Glossary of Terms
AFUE -- The measurement for heating efficiency is AFUE (Annual Fuel Utilization Efficiency), which ranges from 80% to 97% for new systems. The higher the AFUE, the more efficiently the system performs, the greater your energy savings.
Airflow--The distribution or movement of air.
Air Handler -- The indoor part of an air conditioner or heat pump that moves cooled or heated air throughout the duct work of your home. An air handler is typically used in an all electric system in place of the furnace.
Balance Point (comfort and economic) Comfort balance point is referred to when the heating output at a particular outdoor temperature, usually about 30° F, is only capable of producing heated air from the duct approximately the same temperature as the human body. Anything below this temperature will yield cool air blowing out of the ducts and the potential for a cooler feeling in the house. Economic Balance point is the point where the heat pump is no longer more efficient that the furnace making the transition an economical issue rather than comfort.
Blower door -- A home performance tool used to measure how tight or leaky a structure is. This is a blower that gets sealed into an opening within the home. This blower is calibrated with a micromanometer to determine the amount of air required to keep a consistent pressure within the structure. This pressure is typically 50 pascals. The amount of air measured is typically in cubic feet per minutes (cfm). The result is presented as 2400cfm50, which would read as 2400 cubic feet per minute at 50 pascals.
Bioaerosols -- Microscopic living organisms suspended in the air that grow and multiply in warm, humid places.
Btu -- A British thermal unit is a unit 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.
BTU/hr -- The abbreviation for British thermal units per hour. The amount of heat required to raise one pound of water one degree fahrenheit per hour, a common measure of heat transfer rate.
Carbon Dioxide --Carbon Dioxide or CO2 is a greenhouse gas that is natural and harmless in small quantities, but as levels rise it can affect productivity and sleep. Most commonly produced indoors by the air we exhale, CO2 levels concentrate indoors with less ventilation. https://www.airthings.com/what-is-carbon-dioxide
High CO2 levels decrease productivity. According to Harvard research, high CO2 levels can decrease your productivity, cognitive abilities and general wellbeing. For example, if the CO2 concentration in the room exceeds 1000 parts per million, your cognitive function decreases by 15%. Worse yet, if CO2 levels reach 1400 ppm, your cognitive abilities drop by a staggering 50%. https://aranet.com/products/aranet4/
Carbon Monoxide -- Carbon Monoxide (CO) is a colorless, odorless gas produced by burning any fuel. CO is poisonous and symptoms of CO poisoning are similar to those of the flu: headaches, fatigue, shortness of breath, nausea and dizziness.
Central Air Conditioning System -- System in which air is treated at a central location and distributed to and from rooms by one or more fans and a series of ducts.
CFM -- Stands for Cubic Feet per Minute. This measurement indicates how many cubic feet of air pass by a stationary point in one minute. The higher the number, the more air is being moved through the ductwork by the system.
Coefficient Of Performance or COP (sometimes CP) -- of a heat pump is the ratio of the heating or cooling provided over the electrical energy consumed.
For example, the 2009 US average price per therm (100,000 BTU) of electricity was $3.38 while the average price per therm of natural gas was $1.16.[2] Using these prices, a heat pump with a COP of 3.5 in moderate climate would cost $0.97[3] to provide one therm of heat, while a high efficiency gas furnace with 95% efficiency would cost $1.22[4] to provide one therm of heat. http://en.wikipedia.org/wiki/Coefficient_of_performance
Compressor -- The part of the outdoor air conditioner or heat pump that compresses and pumps refrigerant to meet household cooling requirements.
Condensation -- The process by which a gas is changed into a liquid at constant temperature by heat removal.
Condenser Coil -- In an air conditioning system the outdoor unit is always the condensing coil. The condenser coil is the coil where heat is dissipated. A heat pump system has the ability to reverse it's flow of refrigerant so in cooling mode the outdoor unit is the condenser coil but in heating mode the indoor unit is the condenser coil.
This is why I typically refer to the outdoor or indoor coil to be clear regardless of the system.
Damper -- A movable plate, located in the duct work, that regulates airflow. Dampers are used to direct air to the areas that need it most. In a conventional system the dampers controlling rooms with little need for airflow are partially closed diverting the airflow to the rooms that need more airflow. In a zoned system the dampers are controlled by a computer to direct airflow to different sections of the house depending on each thermostat setting.
Decibel (DB) -- A decibel is a unit used to measure the relative intensity of sound.
Defrost Cycle --The process of removing ice or frost buildup from the outdoor coil during the heating season.
Direct Vent -- Pulls outside air for combustion and vents combustion gases directly outside.
Downflow Furnace -- A furnace that pulls in return air from the top and expels warm air at the bottom.
Ductwork -- The method by which air is channeled from the furnace or the blower coil throughout your home.
Electronic Air Cleaner -- An electronic device that filters out large particles and bioaerosols in indoor air.
Emergency Heat (Supplemental or Auxillary Heat) -- The back-up heat built into a heat pump system.
Energy Efficiency Ratio (EER) -- Means the ratio of the cooling capacity of the air conditioner in British Thermal Units per hour, to the total electrical input in watts under ARI-specified test conditions.
ENERGY STAR® -- An EPA (Environmental Protection Agency) designation attached to HVAC products that meet or exceed EPA guidelines for high-efficiency performance above the standard government minimums.
EPA -- The Environmental Protection Agency develops and enforces federal environmental regulations. The EPA oversees the nationwide Energy Star® program.
Evaporator Coil -- In an air conditioning system the indoor unit is always the evaporator coil. The evaporator coil is the coil where heat is absorbed. A heat pump system has the ability to reverse it's flow of refrigerant so in cooling mode the indoor unit is the evaporator coil but in heating mode the indoor unit is the condenser coil.
This is why I typically refer to the outdoor or indoor coil to be clear regardless of the system.
FAQ -- Stands for "frequently asked questions."
Filter -- A device used to remove dust and other particles from air for the purposes of reducing the load on the respiratory system and to protect the HVAC equipment. Filters vary greatly in particle arrestance; the higher the MERV rating, the better the filter.
Freon -- R22 refrigerant, also known as Freon, has been the HVAC industry standard refrigerant used in
the manufacture of central air conditioning systems. Because R22 refrigerant contributes to depleting the
ozone layer, the U.S. government has enacted a policy requiring that air conditioners and heat pumps no
longer use R22 refrigerant. If your existing A/C system has R22 refrigerant, it can be serviced and, if
necessary, recharged up to 1/1/2020. However, after 1/1/2020, refrigerant manufacturers must cease all
production of R22 refrigerant completely. If you are purchasing a new air conditioning system today,
consider one that uses the more environmentally friendly R410A refrigerant.
Heat Exchanger -- Located in the furnace, the heat exchanger transfers heat to the air that is then distributed throughout the house. The air passes by the outside while the flue gases, which contain undesirable gases and moisture, are safely contained on the inside.
Heat Pump -- A heat pump is an HVAC unit that heats or cools by moving heat. During the winter, a heat pump draws heat from outdoor air and circulates it through your home's air ducts. In the summer, it reverses the process and removes heat from your house and releases it outdoors.
Horizontal Right or Horizontal Left -- When an air handler or furnace is positioned on its side and circulates air to the left (horizontal left) or to the right (horizontal right) when looking at the front of the unit. Typically seen in an attic or crawl space installation.
Heating Seasonal Performance Factor (HSPF) --means the total heating output of a heat pump in British Thermal Units during its normal usage period for heating divided by the total electrical energy input in watt-hours during the same period.
Humidifier -- An indoor air quality device that introduces moisture to air as it passes from the furnace into the ductwork for distribution throughout the home.
Humidistat -- An automatic device used to maintain humidity at a fixed or adjustable set point.
HVAC -- Heating, Ventilation and Air Conditioning.
Indoor Coil -- See Evaporator Coil.
Insulation -- Any material that slows down the transfer of heat.
Load Calculation -- A mathematical design tool used to determine the heat gain and heat loss in a building so that properly sized air conditioning and heating equipment may be installed.
MERV Rating -- The MERV (Minimum Efficiency Reporting Value) rating of a filter describes the size of the holes in the filter that allow air to pass through. The higher the MERV rating, the smaller the holes in the filter, the higher the efficiency.
Micron -- A unit of measure equal to one millionth of a meter, or one thousandth of a millimeter.
Mini-split System --A Heating and/or cooling system that usually is duct less, often times for one portion of the house or addition, used to heat and cool individual areas, particularly if a Window Unit is not desired or no windows are present. They have incredibly high efficiencies for both heating and cooling. They are electric only (does not burn natural gas or propane). They tend to be most cost effective when no existing ductwork is present and retrofit to boiler / radiant heat very well
Natural-Draft Furnace (or hot water heater) -- A furnace in which the natural flow of air from around the furnace provides the air to support combustion. It also depends on the pressure created by the heat in the flue gases to force them out through the vent system.
Odors/Chemicals -- Air contaminants in the form of gases.
Operating Cost -- The day-to-day cost of running your home comfort equipment, based on daily energy use.
Outdoor Coil -- See Condenser Coil.
Particles (Particulate) -- Any substances measuring less than 100 microns in diameter. The EPA has found that small particles (less than 2.5 microns) are responsible for the health effects of greatest concern.
Programmable Thermostat -- A thermostat with the ability to alter the temperature at predetermined times to save energy during times when the house is not occupied. A programmable thermostat will typically save 15% off the gas bill
R410A Refrigerant -- A chlorine-free refrigerant that meets the EPA's newest, most stringent environmental guidelines.
Refrigerant -- A chemical that produces a cooling effect while expanding or vaporizing. Most residential air conditioning units contain the standard R-22 refrigerant, or Freon.
Refrigerant Lines -- Two copper lines that connect the outdoor portion of the air conditioner or heat pump to the indoor coil.
Return Air -- Air drawn into a heating unit after having been circulated from the heater's output supply to a room.
Reversing Valve -- A device in a heat pump that reverses the flow of refrigerant as the system is switched from cooling to heating.
Roof Top Unit (RTU) -- A commercial rooftop mounted packaged heating and cooling system
Scroll Compressor -- A specially designed compressor that works in a circular motion, as opposed to up-and-down piston action.
SEER -- The cooling performance of air conditioners and heat pumps is rated using the SEER (Seasonal Energy Efficiency Ratio) system, which ranges from 13.00 to 20.00 for new systems. The higher the SEER, the better the efficiency, the greater the energy savings.
Setpoint -- The temperature to which a thermostat is set for desired comfort level.
Split System -- A HVAC system in which some components are located inside the structure of the house and some are located outside. Split systems should be matched for optimal efficiency.
Subcooling -- Creating a drop in temperature by removing sensible heat from a refrigerant liquid.
Superheat -- Creating a rise in temperature by adding heat energy to a refrigeration vapor.
Supplementary Heat -- The auxiliary or emergency heat, usually electrical resistance heat, provided at temperatures below a heat pump's balance point.
Thermostat -- A temperature control device, typically found on a wall inside that consists of a series of sensors and relays that monitor and control the functions of a heating and cooling system.
Tonnage -- The unit of measure used in air conditioning to describe the cooling capacity of a system. One ton of cooling is based on the amount of heat needed to melt one ton (2000 lbs.) of ice in a 24 hour period. One ton of cooling is equal to 12,000 Btu/hr..
Two-Stage Operation -- Provides two levels of heating or cooling output for greater temperature control, energy efficiency and improved indoor air quality.
Upflow -- When an air handler or furnace is installed in an upright position and circulates air through the side or bottom and out through the top. Typically used in a basement or closet installation.
Vacuum Pump -- A pump used to remove air and moisture from a refrigeration system at a pressure below atmospheric pressure.
Variable Speed Motor -- A true Variable speed motor is an ECM motor or electronically commutated motor is a significantly more efficient electric motor, typically used as the blower motor, increasing efficiency as much as 75% over a conventional PSC blower motor, allowing superior customization, lower speeds which in turn increase comfort. These motors are particularly cost effective when the blower motor is run continuously for air filtration and purification saving the user $180-$360 per year with Cuyahoga counties electric rate of 6 cents per kilowatt hour.
Zoning -- A method of partitioning a home into independently controlled comfort zones for enhanced comfort and efficiency.
Airflow--The distribution or movement of air.
Air Handler -- The indoor part of an air conditioner or heat pump that moves cooled or heated air throughout the duct work of your home. An air handler is typically used in an all electric system in place of the furnace.
Balance Point (comfort and economic) Comfort balance point is referred to when the heating output at a particular outdoor temperature, usually about 30° F, is only capable of producing heated air from the duct approximately the same temperature as the human body. Anything below this temperature will yield cool air blowing out of the ducts and the potential for a cooler feeling in the house. Economic Balance point is the point where the heat pump is no longer more efficient that the furnace making the transition an economical issue rather than comfort.
Blower door -- A home performance tool used to measure how tight or leaky a structure is. This is a blower that gets sealed into an opening within the home. This blower is calibrated with a micromanometer to determine the amount of air required to keep a consistent pressure within the structure. This pressure is typically 50 pascals. The amount of air measured is typically in cubic feet per minutes (cfm). The result is presented as 2400cfm50, which would read as 2400 cubic feet per minute at 50 pascals.
Bioaerosols -- Microscopic living organisms suspended in the air that grow and multiply in warm, humid places.
Btu -- A British thermal unit is a unit 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.
BTU/hr -- The abbreviation for British thermal units per hour. The amount of heat required to raise one pound of water one degree fahrenheit per hour, a common measure of heat transfer rate.
Carbon Dioxide --Carbon Dioxide or CO2 is a greenhouse gas that is natural and harmless in small quantities, but as levels rise it can affect productivity and sleep. Most commonly produced indoors by the air we exhale, CO2 levels concentrate indoors with less ventilation. https://www.airthings.com/what-is-carbon-dioxide
High CO2 levels decrease productivity. According to Harvard research, high CO2 levels can decrease your productivity, cognitive abilities and general wellbeing. For example, if the CO2 concentration in the room exceeds 1000 parts per million, your cognitive function decreases by 15%. Worse yet, if CO2 levels reach 1400 ppm, your cognitive abilities drop by a staggering 50%. https://aranet.com/products/aranet4/
Carbon Monoxide -- Carbon Monoxide (CO) is a colorless, odorless gas produced by burning any fuel. CO is poisonous and symptoms of CO poisoning are similar to those of the flu: headaches, fatigue, shortness of breath, nausea and dizziness.
Central Air Conditioning System -- System in which air is treated at a central location and distributed to and from rooms by one or more fans and a series of ducts.
CFM -- Stands for Cubic Feet per Minute. This measurement indicates how many cubic feet of air pass by a stationary point in one minute. The higher the number, the more air is being moved through the ductwork by the system.
Coefficient Of Performance or COP (sometimes CP) -- of a heat pump is the ratio of the heating or cooling provided over the electrical energy consumed.
For example, the 2009 US average price per therm (100,000 BTU) of electricity was $3.38 while the average price per therm of natural gas was $1.16.[2] Using these prices, a heat pump with a COP of 3.5 in moderate climate would cost $0.97[3] to provide one therm of heat, while a high efficiency gas furnace with 95% efficiency would cost $1.22[4] to provide one therm of heat. http://en.wikipedia.org/wiki/Coefficient_of_performance
Compressor -- The part of the outdoor air conditioner or heat pump that compresses and pumps refrigerant to meet household cooling requirements.
Condensation -- The process by which a gas is changed into a liquid at constant temperature by heat removal.
Condenser Coil -- In an air conditioning system the outdoor unit is always the condensing coil. The condenser coil is the coil where heat is dissipated. A heat pump system has the ability to reverse it's flow of refrigerant so in cooling mode the outdoor unit is the condenser coil but in heating mode the indoor unit is the condenser coil.
This is why I typically refer to the outdoor or indoor coil to be clear regardless of the system.
Damper -- A movable plate, located in the duct work, that regulates airflow. Dampers are used to direct air to the areas that need it most. In a conventional system the dampers controlling rooms with little need for airflow are partially closed diverting the airflow to the rooms that need more airflow. In a zoned system the dampers are controlled by a computer to direct airflow to different sections of the house depending on each thermostat setting.
Decibel (DB) -- A decibel is a unit used to measure the relative intensity of sound.
Defrost Cycle --The process of removing ice or frost buildup from the outdoor coil during the heating season.
Direct Vent -- Pulls outside air for combustion and vents combustion gases directly outside.
Downflow Furnace -- A furnace that pulls in return air from the top and expels warm air at the bottom.
Ductwork -- The method by which air is channeled from the furnace or the blower coil throughout your home.
Electronic Air Cleaner -- An electronic device that filters out large particles and bioaerosols in indoor air.
Emergency Heat (Supplemental or Auxillary Heat) -- The back-up heat built into a heat pump system.
Energy Efficiency Ratio (EER) -- Means the ratio of the cooling capacity of the air conditioner in British Thermal Units per hour, to the total electrical input in watts under ARI-specified test conditions.
ENERGY STAR® -- An EPA (Environmental Protection Agency) designation attached to HVAC products that meet or exceed EPA guidelines for high-efficiency performance above the standard government minimums.
EPA -- The Environmental Protection Agency develops and enforces federal environmental regulations. The EPA oversees the nationwide Energy Star® program.
Evaporator Coil -- In an air conditioning system the indoor unit is always the evaporator coil. The evaporator coil is the coil where heat is absorbed. A heat pump system has the ability to reverse it's flow of refrigerant so in cooling mode the indoor unit is the evaporator coil but in heating mode the indoor unit is the condenser coil.
This is why I typically refer to the outdoor or indoor coil to be clear regardless of the system.
FAQ -- Stands for "frequently asked questions."
Filter -- A device used to remove dust and other particles from air for the purposes of reducing the load on the respiratory system and to protect the HVAC equipment. Filters vary greatly in particle arrestance; the higher the MERV rating, the better the filter.
Freon -- R22 refrigerant, also known as Freon, has been the HVAC industry standard refrigerant used in
the manufacture of central air conditioning systems. Because R22 refrigerant contributes to depleting the
ozone layer, the U.S. government has enacted a policy requiring that air conditioners and heat pumps no
longer use R22 refrigerant. If your existing A/C system has R22 refrigerant, it can be serviced and, if
necessary, recharged up to 1/1/2020. However, after 1/1/2020, refrigerant manufacturers must cease all
production of R22 refrigerant completely. If you are purchasing a new air conditioning system today,
consider one that uses the more environmentally friendly R410A refrigerant.
Heat Exchanger -- Located in the furnace, the heat exchanger transfers heat to the air that is then distributed throughout the house. The air passes by the outside while the flue gases, which contain undesirable gases and moisture, are safely contained on the inside.
Heat Pump -- A heat pump is an HVAC unit that heats or cools by moving heat. During the winter, a heat pump draws heat from outdoor air and circulates it through your home's air ducts. In the summer, it reverses the process and removes heat from your house and releases it outdoors.
Horizontal Right or Horizontal Left -- When an air handler or furnace is positioned on its side and circulates air to the left (horizontal left) or to the right (horizontal right) when looking at the front of the unit. Typically seen in an attic or crawl space installation.
Heating Seasonal Performance Factor (HSPF) --means the total heating output of a heat pump in British Thermal Units during its normal usage period for heating divided by the total electrical energy input in watt-hours during the same period.
Humidifier -- An indoor air quality device that introduces moisture to air as it passes from the furnace into the ductwork for distribution throughout the home.
Humidistat -- An automatic device used to maintain humidity at a fixed or adjustable set point.
HVAC -- Heating, Ventilation and Air Conditioning.
Indoor Coil -- See Evaporator Coil.
Insulation -- Any material that slows down the transfer of heat.
Load Calculation -- A mathematical design tool used to determine the heat gain and heat loss in a building so that properly sized air conditioning and heating equipment may be installed.
MERV Rating -- The MERV (Minimum Efficiency Reporting Value) rating of a filter describes the size of the holes in the filter that allow air to pass through. The higher the MERV rating, the smaller the holes in the filter, the higher the efficiency.
Micron -- A unit of measure equal to one millionth of a meter, or one thousandth of a millimeter.
Mini-split System --A Heating and/or cooling system that usually is duct less, often times for one portion of the house or addition, used to heat and cool individual areas, particularly if a Window Unit is not desired or no windows are present. They have incredibly high efficiencies for both heating and cooling. They are electric only (does not burn natural gas or propane). They tend to be most cost effective when no existing ductwork is present and retrofit to boiler / radiant heat very well
Natural-Draft Furnace (or hot water heater) -- A furnace in which the natural flow of air from around the furnace provides the air to support combustion. It also depends on the pressure created by the heat in the flue gases to force them out through the vent system.
Odors/Chemicals -- Air contaminants in the form of gases.
Operating Cost -- The day-to-day cost of running your home comfort equipment, based on daily energy use.
Outdoor Coil -- See Condenser Coil.
Particles (Particulate) -- Any substances measuring less than 100 microns in diameter. The EPA has found that small particles (less than 2.5 microns) are responsible for the health effects of greatest concern.
Programmable Thermostat -- A thermostat with the ability to alter the temperature at predetermined times to save energy during times when the house is not occupied. A programmable thermostat will typically save 15% off the gas bill
R410A Refrigerant -- A chlorine-free refrigerant that meets the EPA's newest, most stringent environmental guidelines.
Refrigerant -- A chemical that produces a cooling effect while expanding or vaporizing. Most residential air conditioning units contain the standard R-22 refrigerant, or Freon.
Refrigerant Lines -- Two copper lines that connect the outdoor portion of the air conditioner or heat pump to the indoor coil.
Return Air -- Air drawn into a heating unit after having been circulated from the heater's output supply to a room.
Reversing Valve -- A device in a heat pump that reverses the flow of refrigerant as the system is switched from cooling to heating.
Roof Top Unit (RTU) -- A commercial rooftop mounted packaged heating and cooling system
Scroll Compressor -- A specially designed compressor that works in a circular motion, as opposed to up-and-down piston action.
SEER -- The cooling performance of air conditioners and heat pumps is rated using the SEER (Seasonal Energy Efficiency Ratio) system, which ranges from 13.00 to 20.00 for new systems. The higher the SEER, the better the efficiency, the greater the energy savings.
Setpoint -- The temperature to which a thermostat is set for desired comfort level.
Split System -- A HVAC system in which some components are located inside the structure of the house and some are located outside. Split systems should be matched for optimal efficiency.
Subcooling -- Creating a drop in temperature by removing sensible heat from a refrigerant liquid.
Superheat -- Creating a rise in temperature by adding heat energy to a refrigeration vapor.
Supplementary Heat -- The auxiliary or emergency heat, usually electrical resistance heat, provided at temperatures below a heat pump's balance point.
Thermostat -- A temperature control device, typically found on a wall inside that consists of a series of sensors and relays that monitor and control the functions of a heating and cooling system.
Tonnage -- The unit of measure used in air conditioning to describe the cooling capacity of a system. One ton of cooling is based on the amount of heat needed to melt one ton (2000 lbs.) of ice in a 24 hour period. One ton of cooling is equal to 12,000 Btu/hr..
Two-Stage Operation -- Provides two levels of heating or cooling output for greater temperature control, energy efficiency and improved indoor air quality.
Upflow -- When an air handler or furnace is installed in an upright position and circulates air through the side or bottom and out through the top. Typically used in a basement or closet installation.
Vacuum Pump -- A pump used to remove air and moisture from a refrigeration system at a pressure below atmospheric pressure.
Variable Speed Motor -- A true Variable speed motor is an ECM motor or electronically commutated motor is a significantly more efficient electric motor, typically used as the blower motor, increasing efficiency as much as 75% over a conventional PSC blower motor, allowing superior customization, lower speeds which in turn increase comfort. These motors are particularly cost effective when the blower motor is run continuously for air filtration and purification saving the user $180-$360 per year with Cuyahoga counties electric rate of 6 cents per kilowatt hour.
Zoning -- A method of partitioning a home into independently controlled comfort zones for enhanced comfort and efficiency.
