HVAC Flashcards
AHRI Certificate
The Air Conditioning, Heating & Refrigeration Institute (AHRI) is a globally recognized organization that measures and tests equipment efficiencies. HVAC units that are AHRI Certified have been through rigorous, unbiased testing to verify their energy efficiency.
Air Handler
An air handler, or air handling unit (often abbreviated to AHU), is a device used to regulate and circulate air as part of a heating, ventilating, and air-conditioning (HVAC) system.[1] An air handler is usually a large metal box containing a blower, heating or cooling elements, filter racks or chambers, sound attenuators, and dampers.[2] Air handlers usually connect to a ductwork ventilation system that distributes the conditioned air through the building and returns it to the AHU. Sometimes AHUs discharge (supply) and admit (return) air directly to and from the space served without ductwork
Small air handlers, for local use, are called terminal units, and may only include an air filter, coil, and blower; these simple terminal units are called blower coils or fan coil units. A larger air handler that conditions 100% outside air, and no recirculated air, is known as a makeup air unit (MAU) or fresh air handling unit (FAHU). An air handler designed for outdoor use, typically on roofs, is known as a packaged unit (PU) or rooftop unit (RTU).
Air Handling Unit
The indoor part of an air conditioner or heat pump that moves cooled or heated air throughout the ductwork of the home. Usually a large metal box containing important elements of an HVAC system that controls airflow and filtration
Awl
Used to punch holes or scribe lines into sheet metal so that it can be cut straight
Bioaerosols
Also known as biological aerosols, are tiny airborne particles that are biological in nature. High concentrations of them in indoor air can lead to respiratory problem/diagnosis and disease.
Block Load / Room by Room For ?
Essentially “block load” calculates heating and cooling loads for the entire conditioned space whereas room-by-room provides heating and cooling load calculation for individual rooms. Both options should result in the exact same heat loss and heat gain totals.
Blower
Component responsible for pushing air through the vents of your heating and air conditioning systems. Without it, the systems will not be able to circulate any heated or cooled air. It pulls hot air from the inside the home into the return and blows it across the evaporator coil
British Thermal Unit (BTU)
A measurement of heat energy. One BTU is the amount of heat required to raise one pound of water by one degree Fahrenheit. The higher the BTU rating, the greater the heating capacity of the system
Caulking Gun
Used to seal work in ducts and fill holes where needed.
Central Air-Conditioning
Central air conditioning is a system in which air is cooled at a central location and distributed to and from rooms by one or more fans and ductwork
Coil Fin Straightener
Used to straighten and clean coils to improve heat exchange and air flow when the AC condenser coil gets dirty
Comfort Consultants/Comfort Advisor/Estimators
Referred to as Selling Technicians in ServiceTitan. Comfort Advisors are typically those field employees that sell new HVAC systems
Compressor
This is what “squeezes” the refrigerant gas resulting in a high pressure/high temperature gas.
Condenser
A device or unit used to change a substance from its gaseous state to its liquid state by cooling it. This typically has a heat exchanger section that cools down and condenses incoming refrigerant vapor into liquid.
Condenser Coil
Used within the condenser, it is where the heat is removed from the refrigerant
Crack Heat Exchanger
A gas furnace’s heat exchanger is the furnace component that actually heats the air. It’s comprised of a set of tubes or coils that repeatedly loops through the airflow inside the furnace to heat the air. The shape of the coils depends on the type or model of your furnace. If there’s a possibility of your heat exchanger being cracked, don’t ignore it. A cracked heat exchanger is pretty serious
Cut-Ins
The installation of a new HVAC system generally at an existing establishment and not at a new construction site.
Delta T
Delta-T, often marked as ΔT (Δ – the Greek letter Delta), is a way of expressing temperature differences when conducting temperature tests and cooling performance comparison.
Door Re-hang
Doors may be removed during HVAC installation and then a field employee will need to be sent out to take care of this.
Door Re-set
Garage door is off it’s tracks.
Dry Charged Unit
An air conditioner or heat pump that is shipped “dry” and charged with refrigerant at the place of installation.
Dual Fuel
A comfort system that pairs an electric heat pump with a gas furnace and alternates between the two fuel sources to maximize comfort and efficiency
Ductwork
Refers to the system of metal or synthetic tubes that are used to move the air throughout the home
EER
A room air conditioner’s efficiency is measured by the energy efficiency ratio (EER). The EER is the ratio of the cooling capacity (in British thermal units [Btu] per hour) to the power input (in watts). The higher the EER rating, the more efficient the air conditioner.
Electronic Air Cleaner
Sometimes referred to as ionizers or air purifiers, use electrically charged filters to reduce the number of airborne contaminants in the home. As the air passes through the system, the cleaner uses the charged filters to attract and collect harmful particles from circulating into rooms
Electronic Air Cleaner
Sometimes referred to as ionizers or air purifiers, use electrically charged filters to reduce the number of airborne contaminants in the home. As the air passes through the system, the cleaner uses the charged filters to attract and collect harmful particles from circulating into rooms
Energy Efficiency Ratio (EER)
The ratio of cooling capacity to the power input (in watts). The higher the EER rating the more efficient the air conditioner
Energy Star®
A program of the U.S Environmental Protection Agency (EPA) designed to help consumers and businesses save money by choosing the most energy efficient systems and technologies
Evaporator Coil
Device that is used to absorb the heat from the air in your house by turning liquid refrigerant into a gaseous state (vapor) and then releasing it
Fan
Located on the condenser outside, the fan blows out the hot air that was taken from inside the home
Filter
Used to keep dust out of the house and provide, cool or hot, clean air
Gauges
Refrigeration gauges identify pressure for different types of refrigerants and determine if there is a leak in the system
Hand Seamers
Used to bend, shape, or flatten the sheet metal used in ductwork
Heat Pump
A heat pump is a device that transfers heat energy from a source of heat to what is called a thermal reservoir. Heat pumps move thermal energy in the opposite direction of spontaneous heat transfer, by absorbing heat from a cold space and releasing it to a warmer one. A heat pump uses external power to accomplish the work of transferring energy from the heat source to the heat sink.[1] The most common design of a heat pump involves four main components – a condenser, an expansion valve, an evaporator and a compressor. The heat transfer medium circulated through these components is called refrigerant.
HERS
Home Energy Rating System (HERS) testing examines a home’s energy efficiency and notes areas where energy efficiency can be improved
HVAC(R)
Stands for “Heating, Ventilation, and Air Conditioning” (sometimes referred to as HVACR where the R stands for “Refrigeration”), this is the most complex industry that we service if only because of the many ways companies handle the jobs themselves.
Typically, HVAC companies will sell the highest ticket jobs thanks to their sales being done in two parts: Salespeople (typically called something like “Comfort Advisors”) who go out to the home, build out an estimate based on the customers’ homes and needs, and provides multiple solutions via estimates. Once an estimate is sold, an install team will follow up and complete the installation. Typical pay structure for this industry is commission for sales reps, and hourly for their installers.
Also of note, memberships/service plans with recurring services (pre-paid visits such as a Heating tune up, AC refill, etc.) are a large revenue generator in this field simply because it gets a technician into a customer’s home and can generate a new job from a recurring services visit. This is one of the main revenue drivers for our HVAC customers.
Jobs include repair and installation of air conditioners, thermostats, etc. Waterproofing is another common job (the process of making an object or structure waterproof or water-resistant). Often, HVAC jobs require electrical work as well.
Large Customer Examples: Campbell & Company, Uptown, Tiger
Common Associations: Nexstar, SGI (Success Group International), ACCA (Air Conditioning Contractors of America), IHACI (Institute of Heating and Air Conditioning Industries)
Install Coordinator
Install coordinator is like the dispatcher of the install crews. They may also take on additional duties such as payroll, permits, etc
Manual J
Manual J is the protocol used for determining the amount of heating and cooling that a home requires to keep its occupants warm in the heating months and cool and dry in the cooling months
MERV
This term is used when describing air filter performance levels. The MERV rating ranges from lowest to highest in terms of filtration levels. Different household needs such as asthma, allergies, and pet dander would require you to use higher MERV rated products
Multimeter
Also known as a volt-ohm meter, is a handheld tester used to measure electrical voltage, current (amperage), and resistance. It is also used when working around the possibility of electrical hazards and live energy to test that a tool or an area is safe
NATE
This is an organization that certifies hvac technicians - like an excellence organization
NATE
This is an organization that certifies hvac technicians - like an excellence organization
Nitrogen Regulator
Acts as a pressure control valve
Over 10
Over 10 means that a system is over 10 years old. For a HVAC company “Over 10” is a short hand way to refer to an opportunity call.
PSI
Measurement of pressure commonly used to measure refrigerant. Refrigerant pressure standards will vary depending on type of refrigerant used. The pressure reading is an important diagnostic informant to what may be wrong with a system.
Psychrometer
A type of hydrometer that is used to measure the relative humidity or moisture content in the air
Pumps
Vacuum pump used to suck any moisture out of lines
Red Tagged
This term can have a few different meanings. The most common for our traditional ICP is that a furnace is cracked and has been redtagged due to risk of CO2 poisoning. Another common possibility is a gas leak. They “red tag” meaning that it can’t be used until repaired/replaced. In some states there may also be municipality reporting associated with red tagging something.
Refrigerant
A chemical that is typically found in either a fluid or gaseous state that absorbs heat from the rooms in a house, which then produces a cooling effect.
Refrigerant Tubing
Two lines that are connected to the outdoor air conditioner from the indoor evaporator coil. The two lines transfer refrigerant back and forth which is needed for the creation of cool A/C in the Summer or hot air in the Winter.
Return
For an HVAC system air is circulated through out a building/home. The air is gathered up and RETURNed to the system to be cooled. The return refers to the grill and duct work where the air is gathered. Typically larger than supply vents, this is used to gather air from various locations throughout the house. It is also used to maintain the home’s air pressure and filter out debris.
Roll Out (Gas Furnace)
Flame rollouts in gas furnaces and boilers are caused by a high concentration of combustion gases inside the combustion chamber.
Rough-in
Demo work, installing ductwork, line sets etc.
Sawzall
Also referred to as a reciprocating saw, is a machine-powered saw in which cutting is achieved through a push and pull method. It is used to cut through a variety of materials including old condensers, drywall, sheet metal pipes, wood, etc.
SEER
The efficiency of air conditioners is often rated by the seasonal energy efficiency ratio which is defined by the Air Conditioning, Heating, and Refrigeration Institute in its 2008 standard AHRI 210/240, Performance Rating of Unitary Air-Conditioning and Air-Source Heat Pump Equipment.
Sheet Metal Worker
Some shops have a sheet metal worker who uses sheet metal to create duct work.
Start Up
Firing up the system. Starting it up. Final check list complete
Subcooling
Normally, a refrigeration system has a subcooling stage, allowing technicians to be certain that the quality, in which the refrigerant reaches the next step on the cycle, is the desired one
Superheat
Superheat is critical in HVAC because it ensures the liquid refrigerant is boiled off before it leaves the evaporator and heads to the compressor
Supply
For an HVAC system air is circulated through out a building/home. The air is SUPPLY-ed to the building via the supplies. The supply refers to the grill and duct work where the air is supplied. The opposite of return air ducts, this where where the air is blown out from and into the rooms which comes directly from the A/C or heating unit in the house.
Thermostat
Device typically located on a wall inside the home that automatically regulates the temperature that has been set
Trim and Set
installing equipment and major materials grilles thermostats
TXV
The TXV is thermal expansion valve. The TXV can be expensive to replace for the homeowner. It can sometimes be a more difficult of complex repair for a HVAC technician. From wikipedia: “A thermal expansion valve or thermostatic expansion valve (often abbreviated as TEV, TXV, or TX valve) is a component in refrigeration and air conditioning systems that controls the amount of refrigerant released into the evaporator thereby keeping superheat, that is, the difference between the current refrigerant temperature at the evaporator outlet and its saturation temperature at the current pressure, at a stable value, ensuring that the only phase in which the refrigerant leaves the evaporator is vapor, and, at the same time, supplying the evaporator’s coils with the optimal amount of liquid refrigerant to achieve the optimal heat exchange rate allowed by that evaporator.”
Unitary/Ductless
Unitary system means a system which combines heating, cooling, and fan sections all in one(Packaged) or a few assemblies(Split). Package Unit and Split systems can be used as unitary system and centralized system.
VRF
Variable refrigerant flow (VRF), also known as variable refrigerant volume (VRV), is an HVAC technology invented by Daikin Industries, Ltd. in 1982.[1] Like ductless minisplits, VRFs use refrigerant as the cooling and heating medium. This refrigerant is conditioned by a single or multiple condensing units (which may be outdoors or indoors, water or air cooled), and is circulated within the building to multiple indoor units.[2] VRF systems, unlike conventional chiller-based systems, allow for varying degrees of cooling in only certain areas, reducing energy consumption.
