Understanding Your Heating and Cooling System Seem Complicated?
Browse our glossary below to get a better understanding of components and services related to your heating and cooling system.
An air handler, or air handling unit, is the indoor part of an air-conditioning or heat pump system. Air handlers work much like furnaces in that they efficiently move air throughout the home. The main difference is that the air handlers only circulate heat when paired with a heat pump.
Boilers are special-purpose water heaters. While furnaces carry heat in warm air, boiler systems distribute the heat in hot water, which gives up heat as it passes through radiators or other devices in rooms throughout the house. The cooler water then returns to the boiler to be reheated. Hot water systems are often called hydronic systems. Residential boilers generally use natural gas or heating oil for fuel.
Chillers use a refrigerant gas to move the unwanted heat between the evaporator and the condenser. The chilled water is generated in evaporator and this is sent around the building by a pump to collect the unwanted heat and bring it back to the evaporator to be cooled down. The refrigerant collects this heat and moves it to the condenser. The condenser puts this unwanted heat into another loop which is sent by a pump to the cooling towers to send it into atmosphere or it will send it to a cooling coil where a fan blows the heat away, much like you blow onto a hot spoon of soup to cool it down.
The typical operation of a fan condenser unit is to transport air from the outdoor across a condensing coil. As that process is achieved, the condensing coil transfers heat to the air which allows the refrigerant to condense from a gas back to a liquid form. The primary job of the condenser motor fan is to provide enough torque at a reliable and constant level so that the fan can properly pull air into the unit and through the condensing coils. All of the moving parts come together to achieve one function, which essentially is to move heat from one place to another location.
A dual-fuel system is a home comfort system that pairs an electric heat pump with a gas furnace and alternates between the two fuel sources to maximize comfort and efficiency. A dual-fuel heat pump works in conjunction with a furnace. During the summer months, the heat pump works like a high-efficiency central air conditioner. In mild spring and fall weather, it provides cost-effective and efficient heat. As the temperatures drop in the winter months, the pump shuts off and lets your furnace take over.
An evaporator coil is the part of an air conditioner or heat pump that absorbs the heat from the air in your house. It is located inside the air handler or attached to the furnace. Located inside the blower compartment or air handler, the evaporator coil holds the chilled refrigerant that the compressor moves into it. As the air from the blower fan moves over the coil, the cold refrigerant removes the heat from your home’s air. The refrigerant becomes warmer and travels to the condenser coil outdoors.
A fuse is an electrical safety device (a component) that removes electrical current from an electrical circuit when the current in the electrical circuit is too high. A fuse is a length of wire that melts (breaks or blows) when the current through it is above a certain level – the fuse rating. The 'fuse rating' is the electrical current that will blow the fuse, for instance 3 amps, 10 amps or 13 amps.
A heat pump is an all-in-one heating and air conditioning system that works year-round to keep you comfortable. During warmer months, a heat pump works as a normal air conditioner. It extracts heat from inside the home and transfers it to the outdoor air. In colder weather, however, the process reverses—the unit collects heat from the outdoor air and transferring it inside your home.
Mini splits have two main components: an outdoor compressor/condenser, and an indoor air-handling unit. A conduit, which houses the power cable, refrigerant tubing, suction tubing, and a condensate drain, links the outdoor and indoor units.
In simplest terms, today’s hydronic heating is an energy efficient home heating system that uses tubing to run a hot liquid beneath the floor, along base board heaters, or through radiators to heat your home. Also referred to as radiant heating.
Flushing linesets is a preventative measure taken against possible contamination after R-22 to R-410A conversions and acid burnouts. Replacing linesets is of course the preferred method of preventing side effects of residual contamination but at times a full replacement may not be practical or affordable.The best service practice is to remove the linesets altogether along with the system components. However, in many cases this may be impossible or cost prohibitive when linesets are under concrete or recessed in walls. Therefore, technicians have no choice but to clean the linesets.
The Seasonal Energy Efficiency Ratio (SEER) relates to how much energy—and money—an AC unit will use in operation over the course of one year. The number lets homeowners compare one system to the next and understand which is more efficient.
A smart thermostat is responsible for controlling your home’s temperature. As with many smart devices, smart thermostats connect to your home network, giving you remote access and control over all the device’s functions.These smart devices differ slightly from their programmable counterparts. The latter can merely be set to turn on or off at select times. A smart thermostat, by contrast, not only allows for easy scheduling and management but also studies your behaviors and adjusts settings accordingly.
A variable-speed motor is a component of high-performance residential furnaces and air handlers. Connected to fan blades, it moves air through your ductwork and into the different rooms of your home.
Unlike single-speed motors that run at full capacity and then cycle off, a variable-speed motor can operate at high speeds, low speeds or anywhere in between, ramping up and down like a dimmer switch. Because it can fine-tune airflow to heating or cooling demand, it minimizes wasted electricity and ensures money spent on utility bills goes directly into the comfort of your home.
A wireless thermostat—also called a WiFi thermostat, digital thermostat or Internet thermostat—is a home automation device that regulates temperature. The best WiFi thermostats contain sensors which control the heating and cooling systems within houses, apartments or businesses. A WiFi thermostat works in conjunction with your heating, ventilation and air conditioning (HVAC) system. While a standard thermostat acts as a control panel for your home's heating and air conditioning system, a programmable thermostat can be adjusted from a remote location. Schedule temperatures that correspond with when you are sleeping, waking up, away from home and back in the house again. Simply select your own cooling and heating preferences based on your energy savings goals.
A blower motor is the component within a home’s HVAC system. The motor blows heated air through vents when the heating system is in use. Conversely, some blower motors blow cold air when the air conditioning system is in use. There are two main types of blower motors: single-speed motors and variable-speed motors. Single-speed blower motors blow air at one speed. Variable-speed motors adjust their speed to blow air at varying speed levels. A properly functioning blower motor remains a critical component of your home’s HVAC system. The blow motor is vital in maintaining a comfortable temperature within your home.
Motors used in HVAC such as the condensing fan motors or blower fan motors sometimes need help to get moving and to stay running at a steady pace, with no heavy up and down spikes. To do this HVAC units use what are called Start and RUN capacitors.The Start Capacitor gives a fan motor the torque it needs to start spinning then stops; while the Run capacitor stays on giving the motor extra torque when needed.
An AC or heat pump compressor is the part of an outdoor air conditioner or heat pump that compresses and pumps refrigerant to meet household cooling requirements. How it works: The compressor in the air conditioner or heat pump circulates refrigerant. Refrigerant absorbs and releases heat as it travels between the indoor and outdoor units, helping to maintain a cool and comfortable indoor temperature.
Ductwork refers to the system of ducts (metal or synthetic tubes) used to transport air from heating, ventilation and air-conditioning (HVAC) equipment throughout your home. Properly installed and well-maintained air ducts are a key component of indoor air quality and home comfort.
A furnace heat exchanger is the part of your furnace that is responsible for keeping your breathing air and the combustion process separate. This is absolutely essential to prevent carbon monoxide poisoning. A furnace heat exchanger begins at the burner assembly of the furnace, and goes to the spot where the chimney vent connects with the furnace. This passageway, combined with a metal chamber, allows for the safe distribution of heated air throughout your home. A furnace heat exchanger works by literally exchanging (or transferring) the heat created in the combustion chamber to the exterior of the unit, where it is then blown through the ductwork throughout the house.
Higher SEER numbers indicate higher efficiency. The minimum SEER rating is 13, with a rating above 16 considered high efficiency. Newer air conditioners incorporate features like more efficient compressors, improved heat exchange coils and high-efficiency blowers to increase overall system efficiency and reduce energy costs.
PTAC stands for packaged terminal air conditioner. PTACs are single, commercial grade, self-contained units installed through a wall and often found in hotels. A PTAC's compressor system both cools and heats. To cool, the units compressor pumps refrigerant to cool the coils which attracts heat and humidity which is then exhausted to the outside. To heat, this functionality is reversed. The refrigerant is used to heat the coils, and when air passes over it the unit pushes the heated air into the room. PTACs are larger than a typical through-the-wall air conditioner; the standard size is 42 wide. PTACs are often seen in the hospitality industry and are approved for commercial use, but they are also suitable for residential applications.
Air conditioning systems rely on movement and the change of state (evaporation and condensation) of refrigerants between an outdoor condenser coil and an indoor evaporator coil. The lines that carry the refrigerant between the evaporator and condenser coils and through the compressor and expansion device typically are copper. The larger line typically carries a cool gas and is insulated. This is commonly referred to as the suction line, but it is also called the return line or vapor line. The smaller uninsulated line typically carries a warm liquid. It is most often called the liquid line.
A vent grille is a vent cover through which air is blown into or out of a room for circulation back to the central heating or cooling unit. These are commonly found if you have heating or central air conditioning. A grille has no damper to control air flow, so air is left to flow freely. Grilles do not have the damper normally found on registers.