - a heating element (normally a cartridge or encircling band on the exterior of the motor-compressor) that is located at the bottom of a motor-compressor. This heating element is used to keep the refrigerant in a vaporous state rather than a liquid in the oil. capacitor - a passive electronic component that stores energy in the form of an electrostatic field. In its simplest form, a capacitor consists of two conducting plates separated by an insulating material called the dielectric. Types and where used  - run capacitor: the motor-compressor - dual capacitor: a run and fan capacitor in one casing - fan capacitor: fan motor - blower capacitor: blower motor - start capacitor: motor-compressor during its start period only - “Super Boost”, “Booster” - a capacitor and relay device used with the motor-compressor when the repairer believes the motor-compressor is having difficulty starting.  This is normally a field installed item. capillary tubes - a group of small tubes that are used to convert the high pressure warm refrigerant into low pressure gas. coil - tubing that looks like a car radiator (condensing and evaporator or indoor and outdoor).  This tubing has other metal (fins) attached to the base tubing so that it can transfer heat rapidly.  This heat transfer is accomplished by a blower or fan passing air across the fins/tubing. fan motor - a motor that has prop (propeller) fan blades attached to the shaft.  Normally located in the outdoor unit.  The fan motor cools the refrigerant running through the exterior coil.  heat exchanger - a device  for transferring heat from one fluid to another without allowing them to mix. transformer - a device  to convert variations of voltage in a primary circuit into variations of voltage and current in a secondary circuit.  In HVAC systems there is normally a low voltage transformer which usually transforms the electricity from 240 volts or 115 volts to 24 volts. relay - an electromagnetic device that is actuated by variation in conditions of an electric circuit.   The relay operates other devices in the same circuit or a different circuit.  It is like an automatic switch. cylinders - cylindrically shaped holes in the compressor body that allow the piston to travel up and down in the cylindrically shaped hole. pistons - a cylindrically shaped piece of metal that is attached to a connecting rod.  The piston travels up and down in the cylinder (cylindrically shaped hole) to compress the refrigerant. muffler assemble - this is an area that the refrigerant travels to dampen the sounds generated by the motor-compressor. solenoid - an electrical device that carries a current that acts like a magnet.  When current flows through the solenoid coil, the  movable core is drawn into the coil and is used to operate a valve which controls a device.  In a heat pump system the solenoid controls whether the indoor or the outdoor coil contains the hot refrigerant. windings - bundles of wires that are threaded through a stator to create a motor. Water Moving Systems irrigation pump - a system normally consisting of a pump and motor that move large volumes of water for irrigation purposes.  These  irrigation well pump can be very large. submersible well pump and motor - a motor that is attached to a pump and placed inside a well casing.  When the motor is energized, the pump rotates causing the water to flow up a pipe.  The water normally flows into a tank that has a pressure switch that turns the motor on and off. well casing - the plastic or metal tubing which forms the sides of the well.  It is used to hold the dirt away from the hole. grinder pump - a pump and motor system that incorporates a grinder in the system.  This grinder is used to grind waste material so that it can be pumped to a different location. This marketing introduction describes some of our expertise. For more information, comments or questions, please contact us. 1.866.451.5438, contact form, or office@aceForensics.com